# Question
Title: I came across these and cannot identify the set - greys, tan, orange, darker green
I came across these and cannot identify the set. Can anyone help me with identifying the set?

# Answer

> 8 votes

---
Tags: set-identification
---


# Question
Title: Has any non-Duplo LEGO set included Duplo components?
It’s not uncommon for LEGO Technic components to be included in LEGO builds - especially where motion or interaction is needed.

Has the same ever happened with a Duplo component being included in a ‘classic’ LEGO set? Perhaps using their extra size to help build up an area.

(In case clarification is needed, we can define Duplo components as being anything listed under Duplo in the LEGO pick-a-brick service. And any set not branded as Duplo or Technic can be considered a ‘classic’ LEGO set).

# Answer
> 27 votes
One instance I can think of is the 52 mm ball, usually used in the DUPLO Ball and Tube system, being present in a couple of "classic" sets. Most notably the Indiana Jones Temple Escape, 7623

https://www.bricklink.com/catalogItemIn.asp?P=41250&in=S

It's also present in quite a few Mindstorms and Technic sets, where it is usually used as an object to be grabbed by a gripping mechanism.

# Answer
> 11 votes
There was almost (probably) a Technic BIONICLE set with a Duplo tread piece.

That set would have been the Sand Tarakava (low-res, high-res, other), a smaller set that was meant to compliment the 8549 Tarakava set.

This prototype set was given to Saffire to develop the cancelled 2001 PC video game, and later changed hands.

Ultimately this set was not produced, so it's possible it would have undergone additional revisions if it had been. Changing the tread seems like it would have been a rather drastic change though, especially compared to the minor changes seen in other prototype models Saffire worked with.

---
Tags: duplo
---


title: Trading and Lego VIP

text:
# Question
Title: Trading and Lego VIP
What websites can be used for trading? I want to have as many rare ones without buying anything. Does someone want to trade a Lego minifigure for free? I have been trying to get many Lego minifigures for a stop-motion movie.

Finally, how do I get all my free stuff from Lego VIP without buying anything?

# Answer
> 3 votes
The go-to sites regarding LEGO brick trading are bricklink.com and brickowl.com. They operate as marketplaces where people can buy and sell sets, parts and minifigs alike. There is one site I've found that is marketed as a dedicated place to trade (or in other words swap) minifigures: swapfig.com \- Note that there is not much experience with this platform, so exercise caution when operating there.

Regarding the "Finally" part: I don't know of any such opportunities, could you please clarify what have you heard/read and where?

---

Edit based on OP's comment:

LEGO VIP is not a new thing, but it is not about free stuff. You can register an account, and then collect VIP points with every purchase on LEGO.com. These points can then be exchanged for discounts or promotional sets. Sometimes minuscule amounts can be earned by other activities, like completing surveys.

---
Tags: shopping, trading
---


title: Salt Lake City Temple: Temple doors

text:
# Question
Title: Salt Lake City Temple: Temple doors
I'm building the lds temple in Salt Lake City in lego. I'd like to represent the temple doors as seen here:

My current plan is to use the stockade as the base door:

...and probably put a plate over it then use 2x2 pearl gold plates for the background, then put some decorated 2x2 rounded tiles such as this one or this one. Can anyone suggest an approach to represent the gold filigrees in between or any other part of this?

# Answer
> 6 votes
Judging by some photographs, the size of the doors is roughly the same as that of the window arches, and judging by one of your previous questions, those are 2 studs wide and about 4 bricks high.

Therefore, I suggest building the doors at that size: 2 studs wide. IMO the right size will help the build as a whole, even if you have to sacrifice detail. Something like the following should work:

Parts:

---
Tags: building, design
---


# Question
Title: Mistake with hook holder (steering arm with round socket) on Technic Helicopter 42145
I made one small (but costly) mistake in my otherwise very satisfying build for the Airbus helicopter: at step 66, I connected the grey piece "steering arm with ball socket" the wrong way. And of course now that I need it at step 744(!), the socket is facing up instead of down, and it is impossible to attach the hook. Can anyone here see a not-too-painful way of fixing this? Otherwise I will just have to give up on that hook. Thanks!

# Answer
> 4 votes
As you can see from building step 66 and 67 the beam is held with a length 7 axle and a blue length 3 pin.

I'm afraid there is no easy way to flip that beam without partially deconstructing the model.

You can deconstruct either severely on one side until you can access the axle and take it out with pliers, or less severely on both sides so you can push the axle through with another axle.

Likely the blue pin will not give you much trouble, if the model is deconstructed enough to remove the yellow axle, there will be enough wiggle room to force out the beam with pin and all, Lego Technic is rather flexible like that.

One tip to make the process less painful: photograph each step you did while deconstructing the model. Then reverse the order of the pictures and you'll have yourself a list of instructions to put the model back together.

---
Tags: technic, building
---


# Question
Title: Any idea what set any of these are from? mostly minifigs and decorated bricks
Just bought a random mixed box on Facebay, trying to work out what sets might be there. These are the most distinctive pieces.

# Answer
> 6 votes
I can identify:

Note that you've got some parts from clone brands - notably the "policeman in swimming shorts" minifigure, and the aforementioned head on the red "Divers" torso.

I have doubts about the worker in orange hard hat - the head might be from soc151, or from a clone brand (I recall that particular face expression being common in clone brands), plus there are no hard hats in orange.

I also have doubts about the 1x8 bricks with "fire" sticker being from a clone brand.

---
Tags: part-identification, clone-brands
---


# Question
Title: Lego 21323 Grand Piano - After setting up app on page 110 of instruction, the gear is turning anti-clockwise instead of clockwise as shown
After completing all builds till page 108 of the instructions, I installed the app. But when I press play on a song the gear move for a quarter turn anti-clockwise but the picture on page 110 shows clockwise.

What should I do

(from https://lego.brickinstructions.com/en/lego\_instructions/set/21323/Grand\_Piano)

# Answer
Converting comment that lead to an answer.

Looking at the picture the first thing that gets my attention is the position of Technic, Gear 20 Tooth Bevel. Particular part placement has a room for error - yellow half-bushing, placed on the same axle could easily be swapped with mentioned 20T bevel gear. This kind of error would reverse the rotation when operated.

Could you confirm if is installed as shown in the picture? And not on the right (closer to us) side?
> 3 votes

---
Tags: building, motor
---


title: What logos appear on Duplo brick studs?

text:
# Question
Title: What logos appear on Duplo brick studs?
Do all regular Duplo bricks have the word "Duplo" written on their studs? If not, what variations are there?

# Answer
There really isn't a "on" for the Duplo studs. All Duplo studs are hollow studs. In the interior of the stud, depending on set and the year of the piece, the stud will read:

> DUPLO

or

> LEGO
> 9 votes

# Answer
Before 2002 LEGO used "Duplo" inside studs. In 2002 they tried to drop the Duplo brand and possibly for this reason all new Duplo moulds have "LEGO" in the studs. Rare pieces like the 2x10 brick still use an older mould, so still have "Duplo" in the stud. Also from 2012 some sets at least in Europe have 2x4 bricks with "Duplo" in the studs. It's possible these are repaired old molds.
> 7 votes

# Answer
An example of 2 different moulds:

The inside (or underside) of the parts differ as well:
> 5 votes

---
Tags: duplo
---


# Question
Title: How do I determine which set these belong to? Lots of yellow and blue, wheels, some grey
How can I determine which set this is?

# Answer
60079-1 Training Jet Transporter

Based on

* Yellow Bracket 1 x 2 - 2 x 4
* Blue Plate 6 x 6
> 4 votes

---
Tags: set-identification
---


title: LEGO brick competitors?

text:
# Question
Title: LEGO brick competitors?
I'm trying to find all the competitors to LEGO. I know there is MegaBloks. What are some more?

The base idea is that they should be bricks and they need to connect to each other like LEGO. However, it does *not* need to be compatible with LEGO.

Also open source designs are always welcome!

# Answer
> 7 votes
Disclaimer: some of these retrieved from the lugnet off-topic/clone-brands group; they also mention "Art Asylum’s C3 Brand" but the site doesn't seem to work.

# Answer
> 4 votes
In terms of semi/incompatible systems, there's a number of them that are supported through the Free Universal Construction Kit files for MakerBots and other 3D printers:

> The Free Universal Construction Kit offers adapters between Lego, Duplo, Fischertechnik, Gears! Gears! Gears!, K’Nex, Krinkles (Bristle Blocks), Lincoln Logs, Tinkertoys, Zome, and Zoob.

