# Question
Title: How could I add fire-like lighting to Rivendell?
I'd love to add lights to the Rivendell set to improve the look of the displayed model in low light.

Ideally, the lights would provide a flame-like effect where appropriate.

What is the best way to do this using official LEGO parts?

# Answer
Here's a still photo showing the final look that I came up with:

Here's an animation attempting to capture the subtle flame effect:

## Parts

I've used 3 City Powered Up hubs (28738) in this modification:

I used 5 Powered Up lights (88005-1) connected to those hubs:

I also used a few very common parts to make minor modifications to the model and secure the lights.

## Modifications

This set is composed of three distinct sections that can be moved independently. I chose to maintain this independence for easy portability.

### Left Section

From left to right, the first section is the tower and the bedroom. I chose the hide the battery box where the bookshelf would have been in the lower room:

The hub itself provides a modest amount of light on the lower level and drives an LED in the roof of the bedroom:

The second LED on that pair snakes up to the top of the tower:

### Center Section

For the center section, I chose to hide the battery box in the roof. I found that it fits quite nicely once it gets wiggled into position:

One pair of LEDs is used to light the main section. I've attached them via 1x2 Technic bricks in the rafters above the shards of Narsil:

The second set of lights from this hub are split up. One goes to the small tower:

The other light is hidden in roof of the small structure jutting out from the main hall:

### Right Section

One pair of lights is used under the bridge to accent the water. These are affixed to a pair of 1x2 Technic bricks placed under the bridge:

The second set of lights are split up. One provides general moonlight-like illuminate for the gazebo:

The final light is placed behind the fire for the forge. It is attached to a Technic brick that replaced the black panel behind the fire in the original build:

## Software

I wanted to use the City Hubs for this project, as they are relatively small, widely available, and most compatible with System building. Unfortunately, these hubs can't be used without a constant connection to a smart device using the default firmware.

This limitation can be overcome using Pybricks. I wrote some basic code to the hub that would turn on any attached lights without the need for a smart device. From there, it is fairly straightforward to add a flickering algorithm.

While I was making things more complicated, I figured that it also made sense to leverage the RGB LED built into the hubs. I set this to also flicker in a nice orange hue. The code for all of this is available on Github if its useful to anyone.

I like the final look of the flickering quite well. Here's my attempt to capture it again:

## Final Model

Here are few shots from various parts of the model showing off the lighting:
> 21 votes

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Tags: set-modification, lighting
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title: Identification of rare LEGO DUPLO piece

text:
# Question
Title: Identification of rare LEGO DUPLO piece
Can you please help me identify what is this LEGO DUPLO cube? I received it inside package of old cubes I bought. It has shorter studs than normal ones, seems quite old. Material and its firmness makes me think that it is probably original DUPLO. I am very curious if it some of older piece or if it is just some "reject piece".

The size of label inside studs is "LEGO" and its larger than labels "LEGO" or "DUPLO" inside my other cubes.

# Answer
According to this post from 2012, the studs on Duplo bricks were changed somewhere in the 90s to be taller and have thinner walls.

Your brick is a genuine Duplo brick, it's just old.
> 5 votes

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Tags: part-identification, duplo
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# Question
Title: Brick, Round Corner and/or Plate, Round Corner with Curved Cutout fitting radius of 88293 - Brick, Round Corner 3 x 3 x 2 Dome Top
I would like to build a rounded edge with 713 - Plate, Round Curved 4 x 8 Right as base and the 88293 - Brick, Round Corner 3 x 3 x 2 Dome Top on top.

Are there any rounded corner bricks or rounded corner plates (with curved cutout) that fits the radius of the 713 and 88293?

Or is there a construction technique that closely matches the radius?

# Answer
> 3 votes
To my knowledge there are no 3x3 macaroni bricks like you'd really like to be able to use here. There are 2x2 and 4x4 macaroni bricks:

A 3x3 plate exists, but it actually has an outer radius of 2 and a short straight segment:

There are some parts that might be useful, depending on exactly what you are trying to accomplish. There is a 3x3 round window element that could be useful if you are willing to add glass from floor to ceiling:

There is also a half-circle panel in this radius the could be useful:

3x3 wedge bricks could be an option if you can compromise on having a truly round edge:

There are also various ways you can get close to this angle using studs-not-on-top techniques. This can be especially useful if you are going for a brick or stone look. Here's one example:

That's not quite the 3x3 corner you are looking for, but the basic idea could be adapted to best suit your particular needs.

Here are some other possible ideas from existing sets. The towers in Kinddoms Joust:

The lighthouse in Lighthouse Point. This uses 2x2 macaroni bricks to build a not-quite-round 3x3 corner:

The windows on the Pet Shop achieve a good estimation of this radius using 2x2 bricks and hinge plates:

Here's the technique in detail:

Hopefully something in there is useful for inspiration. Feel free to ask for clarification via comments or ask other new questions about how to solve specific issues in your build.

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Tags: moc
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title: Lego Mindstorms EV3 broken screen cable

text:
# Question
Title: Lego Mindstorms EV3 broken screen cable
While taking apart my EV3 brick I accidently pulled on the ribbon cable connecting the screen to the motherboard too hard and it broke.

I figured I could just get a replacement fpc ribbon cable with the same number of pins and swap out the cable, but turns out the other end is soldered to the screen, so that isn't going to work.

I looked around a lot on the Internet and found several other people with the same issue, but no solutions to the problem. Any advice on what I can do from here?

# Answer
> 4 votes
First of all: before doing anything else, contact LEGO customer support. There's nothing to lose by doing so.

---

According to the video at https://www.youtube.com/watch?v=gPNJC5Uz9HY , it's possible to replace the screen with a 1.8 inch colour TFT display with the aid of a flat ribbon adaptor.

I'm unsure if you would need to replace the Lego firmware with https://www.ev3dev.org/ or not.

---

Edit: Lego offers electronic schematics of the EV3 as part of the "Hardware developer kit" that can be downloaded from https://education.lego.com/en-us/product-resources/mindstorms-ev3/downloads/developer-kits . It tells us that the display connects through SPI, and contains this diagram of special relevance:

You should be able to connect any SPI display, which would need 5 connections: +3.3V (or `VDDA`), 0V (or `GND`), clock (`CLK`), `MOSI` (or `DIN` or `RX` in a SPI peripheral), and `CS` (or `SS`). Be aware that the nomenclature for SPI is confusing. The screen does not send data back to the board, so a `MISO`/`DOUT`/`TX` connection is not needed.

The stock firmware ***should*** work with any monochrome SPI display, but we hobbyists cannot offer you any guarantee at all.

---

Anyway, the original screen seems to use a pretty standard 18-pin 1.0mm-pitch ribbon cable. You should be able to unsolder it and replace with a new one. But since the connector at the board is a 18-pin 0.5mm-pitch, you'd need to use an adaptor like the aforementioned one.

Bear in mind that soldering tracks with a 1.0mm pitch requires precision soldering skills (and you can imagine that 0.5mm pitch will just be harder). I strongly recommend practicing your soldering skills first.

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Edit: According to the folks over at the Electronics stackexchange, it's possible to repair a flat ribbon cable.

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Tags: ev3, mindstorms, repair
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# Question
Title: Can someone identify what set(s) these three bags belong to?
My son just bought a bag of LEGO and it contained these three bags. Does anyone know what set or sets they belong to? He would greatly appreciate knowing.

Thanks!

# Answer
It looks like these bags came from 76104-1 - The Hulkbuster Smash-Up:

Those 3 bags can be used to build the Hulkbuster from that set:

The instructions for this are available via Rebrickable.
> 2 votes

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Tags: set-identification
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title: What sets are in these mixed bags?

text:
# Question
Title: What sets are in these mixed bags?
I don't have the instructions nor the original box so I am unsure what set these are. Does anyone know what are the names of these Lego sets? Where to find the instructions?

1

2

3

4

5

6

7

# Answer
> 4 votes
Apparently you have a large amount of sets from different themes and eras mixed thoroughly, which only allows the identification of a few sets that have quite distinct pieces. You could pick out the pieces for those sets and try to identify the remaining heap starting by the most unusual pieces.

For instructions I'd recommend checking Brickset. For example if you need the documents for 3847: Magma Monster, you'd look up that set and find the instructions below the main image.

---

Now, for your photos:

The balloon tires in the first image are called Tire 81.6 x 38 R Balloon, available in 16 sets. The thinner tire is called Tire 94.2mm D. x 22mm Motorcycle Racing Tread, available in 8 sets. The Orange Dish 8 x 8, as identified by Phil B., appeared in 3 SpongeBob sets from 2006 and a city set from 2010, besides an obscure FIRST LEGO League set.

The baseplate in image #2 is Baseplate, Raised 32 x 48 x 6 with Level Front, contained in 3 sets in gray and two in tan (presumably the one under it has the same pattern).

The wings in the third image are Wing Plate 20 x 56 with 6 x 10 Cutout and No Holes in dark bluish gray, these are definitely from 7683 - Fight on the Flying Wing.

The orange baseplate in image #5 is Orange Baseplate 16 x 16, from 3847 - Magma Monster.

Images #4, #5, #6 and #7 depict seemingly unopened bags, which would mean their contents belong to a single set.

The top bag of #6 has *Technic Engine Cylinder with Side Slots (2850a)*, *Technic, Liftarm, Modified Bent Thick 1 x 11.5 Double (32009)* and *Technic, Gear 40 Tooth (3649)*, which together with the red fairing have only appeared in 8051 Motorbike.

Bag #1 here seems to be from 8088: ARC-170 Starfighter, as the *Dark Green Brick, Round 2 x 2 Dome Top with Pearl Dark Gray Pattern (R4-P44)* only appears in that single set.

Image #6 bag #2 has both Dark Tan Wheel 31mm D. x 15mm Technic and a *Light Bluish Gray Technic, Brick 1 x 14 with Holes*, together only ever released in 8096: Emperor Palpatine's Shuttle.

Bag #3 of Image #6 seems to be from 7930: Bounty Hunter Assault Gunship based on the *Dark Bluish Gray Technic, Axle 8L with Stop*, *Dark Bluish Gray Plate, Round 4 x 4 with Hole*, *Dark Bluish Gray Wheel 31mm D. x 15mm Technic*, *Yellow Cylinder 4 x 4 x 1 2/3 with Pin Holes and Center Bar* and *Dark Green Cylinder Half 2 x 4 x 5 with 1 x 2 Cutout*.

On the bottom left, bag #4 has a *Light Bluish Gray Technic, Axle Connector Hub with 3 Axles*, a *White Plate 4 x 6* and most importantly one *White Tile 2 x 2 with Groove with Ninjago Cracked Red Skull on Black Circle Pattern*, which only appear together in 2506: Skull Truck.

The packages in image #7 are way too hard to identify, since they are not laid out neatly as in #6, so partially overlap each other and the loose parts underneath them, so please upload a separate image in the style of #6 if your own efforts remain unsuccessful.

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Tags: set-identification
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title: Convert 9V train to Powered Up

text:
# Question
Title: Convert 9V train to Powered Up
This is a follow-up from question "Can I convert my train 9V 4563 to the Power Functions motor?", now that *Power Functions* motors have been phased out in favour of *Powered Up* motors.

How can I convert a train locomotive from the 9V system to the Powered Up system?

Let's assume the oldest 9V locomotive, the one from set 4563-1.

# Answer
This is possible, if you place the hub in the closed van and couple the van behind the locomotive. Swapping out the 9v motor for the Powered Up motor is straightforward; you will then need to remove a 1x2 brick from the back of the locomotive cab and a 1x2 panel from the front of the van to allow the wire to pass through.

I would also suggest modifying the van roof so that it is easier to reach the power switch on the hub.

Adding lighting using 88005 is left as an exercise for the interested reader.
> 3 votes

# Answer
> Let's assume the oldest 9V locomotive, the one from set 4563-1.

I don't think you can convert that locomotive without dramitically changing it's appearance.

The basic components of a powered-up locomotive are a train motor and a hub, the train motor is basically the same size/shape as the old 9V track powered motor but the hub is a large additional component to accomodate.

There are a few different hubs, but the one included in the train sets is 4 studs wide. That basically means that either the section of the locomotive where the hub is located ends up at least 6 studs wide, or the sides of the hub and possiblly the connectors plugged into the hub will be visible.

It may be possible to put the hub in a wagon pulled behind the locomotive to try and preserve the appearance of the locomotive, but I expect wire management to be a challange.
> 2 votes

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Tags: motor, trains, powered-up
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# Question
Title: What Harry Potter set is this assembly from?
I have been gifted a lot of 10+ years old LEGO. I don't have any instructions books. Any idea what sets could this be so I could try to find them online please?

# Answer
> 1 votes
That looks like two Slope 2x2 45° in sand green and a Light Brick 2x3x 1 1/3.

The only set containing both those parts is 4738-1 Hagrid's Hut (3rd edition).

(Now that you know the set number, you can search for instructions in Lego's customer support webpages)

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Tags: set-identification, model-identification
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# Question
Title: How can I prevent rubber bands disintegrating?
These two answers partially answer this question., but I think it's worth its own question to find more options in a more comprehensive answer.

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Old Lego rubber bands are known to become brittle over time and break. The two questions linked above indicate that exposure to oxygen or light is the cause, and that sealing rubber bands in an airtight bag is one solution.

In my experience it has only been rubber bands with a square cross-section that decay. I have not (yet) had one break with a round cross-section.

What other ways are there to safely keep rubber bands for long periods of time, both for storage and display?

# Answer
In addition to exposure to heat and UV light (as highlighted in the linked question):

* Temperature fluctuations can cause the rubber to expand and contract which will weaken the rubber.
* Certain cleaning solvents used on the model may cause damage to the material, it might be best to remove the rubber bands when cleaning models.

There are specific rubber coatings available that can help maintain the elasticity and flexibility of rubber bands. One particular product that I am familiar with for rubber band magic is 'Elastraflex' which is quite pricey and may not necessarily work for rubber bands manufactured by LEGO.

Unfortunately unlike LEGO bricks, rubber bands have a much shorter lifespan when in use or in storage due to the nature of their material.

It may be more economical to buy a pack of non-LEGO rubber bands that have similar properties to LEGO-made bands and storing unused bands in sealed plastic bags. There is a good study of review of alternative options here.
> 1 votes

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Tags: repair, storage, durability, rubber-bands
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# Question
Title: Lego Gray, green, and black parts. What set would these parts belong to?
Lego Gray, green, and black parts. What set would these parts belong to? Could you help me identify the set that they go to?

# Answer
You've got four pieces of part 30246 Panel 3 x 4 x 6 Turret Wall with Window, in light bluish gray.

It's a relatively rare part - only appears in 18 sets, and only 2 of those sets have 4 or more of it. The green roof slopes tell me it's Bowser's Castle Boss Battle.
> 2 votes

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Tags: set-identification
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title: Mostly gray with two dark gray wheels

text:
# Question
Title: Mostly gray with two dark gray wheels
Mostly gray with two dark gray wheels. What set would they go to?

# Answer
> 1 votes
Half cylinder 3 x 6 plus Viking wagon wheel means 75292-1 The Razor Crest.

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Tags: set-identification
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# Question
Title: Here I have mostly white and yellow Legos bu need the set they go to
Here I have mostly white and yellow Legos bu need the set they go to. Can you help identify the set?

# Answer
> 1 votes
Pearl Gold Plate, Modified 1 x 1 with Tooth Vertical in pearl gold plus Plate, Modified 1 x 2 with 3 Teeth in white plus Slope, Curved 6 x 1 Inverted in bright light orange (not yellow!) means 41179-1 Queen Dragon's Rescue.

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Tags: set-identification
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# Question
Title: I have these two bags. Top one is mostly grays. Bottom mostly whites with blues and yellows and one gold piece
I have these two bags. Top one is mostly grays. Bottom mostly whites with blues and yellows and one gold piece. Would you know the set they go to?

# Answer
> 0 votes
The top bag appears to be from one of these two Death Stars (almost the same set).

Based on this search for sets with these three parts:

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Tags: set-identification
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# Question
Title: Which Harry Potter set is this table from?
I have been gifted a lot of 10 + years old Lego. I don't have any instructions books. Any idea what sets could these be so I could try to find them online please?

# Answer
I can identify the following parts:

* 2 of "Cheese slope" in reddish brown
* 2 of 1x1 round plate in trans-**neon**-orange
* 2 of 2x8 plate in dark tan

A search based on that criteria yields only one result: set 4182 "The Cannibal Escape" from the Pirates of the Caribbean franchise.

One of the sub-assemblies in the set resembles the one in your photograph very closely:

Alas, you don't have a Harry Potter table. You have a cannibal bonfire.
> 2 votes

# Answer
**Update**: this answer is based on a false premise and is therefore invalid. See IvanSanchez's answer instead.

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The photo clearly shows 2 of *Reddish Brown Plate, Modified 1 x 2 with 1 Stud with Groove (Jumper)* and *Trans-Orange Plate, Round 1 x 1*, and 4 each of *Reddish Brown Plate 1 x 4* and *Reddish Brown Slope 30 1 x 1 x 2/3*. There were only two sets in which all of these have appeared: 79003: An Unexpected Gathering and 10236: Ewok Village - UCS, but neither of these have a 2x8 plate in any colours besides black, green or reddish brown - none of which corresponds to the ones your photo depicts.

So this sub-assembly must not have come from an official set, or at least some parts have been added to it.

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Edit based on Henrik's comment:

Updating the search to include piece 15573 (*Modified 1 x 2 with 1 Stud with Groove and Bottom Stud Holder (Jumper)*) results in matches for 71040 Disney Castle (contains only dark bluish gray and white 2x8 plates), 70677 Land Bounty (just reddish brown 2x8), 40346 Legoland Park (green and white), 910003 Mountain Windmill (reddish brown) and 75220 Sandcrawler (which has the *Tile, Modified 1 x 1 with Open O Clip* only in dark bluish gray instead of black).

Switching out the jumper plate with groove (3794b) to the one without (3794a) yields no additional candidates.
> 0 votes

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Tags: set-identification, harry-potter
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# Question
Title: I am trying to find the set these Legos belong to
I am trying to find the set these polybags with LEGO bricks belong to. Can you help me with identifying which set they belong to?

# Answer
> 2 votes
**Bag 1:**

It is the **Amusement Park Roller Coaster (Item No: 41130)**

The Yellow Dish 6 x 6 Inverted (Radar) is very seldom, so I searched for sets including this dish and found 41130 Amusement Park Roller Coaster.

Below the yellow dish you see a seldom Minifigure, Utensil Dish 3 x 3 (Item No: 6256) in the picture.

**Bag 2:** This bag is part of the **Death Star - UCS (Item No: 10188-1)**

I used the following items in the picture for identification:

* Dark Bluish Gray Technic, Brick 1 x 2 with Axle Hole (32064)
* Black Technic, Gear 12 Tooth Double Bevel (32270)
* Dark Bluish Gray Technic, Axle and Pin Connector Perpendicular Double Split (41678)

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Tags: set-identification
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# Question
Title: I have these Legos that are reds, browns, and grays. Trying to find the set
I have these Legos that are reds, browns, and grays. Trying to find the set. What set would they go to?

# Answer
> 2 votes
Base on 3 parts that identified:

* 8x8 plate w/ 4 feet (66790) in Red
* 4x4 plate w/ 4 feet (66792) in Dark Orange
* And an 3x3 round tile (67095) in LBG

If finding all 3 identified parts on BL results.

This refers to set # 71380: Master Your Adventure

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Tags: set-identification
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# Question
Title: What is this part? Grey, 3 studs long, with two pins and an axle hole
Grey Lego piece. Says LEGO inside piece, but no ID number.

Thank you!

# Answer
> 4 votes
That's part 4261, Technic steering arm.

It's a relatively old part (last produced in 2005 AFAICS), and it was used as part of the wheel steering mechanism in Technic vehicles.

The idea is to use two steering arms; keep the ends with the two pins in a fixed position, and link the ends with a bar that can swivel either way. In the mechanism depicted above, the swiveling 1x8 plate with toothed ends is on top of a 1x4 tile and attached to a gear rack, which most usually would be connected to a steering wheel via gears and axles. Rotating the steering wheel would move the gear rack side to side, causing the steering arms to rotate around the fixed point, and therefore steering the wheels attached to them.

# Answer
> 0 votes
As Ivan says it's part 4261 "Technic Steering arm" and was a core part of steering mechanisms in old style (studded) Technic.

Two steering arms were sandwiched either between two Technic plates "with toothed ends" (usually the 1x8 version part 4442) or one plate with toothed ends and a "steering rack top" (part 2792).

An axle with pin (part 3749) was placed in the cross axle holes on the steering arms and a rack to drive the steering was attached to them. There were several different rack arrangements used.

* A setup like shown in Ivan's answer, where a separate rack was placed on top of a plate with toothed ends.
* A flat gear rack with integrated holes (part 6630)
* A round steering rack (part 2791). This was used in conjunction with the "steering rack top", "steering gear holder" (part 2790) and 8 tooth gear (part 3647). This setup provided a really easy and compact way to build a manually controlled steering mechanism with an adjustable steering column angle.

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Tags: part-identification, technic, piece-information
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# Question
Title: I have a polybag of LEGO pieces and need the set they go with
I have a polybag of LEGO pieces and need the set they go with.

There is one 6x6 large black square and ten light gray 1x2x2 with a small bag inside.

What set are they a part of?