# Answer
> 1 votes
Besides the resources mentioned by others, you might also be interested in this excellent compilation of all LEGO knockoff products and competitors titled Communist LEGO. It is in a form of a PDF and is a highly enjoyable read: http://www.1000steine.com/brickset/miscellaneous/clonebrands.pdf

# Answer
> 1 votes
Wikipedia has a pretty complete listing as well.

> * Ausini
> * BanBao
> * Best-Lock
> * Brictek
> * Built to Rule
> * Cobi
> * Character Options
> * CoCo
> * Cogo
> * Enlighten Brick
> * K'nex (Note: some sets feature Lego-compatible studs)
> * Kre-O
> * Laser Pegs
> * Lite Brix
> * Mega Bloks
> * Nintendo (Manufactured Nintendo Block, later rebranded N&B Block)
> * Oxford
> * Rokenbok
> * Sluban
> * SY
> * Star Diamond
> * Tyco Super Blocks
> * Super Blox

From the back of my head, I would also add

* Ionix (Tenkai Knights)
* Nanoblock

# Answer
> 0 votes
LEGO-like, but not compatible? Nano Blocks. http://www.mynanoblock.com/site/

# Answer
> 0 votes
Montini; made in the '60's in The Netherlands, but Lego put a stop to that. Compatible underside in alternative positions if Lego doesn't have hollow stud for ×2's (the ×1's okay), as has pins, studs taller so Lego plate leaves a gap.

Large Mega Blocks fits atop Duplo, although they also make fully compatible.

Tente of Spain, hollow studs, brick with same N° of studs rests atop Lego, but not holding on.

Unknown British, a fraction smaller as using inches, used it at primary school in the 1960's.

Pennybrix, ~1964 by tri-ang. L-shaped studs.

---
Tags: 3rd-party
---


# Question
Title: Lego 21327: How do I attach the typewriter segment to the body?
Typewriter build step 312. Red arrows point to two upraised open connectors. What part of the segment snaps into them?

If snapped to the rod outside of the two gray mid-rod spacer pieces (step 309), the resulting gap exceeds that of the two 90 degrees vertical rods that the connector pieces connect to.

The image is from https://lego.brickinstructions.com/en/lego\_instructions/set/21327/Typewriter

# Answer
> 4 votes
The step you mentioned (#309) shows two grey connectors (Plate, Modified 1 x 2 with Bar Handle on End) in exactly right configuration for this connection:

It seems a clear case for these to be meant as the intended connection points.

---
Tags: building, ideas
---


# Question
Title: Piece stuck in LEGO T-Rex body part nr. 6223585
My son stuck a rod piece through one of the openings in the T-Rex body middle part (part# 6223585). How can I open up the body to retrieve the rod piece?

The body is made of two parts that are clipped together I think. When looking inside, there seems to be a connection in the inside of the body as well.

Does anyone have experience with how to open up this piece with minimal damage?

The rod piece is completely inside the body piece, rattling around. He inserted it through the hole for the head or tail

# Answer
How to get a part out of TRexBod: https://youtu.be/wHsnLP1xuHY
> 1 votes

---
Tags: disassembly
---


# Question
Title: White bricks slightly different, real, fake or old?
These white bricks are slightly different, one of them has the copyright lego on the bottom and the other only has the ID number and some other numbers on the bottom, and the way light enters the brick is totally different (see photos)

They all have the Lego logo on the studs, however. What is this? Are they old, fake or just a mold variation?

# Answer
> 5 votes
These are almost certainly genuine LEGO elements. I've personally never encountered a clone brand that misused the LEGO trademark on bricks. The issue with the light that you described is well known.

TLG has adjusted the way to color is added to plastic, the color of the pigment used, and the amount of pigment used at various times. This leads bricks produced at different times to have slight color variations and differing levels of translucency. This is a known issue even in current sets. For example, LEGO is aware of an issue with the white tiles the Great Wave (31208) set:

Here's an example showing obvious color and translucency variation that was present in the tiles that was shared on the LEGO Ambassador Network:

---
Tags: clone-brands, colour
---


# Question
Title: How has the basic brick changed over the years?
The basic 2x4 brick has many versions. For example the modern one has thinner walls and funny shaped tubes compared to an early 1980s brick. What were the changes over the years and how did they affect building?

# Answer
> 22 votes
I can't provide a list of all the minor changes, but I can at least tell the most significant change made in the history of the basic 2x4 brick (which applies to all other bricks and parts, too):

In general, there are **no essential changes** made: a brand-new brick still fits together with one from before 1963 as long as the Cellulose Acetate hasn't deformed too much during ageing (which is the main reason they switched to ABS, it's more robust, scratch-proof and doesn't deform so easily).

The main "change" that really affects building is the continuously **improving precision in production** \- this happens all the time, so there's no point on the timeline. The effect is simple: better fitting bricks improve the stability of your construction.

**Transparent bricks consist of Polycarbonate, axles consist of Polyamide*

# Answer
> 2 votes
This diagram from WRme2 on Flickr provides a representation of the mold variations from 1949 to 2022:

# Answer
> -3 votes
* Hollow tube 1958 (2×4 weighing 3g)
* Gets a horizontal ridge called a flowrib & end pips, holds together better (now 2•68g)
* Colours charge & black shine, maybe from being made from ABS instead of CA?
* ABS 1963
* Flowrib removed (= weight)
* In USA gets slits in tubes
* As Pat. Pend. ends, those words get obscured, & stud pips instead of side pips 1974
* 2×3 & 2×4 get cross-members, ribs & thinner walls (2•25g) (sorry I don't get the joke? tubes still round). \[2×2 gets ribs\]
* The N° for 2×4, 3001, inside those bricks.
* ##### & for the 1×
* 1×2 1955
* Gets pillars (not for 1×1), 1×6 now has 1 cross-member instead of 2 1959
* Gets full depth cross-members, & 1×6 back to having 2 (but there is also some with just the 1)
* Cross-members on all pillars, & not full depth again
* Hollow pillars

The 1st using tubes, & 1× sans pillars don't hold together well, okay for buildings. Must be bigger under & smaller studs? Some one wrote that the new thinner bricks don't hold as well on underside. I've 1×2 with notch for wires, hold together okay, even though no pillar, but guess the pillars must help.

With cross-members & ribs, when I tested using bricks that came just before, holds less well underneath, using 6 studs there holds less well than 4 atop. But better with the 1st using tubes, 4 underneath better than 8 atop. But no better at holding 1 stud under.

---
Tags: manufacturing, history
---


# Question
Title: I cannot find the set these bags of Lego bricks belong to - lots of greys and dark reds
I cannot find the set these bags of Lego bricks belong to. Can anyone help?

# Answer
The bottom polybag contains 92946 in light bluish gray, 32523 in light bluish gray, and 3666 in tan. That combination of parts appears only in one set: 75243 Star Wars' Slave I, 20th anniversary edition.
> 6 votes

# Answer
Top right polybag appears to be from one of two Death Star - UCS sets: 10188 or 75159
> 4 votes

---
Tags: set-identification, star-wars
---


title: Compatibility of sports ramps

text:
# Question
Title: Compatibility of sports ramps
Are these relatively recent "sport ramps":

https://www.bricklink.com/v2/catalog/catalogitem.page?P=75538

compatible with these older "sport ramps" https://www.bricklink.com/v2/catalog/catalogitem.page?P=43086  https://www.bricklink.com/v2/catalog/catalogitem.page?P=43085

and these corner pieces ? https://www.bricklink.com/v2/catalog/catalogitem.page?P=43086

With "compatible" I mean the concave sides can be aligned by an integral number of modules or plates and the circles describing the shape have the same radii. I would also be interested in what the actual radii for the elements are.

# Answer
I've put those two parts side by side in LeoCAD, and it's quite obvious they have different shapes:

A side view illustrates the difference even more clearly:

They will somewhat align if one of the ramps is rotated **exactly eleven degrees**, like in the following diagram:

Do note that while it's easy to align bricks at increments of 15 degrees with hinge parts (and a few other amounts by resting over sloped bricks), eleven degrees is a hard angle to achieve.

As user @SanderDeDycker pointed out, it's also possible to align the ramps without rotating them, with a vertical offset of *slightly less* than 2 plates, and a horizontal offset of *about 2.3 studs* \- again, dimensions that are hard to achieve:

Applying a bit more CAD, I *estimate* the radius of the slope to be 11½ studs. Note how, in the following diagram, the left tangent line crosses the last stud of the grey ramp; and that the grey ramp is 12 studs deep.

A bit more fiddling with CAD tells me that the "new" ramps (75538) have a slope radius of 12 studs instead.

Please keep in mind that my measurements are based on the LDraw models, and I have spent very little time on them, so they might not accurately reflect the dimensions of physical bricks.
> 11 votes

---
Tags: piece-information, compatibility, piece-usage
---


# Question
Title: How to run Power Functions LEDs from a 12v supply?
I am considering building a train that uses a 12v motor from the 1980s and Power Functions LED lighting. For this to work it would be necessary to run the Power Functions LED set from one of the 12v sockets on the motor.

Obviously the physical connection is not compatible, but it should be straightforward to remove the connector brick from a Power Functions cable and fit 12v-style plugs instead. Where I'd welcome information is the electrical aspect. Since the LEDs are designed for 9v, exposing them to 12v may damage them, and they will need a resistor in series to reduce the voltage across the LED set to 9v.

Has anyone determined the correct value of the resistor? Or the current that the LED set draws at 9v, which would allow the necessary resistance to be calculated using Ohm's Law.