# Answer
> 6 votes
This is 41611: Marty McFly & Doc Brown, based on *Black Plate 6 x 6*, two of *Yellow Brick, Round 2 x 2 with Axle Hole*, at least 8 *Red Brick, Modified 1 x 1 with Headlight* and the *Black Brick, Modified 1 x 2 x 2/3 with Studs on Sides*.

For future reference, you too can use Bricklink to identify the sets by entering the known parts into this form, to get an answer like this.

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Tags: set-identification
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# Question
Title: Can somebody help me find out what set this bag belongs to?
I found a Little bag from a larger set at a yard sale, and im trying to find out what set it belongs to. It comes with a bunch of lime green pieces, some are also gray and red.

# Answer
Based on the parts:

* Light Bluish Gray Technic, Axle and Pin Connector Perpendicular 3L with Center Pin Hole
* Lime Technic, Axle and Pin Connector Perpendicular 3L with 2 Pin Holes
* Red Technic, Axle and Pin Connector Perpendicular Double
* Lime Slope, Curved 2 x 2 x 2/3

this must be 42138: Ford Mustang Shelby GT500.
> 3 votes

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Tags: set-identification, piece-information
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# Question
Title: What set would these Lego parts belong with?
What set would these Lego parts belong with? Whites, light gray, and blacks. Bag is labled #2

# Answer
> 1 votes
Based on:

* Light Bluish Gray Plate, Modified 1 x 2 with Clip with Center Cut on Top
* Yellow Technic Bush 1/2 Smooth
* Pearl Gold Tile, Modified 1 x 2 Grille with Bottom Groove / Lip
* White Wedge 10 x 3
* Light Bluish Gray Tile, Round 1 x 1
* Black Plate 1 x 8

this should be 75248: Resistance A-Wing Starfighter.

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Tags: set-identification
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# Question
Title: From what set are these brown, white, and pink parts?
I would like to find the set these Lego bricks belong to. Browns, whites, and two 8x8 blue plates.

# Answer
This appears to be set 41153 Ariel's Royal Celebration Boat.
The 8 x 8 plates appeared a bit more blue than Light Bluish Grey, so I searched for sets with White 1 x 10 Brick and Trans Dark Pink 1 x 2 Brick w/o Tube
> 3 votes

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Tags: set-identification
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title: From which set is this bag?

text:
# Question
Title: From which set is this bag?
Which set is this bag of pieces from?

# Answer
Based on the presence of the White Plate 8x8 with cut corner, the Black Plate 10x10 with cut corner without center studs, and the engine nacelles in Dark Bluish Gray, this is set 31066 Space Shuttle Explorer.
> 6 votes

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Tags: set-identification
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title: Identify a shooter part

text:
# Question
Title: Identify a shooter part
Piece is very small looks like a shooter or something that would attach to a figure I have destiny halo Star Trek & a few misc cod & other mega pop culture figures but can’t for the life of me remember what this goes to is this even Lego/mega or did it maybe fall off one of my gundams lol

# Answer
This part is from Mega Contrux Borderlands CL4P-TP BL-U
> 4 votes

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Tags: part-identification
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# Question
Title: Replacement for the Rubber Rim of a 12V Train Motor
The 12V Train Motor Item No: 7865-1 needs a rubber train rim for traction. Unfortunately I could not find any new ones and the old rubber of used items dried out. The rim must be soft and rough, but also thin. The force of the spring for the contact studs is reduced, if the rim is too thick.

How to replace the rim with products available in Germany?

# Answer
> 1 votes
Some bicycle tubes can be used as a replacement. Depending on the model you find there might be a need to file the seam once you cut a ring from the tube.

# Answer
> 0 votes
While I don't have the original part at hand and so can't compare its physical characteristics, I suppose duct tape (cut to size) might be used depending on the target thickness, pliability and surface stickiness.

# Answer
> 0 votes
Flat square rubber rings like these are used in many types of plumbing fixtures like mixing valves used in bathtubs and showers.

In the USA these are called square rings, Bradley rings or flat rings.

Suggest that the OP look for this at a plumbing supply vendor in Germany.

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Tags: trains, wheel, replacement-parts
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# Question
Title: Is there anywhere that you can buy *custom* individual Lego-compatible bricks?
There are pieces I'd like to get, like "door rail" inside and outside corner plates, double-sided plates, 1x1 and corner masonry bricks, 1x1 panels (not a corner, more like Lego 4865), as well as pieces that aren't made in the color palette I want.

I've looked at Lepin and I see that they do have some increased color palette options for "door rail" pieces, as well as masonry bricks, but I'd like to go further (they only have 1x2 bricks/plates for each of those options) without resorting to pay $12+ a piece for items on shapeways (that would get very expensive very fast). Even $2-3 a piece wouldn't be so bad if I could just get what I want in the colors I want.

Is DIY 3D printing currently the only real option here?

# Answer
There are several ways to obtain pieces that are not in the LEGO pallette that I know of:

1. Through 3D printing at home. This has become much easier as 3D printers have seen significant improvements in resolution, precision and affordability. The challenge is to make a part that works as well as a regular LEGO brick, as that requires very tight tolerances. On the other hand, dimensions of common bricks are very easy to find in the public domain.
2. Via a 3D printing service using someone else’s design for a part. Check out Shapeways and even Etsy to see if a part has already been designed and manufactured by another fan. There used to be room on Bricklink for custom items like this, but since LEGO bought Bricklink these products have been removed from the site. Especially in the train hobby there are many individuals printing custom items such as wheels, track, connecting rods, couplers etc.
3. From a LEGO compatible brand. I would first look at reputable brands such as Mega Construx, Kre-o and the like, before going the illegal-clone route with companies like Lepin. The downside is that there are no part catalogs and trading sites for these brands (like Bricklink and Brickowl for LEGO), so you will need to look at sets and see if you can spot the piece you need. Perhaps some brands have a customer service line where you can ask questions about specific parts. Another downside is that color matching with your build can be problematic, but that likely holds for options 1&2 as well.

Note that many AFOLs consider it part of the fun of building with LEGO to use only available parts to solve a particular challenge.
> 5 votes

# Answer
3d printing works, but a lot of people steer away from it because it tends to be slow, brittle and expensive. The finish of most 3d printing is also rather rough, and it can be rather difficult to get it to match cast parts. You need to figure out which plastics you are going to print with, as they all have trade-offs.

The really good 3rd party bricks and accessories use injection molding (as does Lego) to make parts. This is more expensive and time consuming than 3d printing, but it gives better results and allows far more economy of scale. Go check out Brick Arms if you want to see what you can do with DiY injection molding.

Cutting / drilling / painting Lego - Some people do this. It might work if you are skilled with an exacto knife. Depends on your skills and goals.

Generally any 'make your own brick' solution is going to be either expensive to buy from someone else or involve you investing a lot into infrastructure to make it yourself. There isn't any silver bullet for this (yet). Lego is terrified of the technology that allows cheap fabrication of high-quality bricks, because it could mean the end of their market dominance.
> 1 votes

# Answer
I have some compatible plates with studs top and bottom in 1x1, 1x2, 1x4 and 2x2 studs bought on AliExpress. Quality is good. From same source I also have some 1x2 bricks with antistuds on top and bottom. Price also very good, with postage either very cheap or free, though delivery can take a while as they come from China - though my orders arrived before the expected date, in 1 case over a month early!
> 0 votes

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Tags: clone-brands, 3d-printing
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# Question
Title: Identify this bag: yellows, oranges and browns
I have this bag and zero idea what it’s from? Any well eyed individuals who can spot the set?

# Answer
Based on two 1x4x2 arches in Medium Nougat colour, and four rubber tyres, this is set 10704 Creative Box.
> 3 votes

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Tags: set-identification
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# Question
Title: Why does my 60198 train get lots of wheel spin?
I was running my 60198 train with the 60197 carriages attached (carriages from 60198 also on the train). My train has started to get lots of wheel spin even while on flat ground. What can I do?

# Answer
Slipping of a wheel is caused by a too low friction between the wheel and the surface. The most straightforward solution would be to reduce the mass of the carriages the locomotive has to pull, but that would be the least desirable too as you probably want to keep all currently attached carriages.

The other solution would be to increase the friction, for this you have two ways. The first is to increase the gripping forces between the wheel and the rails, for example by adding a rubber band or a thin piece of rubbery plastic (duct tape?) to the rim of the wheel. Texturing the wheel and/or the rail surface would work too, but you probably don't want to damage your pieces that way. The second way to increase friction forces is to add more mass to the locomotive itself, preferably directly above the wheels. This will increase the weight (downward acting force) pressing the wheels to the rails.

An additional, out-of-the-box option would be to convert one of the carriages into a support locomotive, thereby distributing the forces experienced by the drive wheels across more wheels.
> 10 votes

# Answer
For a locomotive counterweight, you might consider the 73090a 2x6x2 weighted brick https://www.bricklink.com/catalogItemIn.asp?P=73090a&in=S

Bricklink shows them with train sets, but I never had any of the sets they list - I think mine was from a floating boat kit: 4011 Cabin Cruiser.
> 3 votes

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Tags: trains, city
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title: Salt Lake Temple: window bordering

text:
# Question
Title: Salt Lake Temple: window bordering
I'm trying to replicate the stonework above the arched windows on the main side of the Salt lake temple.

my current approach is to use a combination of 1x2 SNOT brick to face outward 1x2 jumper plate to center cheese slope to represent the small knob at the center top of the window

I'd like to solicit suggestions on my current setup as well as suggestions about how to add the horizontal stone edging above the windows. I'm considering some combination of double slopes but they seem just a bit too big.

# Answer
> 2 votes
I suggest a combination of 1x2 plate with door rail plus 4 x 2½ x 1⅔ mudguard with arch.

# Answer
> 2 votes
Maybe part number 30586? "Plate, Modified 2 x 8 with Door Rail"

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Tags: building, design, window
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title: How heavy is the LEGO Gold Brick?

text:
# Question
Title: How heavy is the LEGO Gold Brick?
In this article, it says:

> \[The Gold Brick is\] literally made from 14-karat gold

As anyone who has held gold before knows, it is heavy. Therefore, what is the weight of this brick?

# Answer
> 22 votes
## 25.65g (0.8246 troy oz)

> **14k Solid Gold LEGO Employee Brick 2x4 Brick in Display Box**
>
> **This brick is 25.65g of 14K gold (0.8246 troy oz)**. The brick is the same size and shape as the original 2x4 LEGO brick.
>
> This incedibly rare piece was given to LEGO employees that had 25 years of employment at the Hohenwestedt, Germany factory and was also given to couple of very special business partners of LEGO of the time. It was only given out from about 1979-1981, only one or 2 per year from my understanding.
>
> This amazing brick comes in its original display box which features the LEGO logo of the time that it was given out. The box itself is plastic and has a minor amount of storage wear on it.
>
> Brick Envy - For Sale by Auction

# Answer
> 6 votes
According to this Quora post, the volume of ABS in a standard 2x4 brick is 2.4824 cubic centimeters, which is **34.13g of 14k gold** (assuming this brick is the same as standard mold).