# Answer
https://www.philohome.com/pf/pflights.htm

So the leds draw 2mA, a voltage drop of 12-9 = 3 V is required. So Ohms law says you need about a 1.5 kOhm resistor in series to have the leds shine at the same brightness...

On the other hand, it could very well be that the only consequence of omitting the resistor is that the leds shine 30% brighter... you could test and monitor if the leds heat up. If you cut off power fast enough as soon as you feel them heating up, it's unlikely that they would be damaged.
> 4 votes

# Answer
using the numbers on the page that Michael linked to, I calculate 1mA per LED which is very low. When increasing the voltage to 12V I calculate 1.7mA per LED which is of course 70% brighter but still very low\*. Therefore I think it will work just fine with 12V.

* Random LED circuits are often designed for 20mA and this is fine. 20mA is often used due to outdated design advice for the less-efficient LEDs from 30 years ago. With a modern LED, 20mA is annoyingly bright and that's why the power light on your TV keeps you awake.
> 1 votes

---
Tags: power-functions, 12v
---


title: Lego 88012 hub socket type

text:
# Question
Title: Lego 88012 hub socket type
The LEGO Technic hub 88012 has 4 sockets. Can anyone tell me what the socket types are?

I have tried to find out via LEGO Support and they directed me to this site.

I have searched the internet and been unsuccessful.

I want to use the hub to build MOC, hence my question.

# Answer
Here's a photo of the hub:

It includes four Powered Up ports. These are compatible with peripherals (motors, sensors, lights, etc) from the lines branded as Powered Up, Control+, Boost, Robot Inventor, Wedo 2.0, and SPIKE.

If you are hoping to make custom electronics for this, the port itself uses a proprietary connector that is not widely available. You may be able to find connectors online, or build something that might work.
> 2 votes

---
Tags: technic, powered-up, connections
---


# Question
Title: Can anyone help me identify what set this pack is from please? white pieces with a distinctive minifig
Hi, I am struggling to identify what set this pack is from. It came randomly with a box of various toys, so nothing for reference!

# Answer
70595 Ultra Stealth Raider is the only set on BrickLink with

* 973pb2520c01 Torso Ninjago Tunic with Light Gray Trim and Belt, 3 Dark Gray Ties with Gold Buttons, Dragon Symbol on Back Pattern / White Arms / Sand Green Hands
* 970c00pb0589 Hips and Legs with Silver Sash and Knee Straps Pattern

(Note: the torso and the legs are from two different figures.)
> 5 votes

---
Tags: set-identification
---


# Question
Title: How do I build my LEGO slope so it connects to the flat top without any notable ridges?
I'm currently building a functional LEGO escalator that is minifigure-scaled and with staircases transitioning from flat platform to stairwell to flat platform. Here's my progress so far:  Here's the stair design I use for this escalator:

Now that I have clearly defined the necessary framework for the slope, I am currently working on the escalator's flat top (yellow). However, I couldn't come up with any designs for getting the flat top to "connect" to the slope without any ridges or gaps that could catch the stair's shafts.

My ideal result should resemble this design, with the slope still retain a 39.5 degree angle and the top has to be flat:

Ideally, this build should utilize legal techniques for ensuring stability due to its technic nature.

I want to create an escalator like this but at a minifigure scale, therefore I don't intend to use LEGO's dedicated escalator piece.

Bricklink and any Pick-A-Brick retailers of similar fashion are not locally available for me, and I don't have the necessary bricks at my disposal, so therefore I couldn't physically test out my builds.

# Answer
> 1 votes
An update on my query: I've figured out a design that can reasonably get the slope to connect to the flat top with as little ridge as possible: using a 1x2x1 panel to extend the brick slope using a SNOT bracket, and fitted with a cheese slope wedge on the flat top also with a SNOT bracket. Here are the Stud.io renditions of the design:

As far as Stud.io and the real model shows, this seems to be a legal building technique. However I am still not sure, as the slope might induce stress on the slope.

---
Tags: technic, building, moc
---


# Question
Title: Can 9V train motors be linked and work together via the top power stud connection?
I'm building a MOC based on the 10219 Maersk Train, but going for the classic track power 9V system given the removal of need for batteries and slowly increasing availability of new 9V parts from third-party supplier FX Bricks.

I was wondering about dual-motoring my locomotive, and hit upon the idea of using the Technic axled motor from the 9V RC era (as used in the Cargo Train Deluxe 7898 set), linking it to track power via a 9V extension wire attached to the power studs atop it and going to those atop the classic 9V track powered motor. My thought is that in using the motor with silicone traction tires in addition to the metal-wheeled classic motor bogie, it may be possible to get even better traction and pulling power.

I'm still learning about LEGO trains after getting back into them many years later, so I'm not sure if the transformer could handle it (other folks I've seen have said that the controller overheats running two motors for a long period of time), or if those top power studs can even transmit the power required for running another motor.

Can the components be used as I'm thinking, or have I gone wrong in my thought process somewhere?

# Answer
> 2 votes
The basic premise of your idea is sound: the metal-wheeled train motor can indeed receive power from the track and forward it to the studs on top of it. Then an extension wire can be used to power another motor. The only possible problems I might anticipate are:

1. possibly mismatched velocity (due to either voltage drop, different internal gearing or different wheel diameter)
2. the operational limits of the

* power supply unit (shouldn't be an issue, as two metal-wheeled train motors can run on a track powered by a single supply)
    * or the pass-through capacity of the 9V train motor (as it was designed to pass through enough juice to power lights, not motors with their significantly larger consumption)

The good news is that none of these are showstopper issues even if they prove to be a problem, and you can quite easily test all of them - so let's start building :)

---
Tags: motor, trains, moc, 9v
---


title: Lego Creator - Ford Mustang 10265

text:
# Question
Title: Lego Creator - Ford Mustang 10265
I open the box I purchased - the box had been opened prior - no instruction manual nor stickers - not a big deal, but how do I know how many bags I'm supposed to have in the box. I watched video and someone said 11 - but his numbers 22 were different. I have 1, 11, 2, 3, 33, 4, 44, 5, 6, 66 - am I missing 22 and 55? In total I have 1-6 big bags, and 11, 33, 44, 66 little bags. Help please. I don't want to open each bag and count the parts individually

# Answer
> 2 votes
There should indeed be 11 bags :

* 6 big ones numbered 1 through 6
* 5 small ones numbered 1, 2, 3, 4, 6 (each has the number on it multiple times, which seems to be why you mention 11, 33 etc.)
* the instructions and sticker sheet are in a protective plastic bag as well.

So, you appear to be missing small bag number 2.

---
Tags: sets, instructions
---


title: How To Disassemble the LEGO Boost Hub?

text:
# Question
Title: How To Disassemble the LEGO Boost Hub?
I can get the hex screws off and pry apart the plastic tabs on the bottom plate, but for the life of me I can't un-clip the back tabs.

Any ideas on where to press/pry?

# Answer
> 9 votes
*Here*'s a *YT* vid on the disassembly, but the still picture shots with no commentary may not be what you need for a good walk-thru.

I don't have a Hub, but wish we all had a pic to make sure we're talking about the same piece.

Regardless, I'm gonna take a crazy shot at it. Let's Go!

We have two gray rectangles:

* *Big Gray Rectangle* on the Left.
* *Small Gray Rectangle* on the Right.

I think you're stuck here. (See the picture).

So, you took out the two hex screws, (two empty black holes on the *Big Gray Rectangle*), and you say you can't get further. Correct?

Instead of trying to remove the *Big Gray Rectangle* plate, first remove the Phillips screw in the middle holding the *Small Gray Rectangle* down.

Look at the next picture.

See how the *Small Rectangle* has a lip design that overlaps, and locks down our *Big Gray Recky-reck*?

You should be good from here.

**EDIT**+++++++

***Real issue***: White Tabs won't release.

* Look at this next image of the *Big Gray Rectangle* removed below.

* Focus your attention to the white tabs.
* Do you see the notches on the tabs?
* The *inverse* of those notches are on the inside lip of the *Big Gray Rectangle*.
* When all notches are together it forms a *Mechanical Lock*.
* We have to disengage both tabs together.
* Position the entire piece like the picture below.
* Get two flat head screw drivers.
* Put both screw driver heads on the LEFT side of both tabs.
* Hold both screwdrivers in one fist like *Wolverine's* daughter.
* Now pivot to the LEFT which should separate the physical locking of the two pieces.
* You might need your other hand to lift *Big Gray Rectangle* up
and off.

# Answer
> 1 votes
I had to do the same last night because the internal motor position A did not work. I ended up pushing a small screwdriver from in between the housing, not from the tabs since I felt that would deform the plastic even more.

Fun fact: to solve my encoder issue, I simply had to nudge the sensor a bit closer to the perforated wheel, using some tweezers. I wonder how it ever worked - or stopped working - in the first place.

Here are some pictures from the parts for future reference:

---
Tags: disassembly, boost
---


# Question
Title: Why are there many hidden holes in 'Monkie Kid’s Team Van' 80038?
Lego set 80038, 'Monkie Kid’s Team Van', repeatedly uses yellow Technic Brick 1 x 1 with Hole (item 654124) where it could simply use a standard 1 X 1 brick (item 300524).

For instance, in Instruction Booklet 2, you can see where these brick holes are covered up in step 120, or even immediately obscured in step 150.

Is there a design rational for the use of these bricks (a significance to Monkie Kid, or Chinese culture in general?) or is it more likely a simple surplus of Technic Brick 1 x 1 with Hole?

# Answer
> 19 votes
This likely has to do with the cost to manufacture the set. It is logistically simpler, and therefore more cost effective, to add an additional element already present in the set rather than to add a new unique element to the set.

The Technic element you mentioned is used functionally in the set to attach one of the doors:

This Technic element is then reused in several places throughout the build where a 1x1 system brick would typically used. This saves having to include the 1x1 brick in yellow in this set.

---
Tags: technic
---


title: Pink or Bright Pink?

text:
# Question
Title: Pink or Bright Pink?
Sorry for the slightly blurry photo, but what would you say this is? These two pinks are a little different, very slightly. Is the above one old pink and the bottom one bright pink? Or are they both bright pink?

Can anyone send a comparison pic of pink and bright pink?

# Answer
Top is Dark Pink

Middle is Bright Pink

Bottom looks like Salmon to me, but based on the old jumper plate it has to be Pink.

Underneath are Light Bluish Grey and White. Photo taken in sunlight.
> 4 votes

---
Tags: colour, quality
---


# Question
Title: Which Lego set do I have? mostly yellow and seems to be based off of construction
The Lego set includes one minifigure with a blue cap, a red shirt, and blue pants. It also includes a window piece, some yellow connections, a black digger piece with the same connection and wheels. The set is mostly yellow and seems to be based off of construction. I tried to find it on other sites, but couldn't find anything. The set appears to be from the 2010s, and seems to be made for younger kids, but not quite Duplo.

# Answer
> 1 votes
Best match I can find fitting that description is set 4667 - Loadin’ Digger from 2004.

This set is from the 4 Juniors line, and features a non-traditional minifigure, larger than the iconic ones, from the Jack Stone line of figures.

---
Tags: set-identification
---


# Question
Title: What is the gyro sampling rate on the Spike Prime hub?
I was wondering what is the inertial measurement unit sampling rate, because for my project I need 800 Hertz. I tried to look in the firmware file but I didn’t find anything. I use the `pybricks` firmware on a Lego Spike Prime hub.

# Answer
> 4 votes
Digging a bit into the C source code for the `pybricks` firmware, I was able to find these two lines:

```
PT_SPAWN(pt, &child, lsm6ds3tr_c_xl_data_rate_set(&child, ctx, LSM6DS3TR_C_XL_ODR_833Hz));
PT_SPAWN(pt, &child, lsm6ds3tr_c_gy_data_rate_set(&child, ctx, LSM6DS3TR_C_GY_ODR_833Hz));

```

...which means that the IMU is set to a sampling rate of 833Hz.

Please note that this is how the IMU electronics are configured when `pybricks` starts - this *does not necessarily mean* that the `pybricks` firmware nor the hub's microcontroller CPU can keep up with that rate, or that they can run some of your python code 833 times per second, or that `pybricks` will run python code at that rate.

It should be possible to change the sampling rate by modifying the `pybricks` C code and recompiling the firmware. If you want/need to take on this endeavour, read https://github.com/pybricks/pybricks-micropython#development first.

# Answer
> 2 votes
In the comments of one of the accepted answer on the question here: What internal electronics do Spike Prime and Mindstorms Robot Inventor use? it's mentioned that the pybricks people have determined that the IMU module is a STMicroelectronics LSM6DS3TR-C.

Googling for this I found the following document on the manufacturers website: https://www.st.com/resource/en/datasheet/lsm6ds3tr-c.pdf Which list output data rates from 1.6 Hz to 6.6kHz, probably depending on which mode the chip is configured in... I have no way off knowing which mode/value applies, but perhaps someone else does...

---
Tags: programming, spike-prime, gyro
---


# Question
Title: questions on an Assembly Square fountain redesign
I'd like to reproduce the fountain posted here Can anyone identify the parts used to make the wide blue/water rims on the 2nd and bottom level? Also, how do I attach the squiggly water bursts on the 3rd level?

# Answer
> 4 votes
According to the YouTube link, the squiggly water bursts are just held by friction - they're not clipped in to anything.

The blue layers are just normal dishes (of different sizes, of course).

---
Tags: design
---


# Question
Title: Is there a way to keep fragile models together?
My late husband built a number of Lego models that I would love to keep together. However having a 5 and 2 year old around this is proving difficult and parts keep getting knocked off. Is there any kind of spray glue type thing that I can use to hold the models together so they can stand up to curious little fingers. I know this not the best idea however I do not want them to end up in smithereens as I know they will never be remade again. I want to preserve the work my husband put into them.

# Answer
Sorry for your loss.

I would hide them behind a locked glass door; even if you glue them, they won't likely survive a 2-year-old knocking them to the floor.

There is a product called Le-Glue (amazon link) which I've never used which bills itself as temporary glue (you can dissolve it with water).

And, of course, there's always the .
> 2 votes

---
Tags: building, glue
---


title: EV3 with 6 motors

text:
# Question
Title: EV3 with 6 motors
My son has made a crane with 6 EV3 motors connected to an EV3 hub. He's used ports A,B,C,D and 1,2.

But two of them don't work. Are ports 1-4 just data ports for sensors, not motors?

Is 4 the maximum number of motors?

What happens if we invest in a Spike hub?

# Answer
On Powered Up hubs like SPIKE Prime, all ports are the same and can be used with motors or sensors. That means you can use 6 motors and no sensors if you need to on SPIKE Prime.

On EV3, ports A-D are for motors only and ports 1-4 are for sensors only. So EV3 is limited to 4 motors (NXT is similar but limited to 3 motors).

EV3 and SPIKE software and motor/sensor hardware are not compatible, so if you invest in SPIKE Prime, you will need to make a new program and adjust your build since the motors don't have the same form factor.

Another alternative could be to daisy-chain two EV3s. This would allow up to 8 motors since each EV3 can have up to 4 motors.
> 5 votes

---
Tags: ev3, motor, remote-control, spike-prime
---


title: LEGO BOOST failing firmware update

text:
# Question
Title: LEGO BOOST failing firmware update
We have a LEGO BOOST kit. When going through the initial setup, we get as far as connecting the move hub to the tablet and then it asks if we want to do a firmware update. There is no option other than 'OK'. The light on the hub flashes pink briefly and then goes out. The progress bar doesn't progress, and then it reverts back to the screen asking us to turn the hub back on.

# Answer
I fixed this by installing the powered up app and performing the update through this.
> 9 votes

---
Tags: software, boost
---


# Question
Title: What Lego set would this building belong to? grays and red flags of different sizes
What Lego set would this building belong to?

I cannot find the logo on the flag.

# Answer
> 4 votes
I searched BrickLink for `2335p*` and then restricted the color to `Red`.

According to BrickLink, the only set with 2335pb013 Flag 2 x 2 Square with Avatar Fire Nation Black Lines and Fancy Scroll Pattern is 3829 Fire Nation Ship

---
Tags: set-identification
---


# Question
Title: Is it possible to have a motor default to a certain position at the start of the code? I'm trying to use the motor as a servo, and it's annoying
The motor is attached to a "door", which rotates to block off an opening. I have it coded to manually go back 1/4 of a rotation, and the distance sensor attached will send it forwards 1/4 of a rotation. However, if it gets triggered twice, then it has to be triggered another two times in order to get back to the default position. I would like to avoid this. I am coding on a laptop, and there is no block that I have seen that can do this. Is this possible, or did I just miss the block?

# Answer
Expanding on @zovits approach for a rubberband-based mechanical system: I'll suggest something like the following diagram, adding a rubber band between the bush and the belt wedge wheel:

That can technically be called a friction clutch. With something like that, it's possible to keep the motor turning more than needed: when the cyan liftarm hits the red corner beam, the axle will block and the rubber band will absorb the excess rotation (by means of slipping on the yellow bush).

In order to minimize wear&tear, you should adjust the rubberband tension so it provides just enough grip, but can slip easily.

---

A similar approach is to use 60c01 Technic, Gear 24 Tooth Clutch or 6542 Technic, Gear 16 Tooth with Clutch:

I don't own any such pieces, and therefore I don't know how well they stand wear&tear - I'd recommend a rubberband just for the ease of finding replacements.

---

Another approach is to use a linear actuator:

A technic linear actuator has a built-in clutch, so will absorb extra rotation as well. That means you can run motor more than needed to get them into a known state (either fully retracted or fully extended).