Copied math from Quora in case link dies:

> According to BrickLink, a 2x4 LEGO brick is about 2.32g. And the median density of ABS plastic (which is what most LEGO is made out of) is around 1.07 g/cm^3. That would put the volume of plastic in a LEGO element around roughly 2.4824 cubic centimeters.

2.4824 * 13.75 g/cm^3 (avg density of 14k gold) = 34.13g.

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Tags: piece-information, weight
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# Question
Title: Is it possible to use XBox controller with PoweredUp
I have a couple of PoweredUp kits that I tweaked in the app but now, I would like to get more control on them using a physical remote.

I own an Xbox One Bluetooth controller and I thought I saw some people using them with Lego but I see nothing in the available blocks.

Did I miss something? Is it only available with Mindstorms 51515 or did I dreamt all that?

*Edit to distinguish from mentionned potential duplicate:*
Note that the root of the question is to find a way to use a compatible physical controller with PoweredUp hubs and not necessarily to find an alternative app though the use of a different app may be a solution.

# Answer
> 3 votes
And you can do that with a help of third party app called BrickController 2. Smartphone is required as a middle point connecting both hub and controller. There's a YouTube video explaining how it works.

Supported platforms:

* Android 4.3+
* iOS 8+

Supported receivers:

* SBrick - both normal and plus (output only)
* BuWizz 1
* BuWizz 2
* BuWizz 3
* Lego PowerFunctions infrared receiver on Android devices having IR emitter
* Lego Powered-Up hub
* Lego Boost Hub
* Lego Technic Hub
* Lego WeDo 2.0 Smart Hub
* Circuit Cubes

Application sources:

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Tags: powered-up, remote-control, 3rd-party
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# Question
Title: Why did Technic bricks have holes in the studs?
Lego Technic (/ Expert Builder) bricks have always had a very different design than the normal Lego brick, with peg holes lining the sides serving fairly obvious purposes, but they also have had (as long as I can remember) hollow studs on the top:

Now that these pieces are appearing in non-Technic sets I've seen them used often to hold things - they're about the same size as a minifigure's grip, so wrenches, guns, gems, and other decorative elements that need to stand are often stuck into them.

But Technic has no minifigures and features only sparse decoration. I don't recall ever seeing a Technic set that uses the holes. It seems like they would be much more difficult to mold especially as far back as Technic's introduction in the late 1970s.

So why were they introduced in Technic? (Or am I wrong, and they were *not* introduced in Technic / Expert Builder?) Did they serve a functional purpose, or were they just another visual marker to separate it from "regular" Lego during its introduction?

# Answer
From principles of molding, you want a uniform part thickness throughout if possible. This facilitates plastic flow as well as dimensional stability (you want uniform shrinkage on cooling.) Removing a divot from the underside of a stud serves this purpose in a regular brick. The Technic brick with through holes would have had a large amount of solid plastic under the stud compared to regular bricks, which could create undesirable shrinkage and warping from stress in cooling. So removing the top divot helps there.

However, if you examine a 1x16 beam from Expert Builder, you can observe a plastic channel running along the underside between studs 4 to 13 (which are injection gates; also stud 8, or 9.) The 1x8 doesn't have this. This channel would let the plastic flow away from the injection gate without turning too many corners. It's also possible LEGO used a reciprocal molding action where plastic is pressed in one gate, then another, in a rocking action, to facilitate welding of the multiple injection streams. Solid studs might lessen the effectiveness of this process, but the channel helps it. If the channel was necessary to produce a 1x16 beam back in the day, and the channel forced hollow studs, then the hollow stud style was the only way to make a 1x16 beam. The technical difficulty of making a new, longer brick (beam) may have influenced the look of the whole Expert Builder system.

That's only my theory, but you can still see the channel for yourself.

My tests also indicate the hollow stud separates from another beam more easily than a common solid stud would.

It remains possible though that they were just maximizing the usefulness of the part by making the stud hollow. Though the fun part of being an engineer is maximizing more than one property at once.

So my thought is the hollow stud came from various molding principles. Cost of plastic comes after that (and yes, if you can save a bit, you do.)

Another interesting trivia: the Technic studs were each freehand drafted in the early Expert Builder instruction booklets. I joked about reproducing this while showing some Lego employees (in 2001) what could be done with non-representational rendering, for instance a pen-and-ink renderer with random jitter.
> 29 votes

# Answer
I was very intrigued by this question. So I messed around with two LEGO Technic beams, a long one and a short one. The 'pins' at the bottom of the beams are made to fit in the hole on top of the studs.

When using the studs holes instead of the normal 'in between' way, the holes on the side of the beams are offset at mid distance. This could be very useful working with gears (I'll remember that one next time I have a complex gears ratio to create).

In the end the rules are:

1. The bottom beam must be shorter than the top beam.
2. The bottom beam cannot extend past the top beam ends.

The following picture shows why rule number 2 is important. The end of the top beam and the studs of the bottom beam interfere.
> 18 votes

# Answer
In my opinion, you don't need to look further than plastic quantity, and thus cost.

Take a normal brick or plate (easier) and look inside it. You'll notice that each stud is hollow, but from below. Why? Simply because there's no need to have it full with material as it serves no purpose. It's easy to make the mould that way, it doesn't remove any functionality of the brick, everybody is happy.

Now take a Technic beam and look at it from under. The Technic holes make it way more difficult to have a mould which has cavities under the studs. So the easy solution is to have the cavity in the stud itself, which has the added benefit of adding functionality to the stud itself. Also, I suspect that the sturdiness of a Technic beam is better if the upper side is full.

Note it's just speculation; but most of the times you need to analyze a part with the eyes of a LEGO producer (use as less plastic as possible), and of a designer (have a part which fits with as many other parts as possible). Nowadays, it's likely they would use hollow studs more and more, and I wouldn't be surprised if they end up on regular bricks some day — but that's going to take a while as there is a third factor in play: brand recognition. regular LEGO bricks have full studs, with the LEGO engraving, and that's not seomthing which LEGO will easily accept to replace.
> 14 votes

# Answer
Most 1×2 (and longer) plates and bricks have a pin at the bottom right in the middle of studs that perfectly fits this hole.

Connecting this way gives you half-stud shift.
> 14 votes

# Answer
After getting a great answer to my question: When did Lego decide that it was okay to put a stud into a technic hole? and looking at the pdf slides linked there: http://bramlambrecht.com/tmp/jamieberard-brickstress-bf06.pdf, it's stated in one of the slides that the words "LEGO" on the top of the brick adds a little height, .14mm to be exact, to the brick. This extra height interferes with the Lego dimensions for Technic elements. So the hole'd studs was likely a way to still have the stud, but shave off that top .14mm.
> 6 votes

# Answer
In answer to part of your question, Expert Builder sets were not the first appearance of the hollow stud. I believe the old-style windows were the first, starting in the mid 60s:

The reason for the hollow studs here seems to be related to the exposed underside of the stud face. LEGO seems to have wanted to have the inner frame of the window smooth rather than have the divots that regular studs would create. So they shifted the divots to the upper surface where they would be hidden in most uses.

There is another functional reason some modern pieces have hollow studs: child safety. Around the same time the Expert Builder sets were introduced, LEGO started using hollow studs on small cylindrical pieces like 1x1 round bricks and cones that went clear through the brick. This was to provide an air hole should one (or more) of them be stuffed in a nostril or ear canal, or be swallowed or inhaled. In some cases, like with 2x2 round plates and bricks, LEGO uses a through axle hole for the same purpose.
> 4 votes

# Answer
The 1x2 plate with 1 knob (Design ID 3794) has the same design for it's top stud - I assume for the same reason Joubarc gives - you can't create a hollow stud from underneath as the peg's in the way.

Peeron.com
> 3 votes

# Answer
Hollow studs fit the bars on the underside of 1×x bricks. The same hollow studs are found on Lego windows and Minitalia pieces (Lego made in Italy), also 1×1 with holder and 1×2 tile with 1 stud, 1×2×5, 1×2×3 slope.

Other brands, such as Montini and Tente have hollow studs and unknown on 1×1 plate. So maybe should ask 'why aren't studs hollow on all Lego pieces?' So Technic beams were not the first.
> 0 votes

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Tags: technic, piece-information
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title: Challenge: Specialized Palm Build

text:
# Question
Title: Challenge: Specialized Palm Build
I'm trying to design a hand for a MOC using the (not so) new Mixels ball joints, in line with a concept that I've had rattling around in my head for a while. The current palm design I'm trying uses the Technic Gear, 24 Tooth with four of the Pin with Towball in its four holes, on which the longer Mixels ball joint cups are attached. The result is shown in the picture below.

This hand works well for the most part, but the ball joint cups tend to run into each other when splayed out as pictured. This makes poseability a good deal harder in terms of fine finger movements (gripping seems, thankfully, unaffected). There is also the issue of this hand being two studs thick, due to the towball pins being positioned outward from the palm. I've looked around for alternate builds or pieces that could improve this design, but nothing quite fits. For instance, the Compact Steering Arm is almost perfect, but is missing a fourth ball joint. The old Helicopter Rotor Holder is very nearly too wide for the design, and doesn't seem to allow friction in its connection.

My challenge is this: design a palm with towball attachments for four fingers, either at the four compass points from the center or capable of being placed in these positions, and a central attachment point with either an axle hole to prevent turning at all or a pin hole that can accept a friction-creating pin. The towballs should be far enough apart that the ball joint cups don't run into each other. The towballs must also be no more than two studs apart (measured from the center between towballs on the same edge of the hand), or else the finger design I'm using will not properly close across the palm. A one-stud thickness would also be a plus, but might not be possible with the previous specifications.

Thanks to Caleb Woodman for pioneering the challenge tag mere minutes before I came to the site to ask this. I probably would have spent a lot longer searching the tag list if I hadn't seen that on the front page.

# Answer
> 4 votes
The Nexo Knights sets have a new piece, the Bar 1L with Towball, which might work for putting a bunch of mixel joints in a small space:

Also, if you could get your hands on the maxifig hand, it's great for connecting to mixel joints. It's a 1x1 round tile with a hole in the stud and a ball on the side:

Either of these attached to the brick with 4 studs on the side could work.

# Answer
> 3 votes
After some experimenting, here is another solution that might fit your needs. It consists of 3 alternatives:

Required:

I am not sure on the legality of Builds 1&2 as the technic pins are sitting on the pneumatic T-piece instead of being inserted in a hole, but I know they have a strong grip.

**Build 1:** This way the height of the palm is 1 brick - but the fingers are about 4 studs apart. You might be able to get that a bit closer by replacing the pneumatic T-piece with either 60849 Minifig, Utensil Hose Nozzle Elaborate or the older 194 Minifig, Utensil Hose Nozzle Simple.