By building an assembly as shown above (and securing both the motor and the black axle, but letting the linear actuator swing around the motor's axle), extending the actuator will make the black axle rotate about 90 degrees. You'll need to adjust the system to get the desired rotation angle.
> 3 votes

# Answer
For an ordinary motor it is not possible, as the axle position can't be queried from the software. What you can do though is to write your software in a way to return to the starting position before ending the program (define a counter for the number of trigger events, increase it every time, then at an appropriate point apply the necessary amount of reverse movement).

Another possibility is to build in a mechanical system that returns the axle to a pre-defined position (with force from gravity or a rubber band) and set the motor in feathering mode to let it turn without resistance until the starting position is reached.

The most convoluted way is to build your own position encoder: set up a sensor (push button, colour sensor or ultrasonic) that can tell when the axle is in the starting position, then when resetting, turn the motor while querying the sensor until the starting position is reached.
> 1 votes

# Answer
Drive the motor at low power for some length of time in a direction until the door jams against some obstacle. Set the position sensor of the motor. Drive the motor to the desired starting position relative to the jammed position.

This violates one of the constraints of the questions, since this would run before you ran your code. However, it is simple.
> 0 votes

---
Tags: ev3, programming
---


# Question
Title: Looking for a PC controlled motor that allows for very small and precise movements
The image below is a LEGO specimen stage designed for a stereo microscope. I am looking for a recommendation for a PC controlled motors that allows for very small and precise movements.

I want use the motors attached to my specimen stage to make a very small height adjustment and then I want to send a command and capture an image from the camera-mounted to the microscope.

Here is the workflow I hope to achieve by motorizing the specimen stage:

* On KeyPress (from with C# Windows application)
    + Activate stepper motor, adjust height (z-axis) by 100-200 µm (maybe 2-4 steps in a 200 step per revolution motor)
    + Wait 200 ms (allow time for vibrations from movement to stop)
    + Activate Camera - capture an image
    + Save image (auto-named) to my folder.

Possibly using SDK like: https://github.com/pololu/pololu-usb-sdk

Any Suggestions?

Working solution: The picture with the stepper motor on the input:  Full View:

# Answer
> 1 votes
Lego gear teeth have a pitch of 3.2mm (I did not measure. Maybe trust the www?)

You want .2mm or 200 µm.

3.2mm / .2mm = 16

Worm gears provide this with 360 degrees/16 = 13.5 degrees

I'd suggest 4 motors, each driving one set of worm gears on the four corners of the platform being raised/lowered. Of course, you may not have four motors. Adding a gear train will lower the accuracy. There are 40 tooth gears, that when combined with the 8 tooth gears could work. The worm gears are tricky, they need to be braced; their symmetry is not obvious.

Interesting problem.

---
Tags: programming, motor, remote-control, 3rd-party
---


# Question
Title: How do I switch out a gear in the Cat D11 set without taking the set apart?
I have a fully completed Cat D11. Great build. (I have previously built the Bucket Wheel Excavator, the Rough Terrain Crane, Liebherr 9800, Airbus 175, etc.) Couldn't get through calibration. Did not understand I should have tested the build per step 198. (You'd think I could follow picture instructions at age 74...)

After much evaluation and checking everything I could think of, I can see in the build step 104 I put the small bevel gear ON THE WRONG SIDE of the drive gear. Obviously it is trying to drive that shaft in the wrong direction!

Does anyone have an idea how I can switch out the gear WITHOUT tearing the build down completely? I'd like to see my 75th birthday...

# Answer
> 1 votes
In Step 164 the axle the bevel gear is on becomes locked. At this step the sub assembly gets put on the main assembly and the axle is blocked by a large technic motor. Before this step, you could probably still manipulate the axle enough studs out with pliers to switch the bevel gear.

That's of course still lot of steps to reverse, but you'll notice that the entire model is built in lots of smaller sub-assemblies... so you don't need to revert each step, you can leave the sub-assemblies intact...

Alternatively, there are other ways to control the technic model than the standard app:

* brickcontroller2: you could create a profile very similar looking to the control+ interface but arrange the responding actions to accommodating for the inverted bevel gear.
* pybricks: You could create a program in python that controls the model based on input from a remote control or e.g. a PS4 controller...
* powered up app: similar to brickcontroller2 but the "official" way Lego suggests to go if the Control+ app doesn't suffice anymore...

---
Tags: technic, repair, disassembly
---


title: Wobble problem with the PF L motor

text:
# Question
Title: Wobble problem with the PF L motor
So I got my hands on a used 42095 LEGO Technic set that I wanted for a long time. After disassembling it and testing PF for the first time, I have noticed that one of the motors is extremely wobbly, to be specific the orange part, and this becomes obvious when I insert a long axle. I didn't take a look inside because I was afraid that I might damage certain part in there. For the record, the motor works fine, but it is extremely loud compared to the other one, and it makes this "vroom-vroom" sound. I suspect it may be one of the smaller gears in the inside that is misaligned and causing the wobble.

Any help how to fix that would be appreciated.

Also thank you Alex for correcting typos and other mistakes i made.

# Answer
> 3 votes
I managed to fix the problem, thanks to everyone who took the time to provide help/advice. I managed to open the motor but it is impossible to do that without damaging the clips that are holding it in place.

As for the cause of the problem itself: the lubricant that was used on the tiny white planetary gears inside wasn't distributed equally throughout the orange bearings in the carrier, which created this bump that caused the whole mechanism to shift upward whenever the motor started spinning. I removed all planetary gears and applied the excessive lubricant to all of them and reassembled the motor - which fixed the wobble, but it also fixed that nasty sound it was making.

Hopefully, this will help anyone who is suffering from the same problem, but beware: you will damage the clips. But it shouldn't be that bad.

---
Tags: motor, power-functions, repair, disassembly
---


title: What will the size of finished set be?

text:
# Question
Title: What will the size of finished set be?
How can you tell from information on the box or manual what the size of the finished set will be? I'm thinking of space needed to create and store, etc.

# Answer
Modern largest sets usually state on the box how big they are. But this isn't a case for smaller sets.

However there is another option. Based on brick dimensions it is possible to estimate the size of a set. Assuming set is built in traditional "studs up" approach:

* each stud on horizontal plane would be 8mm
* each brick on vertical plane would be 9.6mm, where each plate is 3.2mm.
> 1 votes

# Answer
## LEGO shop site

In the marketing for large LEGO sets, they typically make a big deal about advertising the dimensions. In the case of the Apollo Saturn V for example you can find the dimensions under the 'Specifications' section:

> Measures over 39" (100cm) high and 6” (17cm) in diameter.

You might also be able to find this on the set box.

## Bricklink Studio

Bricklink Studio also has a feature that displays the dimensions and weight of models. This can be found under the menu bar 'Model' and then 'Model Info'.

If you can find an existing model of the set you are looking for you can download it and import it into the software. Of course you can also make modifications to the model or build your own too.

You can import LEGO Digital Designer files into Studio as well and there is a huge collection of fan-made models of existing sets at Eurobricks.
> 0 votes

---
Tags: sets, size
---


# Question
Title: Which set contains this Bionicle part? Looks like a mohawk or some sort of blade
Which set contains this piece? I cant find anything. It looks like a big Bionicle mohawk.

# Answer
This part is 20479 (Large Figure Weapon Axe, Skull Warrior):

It is present in 3 sets from 2015:

It is used as a blade, weapon, or sharp edge in these sets:
> 4 votes

---
Tags: part-identification, set-identification, bionicle
---


# Question
Title: What are the dimensions of a LEGO brick?
What are the real world dimensions of bricks? (starting with 1x1 brick) Plates? Studs? Does LEGO think of this in metric or imperial units or something else?

# Answer
> 100 votes
This image shows the dimensions in LEGO Units. **1 Lego Unit is 1.6mm** (the thickness of the plastic wall). In those units the stud's diameter is 3 (= 4.8mm).

# Answer
> 54 votes
This image from Brickipedia should sum it up nicely:

A plate is exactly one third of a brick in height (3.2 mm as in the diagram). In other words, 3 plates stack to match the height of a brick. This is useful to know if you're short on a certain size of brick, but have enough plates of the same shape and color to cover it in height.

# Answer
> 20 votes
While LEGO uses metric nowadays, you may be interested to know that the bricks they originally copied (and bought the patent for later on) were made in the UK and thus probably used imperial measurements (although dimensions are not specified in the original patent). You may want to search for UK patent 529580 or Kiddicraft to learn more about this. There may still be remnants of that English heritage buried deep in the LEGO legacy.

Also, when LEGO started, I'm not sure what their measurements or tolerance were at the time, but they probably weren't as strict as they are now, which may account for some oddities in the system. For example, the distance between studs has been measured as 7.986mm rather than an exact 8mm.

# Answer
> 13 votes
The precise measurements with an easy to understand technical drawing is available here. A PDF with the all the dimension is available for download.

# Answer
> 10 votes
Robert Cailliau has summarized how dimensions of LEGO bricks derive from:

* The **base** measure 0.8mm (that's where the 1.6mm already mentioned derives from)
* The **play** measures 0.1mm (for additional space between pieces)
* The **height** of studs 1.8mm

It looks like the number as the same as given in other sources, but there is **disagreement about the height of a stud**. I've seen the value 1.8mm (Robert), 1.7mm (Wikipedia) and 1.6mm (answers given here). Maybe the difference is because of the "LEGO" logo on top of a stud.

# Answer
> 6 votes
These photos of side-by-side 2x4 bricks may be able to explain why people disagree as to the height of a Lego stud:

# Answer
> -2 votes
Lego had the moulds changed to metric.

From brightontoymuseum.co.uk website I learned that the stud width measures 4•87 or 4•88mm, so they are bigger than the 4.8mm space they go into, giving a tight fit & expanding the brick into the 0•1mm space around it.

Reading what is illegal for Lego, says Technic studs are not as tall, so going from a headlamp brick over them is okay when not so for normal bricks, as their studs are too tall. The side walls, & so also from stud to the edge were 1•5mm, then bricks with thinner 1•2mm with ribs. As I found they fit to older bricks better than the other bricks do looks like smaller space. On 1other website they found height to be under 9•6mm after measures stack of 100.

---
Tags: piece-information, size
---


# Question
Title: What are the longest 1×x and 2×x plates and tiles ever released?
As a follow up of this question, here is the question for plates and tiles. What are the longest 1×x and 2×x plates and tiles ever released by Lego?

When there are differences, I can think of the following categories:

* Longest brick ever included in a regular Lego set
* Longest brick ever available through other channels
* Longest brick produced ever and visible on exhibits or other occasions, but unavailable to the public

# Answer
> 8 votes
I think it's going to be the 1x12 (#60479) and 2x16 (#4282) for regular Lego plates. The next longest plain-ish plate is probably the 6x28 (#5301, 5309, 4093), but these are thicker than typical plates.

For regular tiles I think the 1x8 (#4162) and 2x4 (#87079) are the longest. Outside of the 2x? they made some odd-ball Scala tiles at 3x6 (#6934) and 8 x 20 x 2/3 (#6923). Then there's the big 8x16 (#48288, 90498).

Does Modulex count since it's a Lego company product? There were Modulex 1x16 (MX1616M) plates and 2x12 (Mx1012) tiles. They also made a huge 22x60 (Mx2420D) plate according to Bricklink. Of course these pieces are only longer in terms of studs, because of the smaller scale, the Modulex bricks are not longer in millimeters/inches. I'm curious if anyone has one of the 22x60 plates on hand to verify the bottom type? Then of course there are baseplates, I guess I assumed you weren't referring to those.

# Answer
> 5 votes
There is news (postdating the accepted answer): There are now tiles 2x6 (#69729) from LEGO available, e.g., in some Nintendo Super Mario sets.

# Answer
> -2 votes
2×16 from Guarded Inn 6067 (=10000). The floor uses a wider plate & this together.

---
Tags: bricks-and-pieces, records
---


# Question
Title: Is it possible to control Airbus H175 Rescue Helicopter 42145 via the app?
Has anyone used a Technic Hub 88012

and not the Powered Up battery box that comes with the set?

I would love to get it controlled via the app.

# Answer
> 2 votes
I don't think it would make a lot of sense, since the different functions are activated with mechanical switches. Unlike the Caterpillar D11, this set only has one motor that is shared using clutches, so an app wouldn't control much.

# Answer
> 0 votes
As long as you can get an appropriate software profile to control it with, ~~I don't see any other possible hurdles.~~

**Edit:** As Joost mentions, the accessibility of the power button could very well be an issue though.

---
Tags: technic, powered-up, remote-control, set-modification
---


# Question
Title: How to power on and adjust speed for a PU Train 88011
I'm doing a project for my kiddos.

I'm trying to find the schematics of a lego train motor 88011, I want to control them using an ESP32 through a telegram bot.

I have the ESP32 and the telegram bot working to power up or power down a led (like in this page but with some modified parts for the telegram bot https://randomnerdtutorials.com/esp32-pwm-arduino-ide/)

I was trying to understand the wiring on the lego motor, but only found some videos on 4 wired connections, these have six.

I also have no idea of what voltage these motors are, attached my hardware.

# Answer
You will need extra hardware to drive the motor since is uses high current. You won't be able to directly connect it to your ESP32 and make it move.

The LEGO hubs use a LB1836 motor driver chip (see this answer for a photo and link to data sheet). So you will need to find a breakout board with a motor driver with similar specs (example) or make your own PCB and use the same chip as LEGO.

The PWM output of the ESP32 will connect to the motor driver chip. You will need two PWM outputs to make the motor go both forwards and backwards. The motor driver chip will need to be connected to a 6-9V battery (7.2V LiPO, 6 AA, etc.). And the output of the motor driver will need to be connected to pins 1 and 2 of the motor.
> 5 votes

# Answer
There is still a simple analog connection for these motors in the Powered Up system. The wiring is similar to the older PF system in that way, except that there are now 2 dedicated signaling lines. Here's the pinout from Philo:

| Pin | Label | Function |
| --- | --- | --- |
| 1 | M1 | Motor power lead 1 (PWM controlled) |
| 2 | M2 | Motor power lead 2 (PWM controlled) |
| 3 | GND | Ground (0V) |
| 4 | VCC | Power for device electronics (3.3V) |
| 5 | ID1 | Identification line 1 / Serial data (hub -\> device) |
| 6 | ID2 | Identification line 2 / Serial data (device -\> hub) |

You should be able to drive the motor by applying pure DC voltage to the M1 and M2 pins. You can control speed using any of the common approaches to controlling DC motor speed.

In terms of voltage, anything up to 9V should be safe.
> 2 votes

---
Tags: motor, trains, powered-up
---


# Question
Title: Instructions for lego bag with 135149 (yellow and red bricks)
Please let me know if you know what set this goes with. This is everything I have.

# Answer
These bags are from 31112 Wild Lion:

This set includes 4 bags, so you appear to have everything. The instructions are available on Rebrickable.
> 5 votes

---
Tags: set-identification
---


# Question
Title: identification: strange parts in a sprue
Found this in my random parts bag.

No Lego logo's anywhere, also the shade of blue is slightly off the standard blue in the Lego colour palette. The bottoms do seem to fit quite snug on Lego studs... I do not recall how I obtained this. Can anyone identify this?

# Answer
> 8 votes
This is part # 6923 : Scala Accessories - Complete Sprue - Perfume Bottles (Belville)

in Blue it appears in : Set # 3849: Orient Bazaar

---
Tags: part-identification, clone-brands
---


# Question
Title: No spare parts in some bags within a set?
I recently purchased and built Valentine Lovebirds and Easter Rabbits Display.

While the first set contained the usual extra parts of small bricks, in 40523 the first three bags contained spares, while in bags 4–7, there wasn't a single extra part!

This does not look like coincidence.

As explain e. g. in this answer, especially with small parts, there is always the chance of error, and Lego tries to deliver rather one part too many than one too few.

Has Lego improved their packaging systems so they are sure to always exactly hit the desired count? Is this something we can expect to see more often in the future?

Has someone had no more extra parts in other sets?

# Answer
> 6 votes
Looking at the instructions, bag 4 does not seem to have any elements small enough for spares to be included.

Bags 5, 6 and 7 do, however the colors seem to be limited to green, lime and orange. Looking at the parts list on Bricklink: https://www.bricklink.com/catalogItemInv.asp?S=40523-1 none of these colors seem to be in the "Extra items" table.

So your observation is very likely correct, none of bags 4 to 7 contain extra parts.

Note that bags 4-7 correspond with the second booklet of the instructions.

Note that 1 half of a set is a very small statistical sample, hence I believe this is just an anomaly and no conclusions can be drawn from this unless more sets appear that have no spares.

# Answer
> 0 votes
Just wanted to point out the possibility that these bags usually do contain spare parts but your specific set is an example of the reason for spare parts. In other words, bags 4-7 usually do contain 1 or 2 spare pieces because there can be errors in packaging and you happened to get a packaging error and received fewer pieces than planned. Because there are spare parts you still have a full set, just without any spare pieces.

---
Tags: packaging
---


# Question
Title: Need help identifying an unopened LEGO bag - lime green and black pieces
We found an unopened bag of lime green and black pieces. Son does not remember what or where it came from which is odd because he's always eager to assemble sets when he gets them. Looks like some sort of vehicle since there is a windshield, wheels and steering with pieces that are smooth on the outside.

# Answer
> 4 votes
76899-1 Lamborghini Urus ST-X & Lamborghini Huracán Super Trofeo EVO

Based on

* Black Brick 1 x 10
* Lime Plate 1 x 6
* Lime Slope, Curved 8 x 2

---
Tags: set-identification, vehicle
---


# Question
Title: How does the play experience work in the City Missions sets?
I recently saw one of the LEGO City Missions sets:

According to the box, these sets are **"built with stories, not instructions"**. How does this work in practice?

# Answer
I saw these on the shelf recently and wondered how they worked. TLG was kind enough to send me a copy to explore.