**Build 2:** Compacter but with more room for movement than your current solution, but the height is 3 bricks:

**Build 3:** Similar to your original solution, but allows for better flexibility of the fingers, at the cost of a 2 brick height - and the towball pin is not fully locked in the headlight brick, there is a little play. This can be solved by sticking a 33183 Carrot Top through the bottom hole of the headlight brick for each brick:

---

EDIT: Here is a fourth alternative - this one might fit the bill - the towballs sit a little further apart than on your original 24-tooth gear solution, so no rubbing. Still 2 bricks high though.

**Build 4**:

# Answer
> 2 votes
Since you do not give a desired size of the palm, I'd like to propose the following solution, consisting of 1x 6222 - Brick, Round 4 x 4 with 4 Side Pin Holes and Center Axle Hole and 4x 6628 - Technic, Pin with Friction Ridges Lengthwise and Towball, arranged like so:

You might need to work on the size of the fingers to make this work with "grip" - but it meets your challenge criteria.

There is also part x872 - Technic, Steering Arm with 4 Ball Joints which would be more compact, however, this part is extremely hard to find (there are no sellers on BrickLink currently).

# Answer
> 1 votes
Have you considered Nanoblocks? Their ball & sockets stay in position when Lego tow ball & sockets are loose. Stagasorus includes a few.

Attach to Lego, 10% 40% possible with 2×2 under.

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Tags: design, piece-usage, challenge
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# Question
Title: How can I identify a set based on one or more original sealed bags?
I have recently come into possession of one or more sets in the form of factory-sealed individual bags made of transparent plastic, containing various LEGO elements. There is neither box nor any instruction booklets. I have checked the bags and the parts contained within them are definitely genuine LEGO pieces (all non-hollow studs have the LEGO logo relief). How could I determine which set(s) I own? The bags have different texts, numbers and codes printed on them.

# Answer
First of all, congratulations on your new set(s)!

Second, let's just ignore anything printed on the plastic foil itself, as the numbers and codes are independent of the actual contents of the bags - those markings only serve to identify the plastic bag as a packaging material, not the filled bag as part of a set.

Now then, onto the contents of the bags. Take a bag and lay it flat on a surface - you want to see as much of the parts inside as possible without them obscuring each other.

Now try to identify the most unusual pieces, that are most likely to be unique to the set you have. Anything large, transparent, printed or having a complex form is a good starting point; but be prepared to backtrack if needed. Knowledge of the most common LEGO pieces and the most popular colours is a great help in this phase, but persistence can stand in for it just as well.

To identify the exact piece, visit Bricklink's part catalogue, where you can find all LEGO elements ever officially released (and a few more that were never sold!) in neat categories. This is just like a library, where you'll eventually find what you're looking for, but might need to search in a few different sections. Having the dimensions of the part is usually a good idea, as most parts have that in their name. Once you've identified a part in your bag, try to match its colour as well from the list of "Known Colors" under the tab "Color Info". Then count how many times can you see this exact piece in the bag. Note the following for each identified part: 1) **Item number**, 2) **Colour**, 3) **Amount** in your bag.

For example, take a look at this bag:

The key identifiable parts here were:

| \# on pic | Piece name | Piece number | Colour | Amount |
| --- | --- | --- | --- | --- |
| 1 | Plate 6 x 6 | 3958 | Black | 1 |
| 2 | Brick, Round 2 x 2 with Axle Hole | 3941 | Yellow | 2 |
| 3 | Brick, Modified 1 x 2 x 2/3 with Studs on Sides | 4595 | Black | 1 |
| 4 | Brick, Modified 1 x 1 with Headlight | 4070 | Red | 8+ |

After you have done the above step at least three times, you're ready for the next step. Now open Bricklink's "Appears in" page, of the multi-part variety. Here you can enter the previously found part numbers, colours, and how many times that part appeared in your bag. When done, click the "View Appearance" button.

You'll get either a screen like this:

or one like this:

In the first case, the combination you've entered is not found in the database - most probably due to a mistake in the entered data. Many parts have extremely similar variants, some colours are really easy to confuse with each other and sometimes counting parts is not so straightforward either, so don't get discouraged just now. Try some other combination of parts you've found, maybe attempt to identify another part from the bag and plug that into the form.

In the second case your set might just be among those candidates displayed (but beware of false positives caused by misidentified parts!), so let's find which one. Open the "Inv"entory of the first set (the purple link in the picture) and start matching the parts in your bag to those of the candidate set. If you find a part in your bag that is not included in the set: you've successfully eliminated that candidate - return to the list and open the second "Inv"entory.

If all parts of the bag are found in the inventory, you're (partially) done. Why partially? Because if there are more candidate sets, they might be matches as well! So let's check them too. Note however, that most sets contain many bags which are seldom separated from each other, so check the other bags to help narrow your list of potential candidates.

After you've definitely found your set, it's time to remove from your pile of bags all that belong to this one. With the set inventory in front of you, this will be a breeze compared to the beginning as you just started to look for uncommon pieces and counted studs.

If there are bags that don't belong to that set, put them to the side for another iteration of this same process.

Having collected all bags in your possession to this set, you can fetch the instructions by scrolling to the bottom of the set page on Bricklink, and clicking through to Brickset under "Other Databases:" (or open Brickset and find your set there based on the set number). There you'll find the instruction manual for most sets.

Have fun and feel free to open a new question if you have problems or questions with any of the above steps!
> 17 votes

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Tags: set-identification
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# Question
Title: What materials have LEGO Bricks been made from?
Inspired by this comment, I wonder, what materials have LEGO Bricks been made out of, apart from plastic? Can these also interlock with other blocks?

###### **Please Note**: I am only asking about *bricks*, and thusly not any components such as motors.

# Answer
Ignoring the different kinds of plastic that LEGO have used for their bricks over the years (formerly CA, HIPS, Bakelite, PC - currently (M)ABS - and a range of different plastic types for parts that need different properties), I can't think of any bricks that came with LEGO sets that fit your criteria.

If we expand the scope to the gear category (things like key chains, clothing, storage solutions, etc. with the LEGO brand), there are a few that seem to fit your criteria. The ones I can think of :

I have none of these, so can't attest to their ability to interlock with regular bricks, nor to their clutch power. I also haven't been able to find information on this (the former two are very rare).
> 3 votes

# Answer
As noted in this related question, part 73020b "2x6x2 weighted brick" contains a chunk of (what seems to be) galvanized iron.
> 2 votes

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Tags: connections
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# Question
Title: Set identification: Ninjago style dragon
Can someone identify the set containing this (part of probably) creature?

Found it in a box at a thrift sale, along with 2 ninjago motos and snake-headed minifigs, all of this may or may not be in the same set.

# Answer
This looks like (part of) 70674-1 Fire Fang which is indeed a Ninjago set.

I identified this the hard way, using Dark Tan Barb/Claw/Horn/Tooth Small which looked fairly unique but is actually in many sets.
> 5 votes

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Tags: set-identification, ninjago
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# Question
Title: I have this bag of mostly reds with light grays
I have this bag of mostly reds with light grays. Some blues, yellows, and orange. What set would these legos belong to?

# Answer
> 2 votes
A search for sets containing 2 4x10 dark red plates and a 2x2 round brick with grille profile returns just one hit: set 21154.

See also How can I identify a set based on one or more original sealed bags?

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Tags: set-identification
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# Question
Title: Selling a physical build from purchased instructions?
I have been trying to find information on this subject including contacting designers. I have heard as long as you don’t include the instructions in your sale, all is fine as that is the intellectual property. But I have also seen instructions barring against selling of the physical model as well. Most information I find is on the piracy of the instructions themselves. I am looking for info on the selling of the actual build. Like, what if I were to purchase instructions of a modular building and after I buy all the parts and build it I see that I don’t like the look of it in my city. Could I not sell the model to someone else? I believe to understand the intellectual property laws but what about fair use? Thanks for any help.

# Answer
I'm not a lawyer, so this is purely from a layman's understanding.

You don't say what jurisdiction you're in, so I don't know if what I'm saying applies to you. But in the USA, the First Sale Doctrine means that you have the right to sell your copy of any copyrighted material that you have bought. If, for example, you had bought a physical instruction booklet, you would (in the USA) be within your rights to sell that booklet to a third party, with or without the bricks needed to build the model.

If you received the instructions as an electronic copy, you would still be within your rights to do this, but would need to ensure (and ideally find a way to prove) that you had transferred all copies of the instructions and not kept one back for yourself.

I don't know if there is any precedent for the scenario where someone sells the model (built) and keeps the instructions. Intuitively, I suspect this might violate copyright, as the completed model could be considered a derived work of the copyrighted instructions; either could be used to make more identical models.
> 2 votes

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Tags: shopping, moc, ebay
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title: How is this setup created?

text:
# Question
Title: How is this setup created?
From https://www.newelementary.com/2018/10/lego-35787-tile-modified-2x2-triangular-45-cut.html midpage there is this setup:  Can anyone provide more details how the parts are connected? Preferably so it could be recreated in bricklink studio.

# Answer
> 4 votes
I have been doing a few experiments with part 65578 "Bar 1L with Ahgled Hollow Stud. Using one of them at a distance of four plates from one of the triangular tiles (using SNOT 180° if needed) would work:

Note how the fit is not perfect - in the setup displayed above, the roadsign has one side touching the top tile, but the fit to the side tiles is angled. And if you look closely to the reference image, you'll notice that the perfectly-fitted side is the right-sided tile.

Replicating the whole original setup hints that the bar with stud may be held just by gravity, with no actual connection and no clutch at all:

Note how the stud from the bar fits snugly along the tiles.

However, I suspect that this is not the technique used. Note how, in the reference photograph, we can see through the gap between the roadsign and the top triangular tile; in my CAD design the bar with stud blocks that gap. There might be some other part (a minifig accessory, perhaps?) in play.

I suggest experimenting with a sausage instead. Its curvature should allow to tweak the angle of the roadsign, and so would make an even better fit.

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Tags: building, bricklink-studio
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title: Help identifying a brick

text:
# Question
Title: Help identifying a brick
Found this part a Lego event and would like to get some but can’t seem to locate. I believe it’s from a technic set.

# Answer
> 6 votes
this is a CATAPULT ARM 1X4 (88289) in black

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Tags: part-identification
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# Question
Title: Technique for connecting a tile vertically next to a brick
I'm trying to create this effect, where a 1x1 half-circle tile seems to 'stick out of' a 2x2 brick at 90 degrees:

This is easily achieved with a 1x1 tile with light attachment, as seen here from the back:

However, that particular piece is quite expensive in my chosen color (either orange or dark orange).

I've tried using a technic axle-and-pin connector, but it looks very bulky and the pin itself is also not available in (dark) orange:

I've also tried various brackets in different configurations, but since they're all square, the edges stick out from under the half-circle tile.

Are there other ways to achieve the same, or a similar looking effect?

# Answer
Some ideas given the color constraints (all used parts are available in Orange, except those not visible). Perhaps none are very compelling, but they might point you in a different direction.

If you're not afraid of stressing bricks a bit (only during (dis)assembly - when assembled, there's no stress), using Hinge Plate 1 x 2 Locking with 2 Fingers on Side and 7 Teeth (50340) :

**This next one doesn't actually work as pointed out in comments - the rod attached to the hand is too thin to stay put. Leaving it here in case someone knows of a trick to make it work anyway.** When it's acceptable that the tile is slightly off angle, using Hand (983) and Technic, Brick 1 x 1 with Axle Hole (73230) :

Using Slope, Curved 1 x 1 x 2/3 Double (49307) instead of the tile :

And finally, a very rough approximation of the shape using Hinge Plate 1 x 2 Locking with 1 Finger on Side (44567) (assuming your requirements are quite flexible) :
> 12 votes

# Answer
Perhaps too straightforward: placing tiles between studs is a legal technique (so are plates by the way if the studs where you insert the plate between are hollow):
> 11 votes

# Answer
I'll suggest using a 1x1 plate with clip, recessed half a stud by means of a jumper plate:

I haven't tested this physically, but I assume that the clip will be under stress since (in this assembly) the round tile won't fit through the entire clip.

---

If you're OK with using *dark* orange, then you can use 1x2 plate round with some SNOT to achieve the effect:
> 7 votes

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Tags: building, connections
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# Question
Title: Can you help identify what set these parts belong to?
Can you help identify what set these parts belong to? There is two blue octagonal parts, two red parts, dark grays, blacks and bananas.

# Answer
> 3 votes
Those Plate, Modified 10 x 10 Octagonal with 6 x 6 Open Center only come in dark azure (and doesn't even exist in any other bluish colour) in two sets; only one of them also has Yellow Banana, and that is the set that Heartspring already has pointed at in a comment: namely Gorzan's Gorilla Striker.

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Tags: set-identification
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# Question
Title: How can I easily take apart stacks of 4x4 plates?
Earlier this week I bought roughly 200 4x4 plates from the Pick A Brick wall at my favorite LEGO store. Greed got the better of me, and to fill up my PAB cups as much as possible, I stacked the plates tightly onto each other:

Now that I'm back home, **how do I take these apart easily without breaking my nails?** I don't get enough leverage using a LEGO brick separator, and using the flat end to pry apart plates is damaging the separator a lot.

# Answer
> 5 votes
Pop them apart with a pocket knife (don't cut yourself!) should work just fine. A note for next time, put them together with one row of each piece exposed to make it easier for you.

# Answer
> 3 votes
4x4 plates might be the worst-case scenario - larger plates flex a lot and so can be twisted apart; smaller plates can't bind as much because the have fewer studs. I had this problem, and it required multiple brick separators - typically two on top, two on the bottom, and one or two along the edges to try to pry the plates apart. Next time, you should consider off-setting your plates by one stud so that they are not fully attached.

# Answer
> 3 votes
Try using a pair (or possibly three) longer 4-wide plates (4x8, 4x10), attaching them on a offset- gripping 12 of the 16 studs of your 4x4's. The longer plates should give your hand and arm something decent to hold on to, and you may be able to get some twisting and prying action because of the good grip provided by new elements, and the fact that you won't need to be pressing down on the whole stack.

# Answer
> 2 votes
Dental floss works quite well.

# Answer
> 2 votes
What I often do is place the stack on the large flat base plate or bigger plate of some size, and use the stud end of the separator to pull them off one at a time. That often helps, when the stack is firmly stuck to a larger plate. You can also use the underside of the flat part of the separator, I don't know why, but that works for me sometimes better than the top-side of the flat part of the separator. Also, when your separator gets too damaged, you can use sandpaper to smoothen it out again.

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Tags: brick-separator
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# Question
Title: Please help identify this mech robot set
This is some kind of mech robot. I guess it is coming from some Japanese story as on its left leg it has some Japanese writing.

I would love to rebuild/complete it but can't figure out what it is.

Thank you!

# Answer
That's part of Thunder Raider (70723), a Ninjago set from 2014 :
> 5 votes

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Tags: set-identification
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# Question
Title: Which clone brand with a red logo and an 'M' is this?
While in Poland, I have recently come across this Lego-compatible brand:

What is the name of this clone brand, with the 'M' logo? A Google Images search did not yield any useful hints.

As far as I could figure out, the Chinese text on the box just indicates the name of the model, and that it's a building brick toy (obviously), manufactured by a company in Shantou.

# Answer
After some Googling, it seems as the name is MG.

I found a page which lists it as a brand: https://www.lazada.co.id/mg/?spm=a2o4j.pdp\_revamp.0.0.705f736fGESNgD&type=brand

I don't even know what language it is, so didn't spend much time on the site, but further Googling of MG yields more similar results.

Looking at the box it says "MG936D". This seems to be the specific ID for this set, while "MG936" is the identifier for all their "Dinosaur World" sets. They have other knock-off series where there is another three digit identifier.

I'm not a fan of knock-off products, but I like the consistency they seem to apply here.
> 3 votes

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Tags: clone-brands
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# Question
Title: Is the LEGO train motor 88011 waterproof?
My son has been building a LEGO RC boat and has added the motor (part 88011) from this LEGO City Train Set to drive the turbines. He's pretty keen to try it out on water but I imagine the motor is probably not waterproof. I couldn't find any information on whether this part could be used underwater online so promised him I'd ask the experts here for advice.

Additionally, I'd also like to know if anyone can attest to the waterproofness of the hub with the batteries from the same set (I think it's this part here). While he has stashed that away on the boat above the waterline, it might still get wet if things don't go as planned.

# Answer
LEGO's electric or electronic parts are usually not waterproof, with a small subset that was explicitly designed for such use in a few nautical-themed sets between 2004 and 2007. These motors feature no open contacts, integrated battery holders and gaskets along any seams to provide water sealing.

The components you ask about have open contacts, no sealing - and even if they did, the radio waves required to operate them underwater would be greatly diminished by the physical properties of water to the point of unusability at even minor depths. They were not designed to be used in any kind of wet environment, including fog or rain. Surprisingly, I haven't found any kind of official warning to this effect in the building instructions, but if you'd like, I can ask a representative of LEGO directly.

If you're really intent on using the motors near or in water, you'll need to either build a structure which guarantees that the batteries and motors will always stay above the water line (including any waves and spray) even if the boat rolls or capsizes; or build some kind of waterproof enclosure for them. Beware though, neither of these is an easy endeavour and any mistakes during design, building or operation could easily ruin both the hub and the motor. But there have been people who managed to achieve success with both of these approaches, so these are definitely doable - just with significant planning, engineering and tinkering and at no small risk.
> 8 votes

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Tags: piece-information, motor, powered-up, piece-usage, water
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# Question
Title: Are there any existing (or upcoming) aftermarket PoweredUp hubs?
I bought the Mindstorms v4 / advanced hub (in set 51515). It's a good set, and the Hub has some great features - notably a rechargeable battery, the ability to run "live" off of USB power, and a full 6 ports (the minimum, IMHO; covers most working equipment such as fully-motorized excavators, etc.)

However, the battery lacks capacity, and the drive voltage of the motors is underwhelming. USB-C PD is also lacking, and would be a huge feature as it would allow 9v power from cheap COTS battery packs.

I went searching for a BuWizz/sBrick/etc. type replacement; I can't find anything except for a current Kickstarter (no link, as I backed it and and don't want any perceived advertising here - but it does look interesting, supports Arduino, check it out :) )

Are there any aftermarket hubs in the works you're aware of? Any supporting info such as ETA or experience of the creators, etc., would be helpful.

I'm starting to think I may need to DIY; the PUP connectors themselves are available only from China (are there any patent concerns?), but are cheap enough. It looks like the specs and i2c protocol bits are all reasonably well documented. IMHO, an ideal setup would:

* support a higher drive voltage for the motors.
    + the onboard https://www.onsemi.com/pub/Collateral/LB1836M-D.PDF supports 10.5 abs max.
    + even a consistent 9V would be a HUGE improvement; a 3s1p lithium ion pack, plus a 90%+ efficient buck converter board to ~9V seems feasible?
    + side benefit of 9V is it could also be driven from a USB-C PD board set to 9V (although muxing this with the battery isn't trivial or supported by any of the cheap boards I can find from Aliexpress or US hobby sites.
* support lots of channels; 8 or more? Most microcontrollers or SBCs should be able to drive at least this many channels of motor controllers.

# Answer
BuWizz has announced the BuWizz 3.0 Pro which has Powered Up compatible ports.

The product page says:

> Expected Delivery: End of March 2021
> 3 votes

# Answer
Raspberry Pi produce the "Build HAT" which is an interface board for the Raspberry Pi and it works with Powered Up sensors and motors.
> 2 votes

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Tags: mindstorms, moc, powered-up, 3rd-party, battery
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title: Alternative to LEGO CONTROL+ app

text:
# Question
Title: Alternative to LEGO CONTROL+ app
My son just received the Liebherr R 9800 excavator 42100 LEGO set.

It would seem the Control+ app that is recommended for it simply won't work. It doesn't even connect to the blocks.

**What are the available alternatives?** And if this SE allows it, any recommendation/comparison between them would be greatly appreciated.

We're just looking to control each motor individually, no fancy achievement, scenarios, etc... We'll be able to compile from source, if needed, on MacOS or Ubuntu. We'll be able to run Android and IOS apps too (although I'd prefer to stick with official app stores), but the house has no Microsoft OSes available.

Edit: apparently control+ Android Pixel 3 simply doesn't work, but the app works on IOS. In my case, using BrickController 2 on Android solved the issue.

# Answer
There is an alternative app called BrickController 2. This open source software is available for both Android as well as iOS. This application is actively developed and its maintainer can be reached on Eurobricks forums. You can also report and discuss any issues there.

The application is universal compared with solution offered by LEGO since one device allows you to control more than just LEGO Power-UP electronics. The following receivers are supported, by the time of this answer:

* LEGO Powered-Up HUB
* LEGO Boost HUB
* LEGO Technic HUB
* LEGO Power Function infrared receiver (on devices having infrared emitter)
* SBrick and SBrick Plus (3rd party devices)
* BuWizz 1 and 2 (3rd party devices)
> 13 votes

# Answer
There is a free app called buwizz. It is a great alternative that gives more freedom, and works on Android.
> 6 votes

# Answer
I have started working on a C# SDK to control compatible Control+ / Powered Up hubs.

See: https://vouzamo.wordpress.com/2020/04/06/c-sdk-for-lego-bluetooth-le-hubs/ for more information.
> 1 votes

# Answer
Have you tried to use the PoweredUp App (also by Lego)? It gives full control over motors and programmation. It is like the advanced mode of Control+.