The experiences for this set are available in the LEGO Builder app. The box itself does not come with any form of paper instructions aside from a single page directing builders to access the app:

The app allows you to select a set and explore its missions:

The build and play experience is driven by a series of "missions" inside the app:

I initially expected these sets to be a bit like a Creator 3-in-1 sets with app-based instructions and light "story" elements between certain steps based on this image from the box:

I was pleasantly surprised that there is quite a bit more opportunity for creative building here than I initially assumed. The first mission allows builders to create a couple minifigs with a few accessories. There's not a huge amount of creativity involved here, but you can mix-and-match minifig parts.

The second mission provides the build for the core element of the set and is built using regular in-app instructions. This provides the structure for future missions and steps. Here's the completed core for the space set:

The core elements for the sets feature a few play features and numerous attachment points for accessories and modifications.

Subsequent missions provide short video and text descriptions of challenges to overcome by adding or changing features of the core set. These missions may not include additional instructions:

Builders are provided with extra pieces and high-level goals for the build (e.g. rescue an astronaut floating in space). There are also ideas provided for possible minibuilds that can be added to the main build:

Once the self-guided creative modifications have been completed, builders can finish the mission and participate in an imaginative play experience (test the booster, fly to Mars, look for clues related to a crime, rescue an animal, etc),

Aside from a brief video, the missions do not include any digital play component. This isn't a series of digital minigames between building steps. There's not much to do in the app other than follow instructions, read, and watch short videos.

As far as I know, there are 3 sets available following this format. They are:

They each include a base model that can be customized with an array of parts:

## Animal Rescue

## Space

## Water Police

In terms of the play experience, these sets feel a bit like Education sets, Boost, or Robot Inventor where the builder completes a series of builds and tasks in an interleaved manner.

As far as parts go, these felt a little bit like the 2018 Builder Bigger Thinking sets, where builders are given a variety of imaginative parts and minifigs:

For my child, it was helpful to have a base to build from and then have a palette of distinctive pieces to use for customization. Here's what they came up with:

Overall, I appreciate seeing LEGO try something a bit different in the City line by making use of some of the techniques used in more educational sets. This seems like it could be a good way to get certain types of kids more involved in creative build and play experiences.
> 15 votes

---
Tags: building, sets
---


# Question
Title: What set is this? Star Wars, lots of greys, light and dark
What set do these bags belong to? It is the same Star Wars set.

# Answer
> 6 votes
75292-1 The Razor Crest (The Mandalorian Bounty Hunter Transport)

This is all from the first large photo which has the wheels (didn't see the second large photo until after the links were fixed). The small photo perplexed me for quite a while as well, so I'm just going to ignore it now.

Based on

* Light Bluish Gray Plate, Round Half 3 x 6 with 1 x 2 Cutout
* Dark Bluish Gray Plate 4 x 4 Corner
* Yellow Technic, Axle 7L

# Answer
> 3 votes
I'm a bit confused by this. I needed to squint (and zoom the image), but I can see at least 3 units of Plate, Modified 4 x 6 with Trap Door Hinge in dark bluish grey:

...plus one 60485 technic axle, 9L in yellow:

Performing a search for sets containing those parts yields set 75292-1 "The Razor Crest, but the parts list for the set does **not** include any 6x10 or 6x12 plates, nor any 4x12 plates.

There's a few sets which include several trapdoor plates plus 4x12 light bluish grey plates (millenium falcon, AT-AT, UCS super star destroyer), but none of those sets do have any 9L yellow axles.

Better photographs are needed; or, at least, clarification on the sizes of light bluish grey plates in that bag.

---

Edit: The new photographs have clarified the situation. The 6xN plates are dark grey (and not light grey), and the 4x12 plate is really two 4x6s. As @RSchulz has pointed out, this is indeed the Razor Crest.

---
Tags: set-identification
---


# Question
Title: white-coloured light brick for the iron man sets
I've recently built the Marvel Iron Man Figure (76206) which comes with a light brick to power the 'arc reactor' in the set

I find it problematic that the light brick lights up orange, rather than the white/bright blue like in the movies. The transparent blue plate doesn't do much to modify the colour. I'm also building the Hulkbuster 76210 set next, which according to online reviews has the same problem with the 3 light bricks included.

Is there a third party source where I could buy alternative or modified light bricks? Does anyone have or can produce instructions to exchange the LED in a Lego light brick?

# Answer
I'm not aware of 3rd party sellers that offer these in alternate colors, but it doesn't look terribly difficult to do yourself. There is at least one video covering the process. Here's the gist:

1. Take the base off with a screwdriver

2. Remove the original LED

3. Acquire a suitable replacement LED of the appropriate color and voltage

4. Bend and trim the leads on the new LED

5. Test and reassemble
> 13 votes

---
Tags: electronics, set-modification, lighting
---


title: Lego 42129 automatic suspension lift

text:
# Question
Title: Lego 42129 automatic suspension lift
Has anyone looked at a mod to lower the suspension on the LEGO 42129 4x4 Mercedes-Benz trail truck when the differential lock activates.

I was thinking about a few linear Actuators but never had a set with them in so I also wondered how much power they can take and apply?

Can linear actuator be operated from both ends, i.e. if you push down on the extended rod, will the lower shaft rotate or is power transfer just one way?

I hope some can help, even if it's just with info

# Answer
> 1 votes
A linear actuator cannot be operated both ways, and cannot replace a strut with a spring. It can only be driven through the gearing input to extend or retract.

---
Tags: technic, powered-up, remote-control, set-modification, control-plus
---


# Question
Title: Extend/retract speed of linear actuators
I am trying to find out if the linear actuators (small, large and XL) have a fixed number of rotations on the bottom axle connector in order to extend them fully?

I am guessing the small LA will take fewer turns?

# Answer
> 9 votes
I found Sariels video here helpful:

https://www.youtube.com/watch?v=A23yh-enhyI

Sariel states that all 3 LA's extend and retract at the same speed. Several sources state that the L linear actuator takes 26 revolutions to extend to its full 5 studs, so the small LA will take 15.6 revolutions to extend to its full 3 studs and the new XL linear actuator will take 41.6 revolutions to extend to its full 8 studs.

---
Tags: technic, piece-information
---


# Question
Title: What is this brick with a round back and a stud on the side used for?
I haven't seen this part before. What is it? What is it used for?

# Answer
> 16 votes
This part is 3386 Plate 1 x 1 x 2/3 Half Round with Side Stud.

I recently encountered this part for the first time and wanted to share more about it as it is new to me and looks very useful. It was launched in 2023 and appeared originally in 3 speed champions sets:

In terms of the height and side stud placement, it is similar to 87609 and 99206

It's even a bit like the classic Erling brick when the brick is used on it's side:

This is one of the smallest brick-like parts available that provides two studs at 90 degree angles from one another. It fills a role somewhat similar to the smallest brackets, 36840 and 36841:

This part shares its footprint with 24246 Tile Round 1 x 1 Half Circle:

It does have some unique advantages. It's very easy to sneak this part in where it would otherwise be difficult to create a studs out connection. Here are some examples from the first wave of sets:

Another advantage of these parts is that they can be used to recreate the 5 plate tall bricks with studs on side in a way that should be usable in most contexts where these elements are needed:

The geometry of these parts also makes them useful for microscale building. Here's a quick example of a train car that uses these elements to attach the wheels:

The rounded back of the part also allows it to be used at varying angles as demonstrated in this quick X-wing design:

This looks like a part that could open up a number of new building opportunities.

Here's a final clever example of this part being used upside down to create a tiny toilet on the Concorde:

---
Tags: piece-information
---


# Question
Title: Bags in Lego 21029 Buckingham Palace Architect
Does anyone know how many bags are in Lego set 21029 Buckingham Palace Architect set Thanks in advance

# Answer
Based on this video there are 5 unnumbered bags with few non-packed plates inside.
> 4 votes

---
Tags: architecture
---


title: Please identify this green pin

text:
# Question
Title: Please identify this green pin
I bought the 42153 set yesterday and I got this green rare pin in bag 1.

How can this Technic pin be used?

# Answer
> 4 votes
I assume you mean this pin: https://www.bricklink.com/v2/catalog/catalogitem.page?P=65826

Which was first introduced in the Spike Essential set, but is currently also present in a couple of other sets, e.g. the Technic set NASCAR Next Gen Chevrolet Camaro 42153, as you mentioned but also the Volkswagen T2 Camper Van (VW Bus) 10279

Its purpose is to connect system elements with Technic elements, it serves a very similar purpose as the half pin

https://www.bricklink.com/v2/catalog/catalogitem.page?P=4274

with the main difference being that the stud on the pin is inverted. Rather than enabling to connect a system elements with the studs **away** from the Technic element, with the green pin, you connect the system element with the studs **toward** the element.

---
Tags: part-identification, technic
---


# Question
Title: Are there any flat plates with beveled or sharp edges?
I'm currently making a functional minifigure-scaled escalator that ideally move like this. Progress has been made on both the stair slope and staircase design (both respectively pictured below), and now I'm working on a sort of guide for the staircase to transition into flat platform.