Here is a video by RacingBrick showing most capabilities even though since the last update, unfortunately, most programming blocks have new UI. Don't forget to enable the Advanced Palette if you want the full features.

https://www.youtube.com/watch?v=a4gWPey2sBE
> 0 votes

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Tags: technic, remote-control, powered-up, control-plus
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title: Identify 2x newish pieces please!

text:
# Question
Title: Identify 2x newish pieces please!
I've got two pieces to identify, and I don't know how to look these ones up on Bricklink so am looking for help here:

* Light Bluish Grey 1x4 brick with a slot that a 2x2 round tile fits into
* Flat Silver round grenade-looking piece with bar

# Answer
Searching for "1 x 4 shooter" yields part 16968 "Projectile Launcher, 1 x 4 with Inside Clips (Disk Shooter)".

Paintstakingly looking through the list of all Flat Silver parts ultimately yielded part 40598c "Minifigure, Weapon Larger Blunt Grenade Tip".

(Finally, looking for sets which contain both parts yielded set 76150)
> 6 votes

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Tags: part-identification
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# Question
Title: Help with differentiating old gray and yellowed pieces
Hi everyone, I'm having trouble deciding if those pieces are yellowed, old shades of gray, or just natural differences in color because of different LEGO batches. I'm skeptical of old gray because these pieces are from sets from around 2011-2015. Any help with this would be greatly appreciated.

P.S. I soaked them in hydrogen peroxide in full sunlight for a couple of hours but there has been little to no effect.

# Answer
> 1 votes
To me the first picture seems to contain dark bluish gray pieces while the other two look like light bluish gray. Especially since the Wheel 18mm D. x 14mm with Pin Hole, Fake Bolts and Shallow Spokes was never officially released in any of the old grays, just Light Bluish Gray (and a bunch of other colors that are impossible to mistake for old gray).

Additionally, all the plates here have been released in a lot more sets as their "bluish" versions than in the old "light/dark gray" colors, so unless your collection is known to be composed of older sets, statistically it's much more probable that a random sampling of these pieces would be the new, "bluish" versions. For example take a look at the *Plate 4 x 4*: it was released in more sets as light bluish gray, as in both old color variants together, and in even more sets as dark bluish gray. The number of pieces in those sets is even more extremely skewed.

| Color | \# of sets | \# of pieces |
| --- | --- | --- |
| Dark Gray | 29 | 78 |
| Light Gray | 81 | 129 |
| Dark Bluish Gray | 438 | 946 |
| Light Bluish Gray | 349 | 764 |

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Tags: part-identification, colour, quality
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title: Tan castle? or whatever

text:
# Question
Title: Tan castle? or whatever
Bought a batch with quite a few tan bricks,

* 4 quarter circle panel
* 4 quarter circle brick
* 2 tower panel like 1/2 of 8-sided with arch window
* arches in 4 sizes
* slope 2:1, 3:1 & invert 1:1 (×1 & ×2)
* 1×1×1&5
* 1×2×1&5

# Answer
I made some guesses as to what parts you are describing. I particularly did not understand your description of the slopes. Luckily the other parts are enough to uniquely identify the set.

There are six sets that use 30246 - Tan Panel 3 x 4 x 6 Turret Wall with Window.

While some of them also use the 30562 - Tan Cylinder Quarter 4 x 4 x 6,

only one uses both it and 48092 - Tan Brick, Round Corner 4 x 4 Macaroni Wide with 3 Studs.

That set being:

**4757-1 - Hogwarts Castle (2nd Edition)**
> 7 votes

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Tags: set-identification
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# Question
Title: My EV3 program will not run despite clicking on the program from the brick
This is a new EV3 Education Core Set. I have made a simple move forward command using the Lego Mindstorm EV3 Students Edition and downloaded it into the EV3 brick. However when I press the program in the brick, nothing happens, not even a loading screen. When connected to the computer and the program is there, I just can't run it. How do I troubleshoot this?

# Answer
> 2 votes
You said that you did a simple move forward command. Is that the only thing you did? If so, then basically the program sees your "move forwards" and starts up the motors. It moves on to the next brick- but that's the end. If there are no bricks left, it terminates the program (stopping everything: including the motors). This all happens within milliseconds, so the motor doesn't even have a chance to start moving, and to you, it appears as if the program didn't do anything.

td;lr to fix this just make your program wait before ending. Like, "wait until \<touch sensor \[pressed\]\>" or "wait (5) seconds".

# Answer
> -1 votes
I don't own the EV3, so unfortunately I can't help you with first-hand experience. Here is a link to the LEGO site containing videos with everything you should need to know to get started.

Getting Started with LEGO® MINDSTORMS® Education EV3

Based on my experience with Mindstorms NXT, if you are sure the program is done correctly then make sure you chose the correct ports that your motors are plugged into.

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Tags: ev3
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title: Rotating and elevating platform

text:
# Question
Title: Rotating and elevating platform
I want to build a platform that can be raised and lowered but also rotate at the same time. Tried scissors and linear actuator, etc. and other techniques but cannot figure out a way to raise and rotate at the same time.

# Answer
They are many ways for a "Lift and Rotate" platform.

The easiest way to do this is by using the rotary part 73763 (Technic, Gear Worm Screw 6L) and the stationary part 73764 (its housing), and a Technic Small Linear Actuator on the bottom that stays in the fixed rotation.

The second alternative is to use gear racks and bevel gears for the same effect.
> -1 votes

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Tags: technic
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# Question
Title: What is this 2x4 brick with a clear bottom, a small hole at each end and a 6 brick high pole?
It is a 2x4 with a clear bottom a small hole at each end and it is smooth on top with a 6 high pole coming out.

The brick has no numbers on it so I'm not sure what it is I have tried searching for it however I can't find it if anyone knows what set this is from that would be great.

# Answer
> 5 votes
It looks like it's 799c800:

This part was used to implement a simple "hand of god" steering system on a bunch of sets in the 70s.

# Answer
> 0 votes
Steering column complete, fire engine, tipping lorry, low loader that came with crane, also on its own 'Lego spares' at Wrexham. Look for 4 & 5 wide plate with a hole, plate with part 2 studs wide with hole, 4-stud wheels (or 1 stud & spokes) & a 1×2 with the word 'LEGO' on side. 1 of mine broken, = on fire engine. So I'm after 1.

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Tags: part-identification
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title: 2×2 & 2×3 that join by ends

text:
# Question
Title: 2×2 & 2×3 that join by ends
Bought a batch & found these, what are they called? What are their uses?

# Answer
> 7 votes
These are various modified Technic Bricks with "Joint Ball Half" and "Rotation Joint Socket" features as they are called on Bricklink. Technic Rotation Joint Ball Loop with Two Perpendicular Pins with Friction are the connectors for this type of elements. Although there are more ways to attach them. These elements have been used in large number of sets, originally coming in brick-built figures like Danju (8770):

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Tags: part-identification
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# Question
Title: Trying to find the name of a LEGO set from a sealed bag
I have got a couple of bags which I think are for the same set.

# Answer
This is from The Skeleton Dungeon (21189) set.

Identified by unique combination of:
> 0 votes

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Tags: set-identification
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# Question
Title: Compare part lists between Stud.io models?
I've created a MOC using Stud.io, bought the pieces and built it. Since it was unstable I've changed the model in Stud.io, and now I would like to buy just the pieces I've added. I could compare both version of the model manually to get the differences, but that would be somewhat cumbersome and error prone, so I'm wondering if there is some tool to compare two models, or two parts lists?

I'm thinking about something that could for example take two BrickLink XML files, and produces a new XML containing only the parts (and amount) not present in the older version.

# Answer
Since there doesn't seem to be a tool, I've written my own one. In case anyone else want to use it, check it out here: https://github.com/ChrZae/bricklink-xml-diff

Take care tho, it can only really process the XML generated by Stud.io, the XML-format itself has more fields which I didn't care about (also no guarantees it will always work correctly).
> 8 votes

# Answer
I would use the winmerge tool:

http://winmerge.org/downloads/

XML files are text files. You can compare two text files with Winmerge and extract the differences... some manual labor would be involved if the same part is present in both lists but with different amounts, but I would expect this to be all rather straight forward...
> 3 votes

# Answer
I usually use Rebrickable to compare whatever I need.

First, you need to create two custom lists (My LEGO \> My Custom Lists). Import tool supports "BrickLink Stud.IO files" so no conversion is required.

Once you got your lists sorted you need to compare them using "Compare sets" feature (Sets \> Compare Sets). While the name suggest only sets could be compared in reality functionality is broader - you can compare custom lists as well. You will then be presented with the result, where "unique" parts are the ones that does not exist in compared model. You can also export this list for further use.
> 1 votes

# Answer
A little bit late to the party but I made this notebook to compare your brick: https://github.com/mhoangvslev/bricklink\_tool\_suites/blob/main/Bricklink\_Compare\_Parts.ipynb

I simply use 2 part lists downloaded from Bricklink.

Feel free to modify it to your need.
> 0 votes

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Tags: software, tools, bricklink-studio
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# Question
Title: How to buy a lot of 65803 Technic plates for a mosaic project?
I would like to make a pixel-art mosaic and found out the existence of part 65803 for building the base board: https://www.bricklink.com/v2/catalog/catalogitem.page?P=65803#T=C

Alternately, there is a chinese clone available under the brand YNYNOO: https://www.aliexpress.com/item/1005004221907158.html

My consideration to get a third-party part is because buying the genuine LEGO versions in bulk seems difficult. There are lots of suppliers on BrickLink, each one with a small inventory.

Is there any knowledge about the relative quality of the third-party equivalent? I guess it may be a tad lower than the genuine part, but the supplier is able to sell enough for my needs in one go.

I am looking for a solution with the least mental surcharge ( = reducing having to deal with a lot of suppliers) to buy the parts, and ideally not too expensive in shipping fees.

# Answer
Available as a Bestseller at LEGO Pick-and-Build. That means you can order a maximum of 999. Hopefully that is enough for your purposes.

https://www.lego.com/en-us/pick-and-build/pick-a-brick?query=65803
> 6 votes

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Tags: shopping, 3rd-party, mosaic
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# Question
Title: How can I verify authenticity of (R2-Q5) head/dome
This seems to be 553pb003 part. I am trying to find out where the LEGO logo is printed on this 2x2 dome piece given it is the older style dome with the semi-open top stud, meaning there is no LEGO logo on the stud. Does anyone know where should I look for LEGO logo on this piece? If not - is there any way I can verify it as authentic?

# Answer
> 1 votes
I have part 553pb003 from the sw0213 minifigure (Astromech Droid, R2-Q5) but the one I have has a blocked stud (see photo). I have 2 other astromechs: R7-D4 (sw0119) and R2-Q2 (sw0303) which have similar blocked open studs to yours. There are a lot of markings underneath it on the inside and those include both the Lego(c) sign and part number as well as other numbers. I tried my best to take photos. At least for these markings are evident.

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Tags: part-identification, minifigure-identification
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# Question
Title: How to convert Passenger Train 7745 from 12V to Powered-Up?
I would like to **convert** the High-Speed City Express Passenger Train Set 7745 from the 12V track system **to the Powered-Up system**.

It seems to be trivial to exchange the old wheels with the new wheels, but I am looking for good ideas on how to embed the motor with the power block in the train.

The installation of the motor should match the old design nicely and the batteries should be easy to change. Any suggestions?

# Answer
> 3 votes
I would suggest placing the Powered Up hub in the front vehicle, replacing the brick-built 'engines' and 12v weights.

Parts required:

* Two 1x4 plates with two studs (no. 92593) in any colour;
* Two 1x8 bricks (no. 3008) in white;
* Four 1x2 bricks (no. 3004) in black.

Assuming that you are building the coach from scratch:

* In step 2 of the building instructions, omit the weight brick. Instead, place the two 1x4 plates across the chassis at opposite ends of where the battery box will stand (so there will be six studs in between them).

This not only makes it easier to remove the hub to change batteries, but lifts it clear of the pin on top of the motor.

* In step 4, substitute 1x8 white bricks for the 2x8 white bricks.

* In step 6, omit the second weight brick and substitute the four 1x2 bricks at each end.

* In step 7, replace the engines with the Powered Up hub.

I believe it would be possible to convert the headlights in the same vehicle to Powered Up lighting, by replacing the 12v light brick with a 1x2 brick with two holes (part no. 32000) and mounting the Powered Up LEDs in the holes. I don't think it would be possible to have the lights at the other end of the train illuminate, as the Powered Up light cable would not be long enough to reach both sets of lights at once.

# Answer
> 2 votes
My first instinct would be to replace the train weights in the locomotive with the battery box:

That will require a little reworking of the walls to be 1-wide throughout so the battery box can be included. You would unfortunately have to remove the engine details:

These are behind shutters, so it isn't a major cosmetic issue:

There are 9 modules of space between the rear engine and the front of that compartment, so you should be able to keep the rear engine intact if desired.

The roof on the rear of the locomotive should be easy enough to remove when you need to change the batteries. This process could be further simplified by replacing some plates with tiles and putting tiles under that battery box itself.

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Tags: trains, powered-up, set-modification, 12v
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# Question
Title: I want to get started making GBC modules. Which powered bricks standard to choose in 2023?
There seem to be two competing standards for powered LEGO modules in 2023.

* Power Functions
* Powered Up

I have read that Power Functions may be retired soon, but can easily work in a standalone matter. Powered Up seems to require Bluetooth devices and apps to work correctly.

I would like to get started building GBC modules with motors and, maybe, sensors. As both standards seem not to be compatible with each other, which one would be the most sensible to pick in 2023? I have to pick one before I start acquiring parts.

# Answer
> 2 votes
The GBC setups I've seen/participated in, have included modules using all kinds of electrical components, but mostly Power Functions (PF) since it's not hard to power those with a train regulator that can easily be attached to the power grid. Recently I've also seen some Powered Up (PU) controlled modules in a setup where most modules where PF.

But as you say PU modules require a bluetooth device nearby, and that gets impractical quickly. Some modules can share a motor, and probably a bluetooth controller, but I don't foresee the guys I know who has 100+ modules buying 100+ phones/tablets. I also don't know if it's possible to make several hundred bluetooth connections within a setup.

As it is now old parts (the train regulator probably takes the lead) are the best for GBC, but that's only good for a limited time (and mostly for those of us who already has a supply of those parts). But I have no idea what the future for GBC will look like (I'm fearing it will just die due to a lack of recent parts that are usable).

Edit: One of the things I set out to write, but forgot as I got into it: If you intend to exhibit your creations (and GBC modules are boring if not), you should also abide by any local rules your local LUG (or wherever you intend to exhibit) has.

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Tags: motor, power-functions, powered-up, gbc
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# Question
Title: Mindstorms program error when I play in download mode
I can run the program perfectly in the streaming mode, but it will flash a red light in the download mode after getting 5 points. Below is my program code:

...........Updated.............

Finally I solved it when I delete 2 define function and group in the program start. But I don't know why it work.

# Answer
> 2 votes
I believe the problem is due to nested custom blocks. I tried designing a very modular program once, but it would not download at all, and I believe it's because there were too many nested blocks. However, I cannot confirm this as it seems LEGO has published little to no comprehensive information on it's software.

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Tags: mindstorms, programming, robot-inventor
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title: What is this micro Mega Bloks element?

text:
# Question
Title: What is this micro Mega Bloks element?
I've got this Mega Bloks brick that's a 2x4 and it's smaller than the standard brick, it's 3/4"x3/8" and half the height as the standard brick. It was attached to a vehicle frame that also had two transparent red flat 1x1 that are 1/2cm attached to the frame where taillights would be. Does anybody know what set is it from?

I added photos of the frame. FYI there is a screw on the bottom.

# Answer
Guess could be 5902, instructions for sale on eBay, rally car. Could be all 4-wheel bases the same. Hopefully can add Modulex bricks to a base with wheels to make another car.
> 0 votes

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Tags: part-identification, set-identification, clone-brands
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# Question
Title: EV3 education brick doesn't work as is should
I have the EV3 education kit.

When I create a program and upload it to the brick and run it, the first time it runs very well and the robot goes in a straight line, then makes a 90 degree turn. But when I run it again it does not move the same way: it does not go in a straight line and turns 95 degrees or 86 degrees.

Can anybody help me find why?

# Answer
> 3 votes
Contrary to the previous answer, I *don't* believe that the problem is EV3.

I *do* believe that your problem is a hardware issue. I have personally run a test or two on this, and my conclusion is that the wheels are set off kilter on their axles.

The answer is bushings. Bushings are the little doodads that keep a gear or wheel in place on the axle. Put one on either side of a wheel, and the result is that those 90-degree turns, which produce torque on the wheel, relieved by movement along the cross-axle, will no longer set your wheel out of place. If this doesn't work, I would do as the commentators and other answer-er suggest, and make sure that your unit can hold a charge.

Measure this by telling just *one* motor with your EV3 unit to turn. Measure the amount of rotation. Now run the program again. You don't need anything attached on the motor, so as not to throw it off, and when the next turn program is run, you will have your answer based on the amount of rotation.

If it is lower, your EV3 doesn't hold charge anymore, and you need a new one. Sorry.

If it is the same, it is a structural problem, and you just need to make sure that nothing is moving noticeably out of place when running it.

# Answer
> 1 votes
So it appears there is nothing wrong with the structure of your robot, you just aren't confirming that the robot is turning its wheels the proper distance. I am not sure how to do that with the drag-and-drop EV3 software, but my recommendation is to have some sort of feedback loop that reads the rotation of the motors from their tachometers. If you can, make sure that the move block is combined with the other wheels move block and not separate so that the firmware can't think that it should start the moves at separate times.

There are firmware replacements out there that do this feedback loop automatically, if that would be a preferred option. This allows them to rotate exactly 90 degrees or move `x` centimeters.

You mention that you use the gyro, the last time I used that it seemed to be very hard to calibrate. If the reading from it drifts over time even though the robot is sitting perfectly still, that could be part of your problem during rotates as well (and perhaps traveling if you use it to drive straight).

# Answer
> 0 votes
I know that gyros can be unpredictable. I'd recommend displaying the output of the gyro to the screen, and watching it. Is it drifting even when the robot isn't turning? That may be why. The only fix I've found is to hold the robot steady, then unplug the gyro and plug it back in, all while the robot is being held still. Then, check if the gyroscope is drifting. If it is, repeat from step one.

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Tags: ev3, education
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title: Infrared Sensor Activation Problems

text:
# Question
Title: Infrared Sensor Activation Problems
I tried running my EV3 program that requires an infrared sensor, but it didn't work. I looked at the port view on the app and I saw the infrared sensor. It was connected, the brick recognized it but had a "---" on it. I tried restarting it, but nothing seemed to work. Any suggestions?

# Answer
That occurs sometimes if the cable is not fully plugged in. Try pushing the cable in where it connects to the sensor and the brick.
> 0 votes

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Tags: ev3
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# Question
Title: How to make a regular pentagon from technic bricks
For the purposes of this build, we need a pentagon (figure with 5 sides), that is regular (all sides have equal length), and it needs to be able to be mounted on a build (like a wreath) by a technic-friction-pin, (the little black ones).

This may be hard to achieve, with the given possible angles. The pentagonal shape *must* maintain its shape, no warping, etc. It must also be made of "properly fitting pieces."

# Answer
Using the same length ratios as in the construction that Philo posted in his answer I created this:

It uses length 5, 6 and 7 thin liftarms (5 of each) and 30 half-pins I'm quite happy with it!
> 6 votes

# Answer
A solution, using a (quite precise) approximation:  Granted, it's a bit bulky, but it could be reduced by half using 7.5 stud long stiffeners (eg. using Technic brick 1+ Technic brick 8 +plates)

Link to LDraw file: http://www.brickshelf.com/gallery/Philo/misc2/pentagon/pentagon.ldr
> 5 votes

# Answer
Recently came across this problem again, so I'd like to post another answer (2 answers actually).

I figured out how to create an "exact" pentagram (no approximations) using only swivel plates and turntables (blue in the picture):

The math very shortly: cos(Pi/5) = (1+sqrt(5))/4 and sqrt(5) can be created with a (2,sqrt(5),3) righthanded triangle.

I posted this in the FB group "LEGO math and patterns", one of the group members mentioned a paper "Mecanno math" by Gerard ’t Hooft which can be found here, which has several elegant solutions, e.g. figure 7 in the paper lists 6 solutions:

It should be straightforward how the Meccano strips can be replaced by Technic liftarms (as the original poster asked).

Another response I got in another FB group is that this constructions works quite well:

I tried it and they are correct, the pentagon is rigid and the elements do not seem under undue stress.
> 2 votes

# Answer
I would suggest you use 10 of either one of these: 4273 Technic, Axle and Pin Connector Toggle Joint Toothed or 4273a Technic, Axle and Pin Connector Toggle Joint Toothed - Without Slots, together with 5 equal length axles and 5 pins. Creates a sturdy pentagon. Use the pin connector hole to attach the pentagon to other structures.

If you don't want axles, but bricks, you can mount connections onto the bricks to mount these 4273s the same way.
> 1 votes

# Answer
A right triangle with sides 3 by 1 has as largest angle 71.5650512 and smallest 18.4349488 degrees. That is reasonably close enough to 72 and 18 degrees which can be used to create a pentacle. Lots of right angled connectors or beams you could use then...
> 0 votes

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Tags: building, technic
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