However, I've come to an issue regarding the height of the guide being 1 plate thick, as I've yet to find any flat plates or bricks of plate width with the appropriate bevel to prevent the staircase shafts from getting snagged. Currently, the only "beveled" plates that I could think of is the 22385 pentagonal plate, and the 15070 modified plate with tooth and its other variants.

Are there any other kinds of "beveled" bricks should I know of or any legal building techniques that can create a sturdy plate-width edge or slope that could be utilized here? Either way, I want a result such as this image (note the red plates and the drawn-in edge):

Here is another view of the overhang, and also beveling attempt using the pentagon plate:

It is paramount that this guiding overhang is 1 stud in width or shorter, 1 flat plate tall, and built using only legal techniques.

I am also aware of the dedicated escalator piece but I won't be using it due to the complex nature of my build.

EDIT: This might be an illegal technique, but I might have found a method for sloping, which utilizes a panel atop 1x1 brick with stud on the side and a 1x1 headlight brick joined at the side. This is the base, with the two snot pieces forming an offset stud arrangement on top.

And this is the base with the panel connected with the two studs, making it slanted.

While I have tested this with my available bricks and it works, I still don't know if it's a legal building technique or not, so please inform me.

EDIT 2: I was informed by @Sander De Dycker that this building method is illegal, as the top studs are slightly further away than normal. However, since this slanted panel is very close to my desired outcome in terms of angle (280 degrees as Stud.io informed), I am in search of legal building techniques that produces the same result.

# Answer
**Update:** After testing out the design with physical bricks, I have come to the conclusion that my iteration using the 22385 pentagonal plate at a jumper offset would have created a serviceable bevel to have the staircase shafts guided up with relative smoothness. The design is as below:
> 0 votes

# Answer
The thinnest curved lip I can think of is Panel Curved 2 x 1 x 1 :

You'd still have to accommodate for the axle hole, but there appears to be room for that in your design (possibly just held by gravity).
> 2 votes

# Answer
I do not believe smaller sloped elements than these exist:

https://www.bricklink.com/v2/catalog/catalogitem.page?P=11477

And some wedged variants:

https://www.bricklink.com/v2/catalog/catalogitem.page?P=29119 https://www.bricklink.com/v2/catalog/catalogitem.page?P=29120

(1 module x 2 modules x 2 plates) 2 plates high overall but on average a little less.
> 1 votes

# Answer
See 50950 Slope, curved, 3x1 and 61678 Slope, curved, 4x1.
> 0 votes

---
Tags: technic, piece-information, building, moc
---


# Question
Title: How can I build a Lego slope of a rough 50 degree angle with preferably legal building techniques?
I am currently building a functional Lego minifigure-scaled escalator that can transition from flat platforms to stairwell. My first iteration for its guiding rail includes a slope of ~39.5 degree inclination as thus:

And here is the first staircase which the guiding rail is designed around:

But now I've been looking into a newer staircase design that has an additional plate of thickness, and its slope is ~50 degrees as measured in Stud.io. Here are views of the staircase design with the guiding bars colored red:

And here are versions of the slope with attempts of hinge bricks and SNOT to uphold the slope angles:

Note that both slopes are not properly aligned with the studs regardless of hinge bricks or Technic connector pegs. On the left design, the colored bricks (blue is of the slopes, and green is aligned with the studs) had an offset that disallow peg connections; and on the right design, the gap between the hinge brick and the SNOT brick is actually thinner than a plate.

Is there any way of building a framework for this 50 degree slope? Preferably a legal method that produces minimal stress due to the technical nature of this build?

Please note that I have limited bricks at my disposal to physically test this out, and I don't intend to use Lego's dedicated escalator piece as it is incompatible with any of my designs.

# Answer
You can always invert your "escalator piece" to use as a base as it will make exactly same angle. Then it is up to you how you want your guiding rail to be attached. Here's one idea:

Please note both Blue pieces may not alighn to stud/half-stud grid.
> 3 votes

# Answer
The bar elements in your step part are vertically separated 3 plates and horizontally 1 module which is 2.5 plates. So the exact angle (rather than approximately measured) is atan (3/2.5) = 50.1944289 degrees.

You might want to consider designing a step part where the bars are separated vertically by 4 plates and horizontally by 3 plates (or vica versa) which gives a slightly steeper angle (53.13 degrees) so that the sides of the triangle describing the main stairs are in ratio of 3-4-5 (pythagorean triangle). As a bonus the multiple of 5 plates will correspond nicely with a multiple of 2 modules...
> 2 votes

---
Tags: technic, building, moc, angles
---


# Question
Title: Does the 10309 Succulents set contain only non-unique bricks?
First-time poster here: I write on innovation topics, have been Lego-infatuated for maybe 45 years now. My kid and I were assembling the 2022 succulents kit (#10309) and I noticed a piece that looked like a Robin Hood-type hat. Turns out it was (Forestman hat - 6395137). I've since disposed of the box but I distinctly remember it saying somewhere that no net-new pieces were developed for that set. Can anyone confirm this? It's the jumping-off point for a post on compositional innovation.

# Answer
I don't see anything on the box indicating that there are no new parts in this set:

I also briefly flipped through the instructions and didn't see a mention of this. However, I do not believe that there were any new molds created for this set. We can see this by looking through the Rebrickable inventory.

While it does not appear to me that any new molds were made for this set, there were several recolors. For example, both of these elements appeared for the first time in this set:

43898 in Bright Light Orange

24946 in Yellowish Green

As of May 2023, at least one element has only been used in this set:

43898 in Coral

This set could still support your thesis. Injecting a new color of plastic into an existing mold is much cheaper and more economically efficient than machining a new mold, and demonstrates the sort of compositional innovation you are discussing.
> 6 votes

---
Tags: piece-information
---


# Question
Title: This is a AT-ST but I cannot identify what set it goes to
This is a AT-ST but I cannot identify what set it goes to. Can you help me?

# Answer
This is from

8038: The Battle of Endor

Keypart : Dark Bluish Gray Plate, Modified 6 x 8 Trap Door Frame Horizontal
> 6 votes

---
Tags: set-identification, star-wars
---


# Question
Title: A Star Wars thing, but what set is it from? A sphere with legs?
A Star Wars thing but what set is it from?

# Answer
This is

75142: Homing Spider Droid

Keyparts
> 1 votes

---
Tags: set-identification, star-wars
---


# Question
Title: Would this be a Star Wars ship. What set would it go to? Greys but with dark greens
Would this be a Star Wars ship. What set would it go to?

# Answer
> 2 votes
This is from :

75168: Yoda's Jedi Starfighter

Keypart

---
Tags: set-identification, star-wars
---


# Question
Title: Can you help with the set identification for these items? Symmetrical greyish wings, and tan/brown internals
Can you help with the set identification for these items?

# Answer
> 3 votes
The left two assemblies are from

8095: General Grievous' Starfighter

keypart:

The right assembly is from : 75234: AT-AP Walker

Keyparts :

---
Tags: set-identification, star-wars
---


# Question
Title: Got this at a sale. What set is it for? Lots of greys with 4 legs
Got this at a sale. What set is it for? Some one knows.

# Answer
This is from

7869: Battle for Geonosis

Keypart
> 4 votes

---
Tags: set-identification, star-wars
---


# Question
Title: Can you identify these 2 retro bricks? A red piece with notch and steps, and a green circle
No idea about these parts. The green part is roughly 5x5, 6-01 code and old school Lego brand written on it. The red part has a notch and what kind of looks like internal steps. Thanks!

# Answer
1st is a train part, Plate, Modified 1 x 2 with Steam Engine Cylinder, Round Surfaces, Interior Grooves

2nd is Fabuland Trash Can Lid 5 x 5
> 9 votes

---
Tags: part-identification, piece-information, vintage, fabuland
---


# Question
Title: What are these magnetic LEGO-like bricks?
Can anyone identify these? The tin they are in is dated around 1967 so bricks might be of a similar age. They are magnetic. Any help greatly appreciated.

# Answer
According to this article these are called "Bombo Magnet".

> Bombo Magnet-1963.
> Bricks made of a metal plate with studs, a magnet, and its plastic cover. The plastic "grid" on the underside leaves exactly room for the elevations of the upper metal plate ensuring that bricks can be built precisely on top of each other. First presented at the 14th Toy Fair in Nuremberg. Made by: BOMBO GmbH in Bad Honnef am Rhein, Germany.
> 9 votes

---
Tags: piece-information, clone-brands, vintage
---


title: Direct command to set EV3 motor speed

text:
# Question
Title: Direct command to set EV3 motor speed
I am trying to set a EV3 motor's speed and start it remotely using a direct command. Using the resources LEGO MINDSTORMS EV3 Communication Developer Kit (page 24) and LEGO MINDSTORMS EV3 Firmware Developer Kit (page 53) I've came up with the following (Kotlin) code to create the command:

```
ByteBuffer
    .allocate(18)
    .order(ByteOrder.LITTLE_ENDIAN)
    .putShort(16)
    .putShort(0)
    .put(0x80.toByte())
    .putShort(0)
    .put(0xA5.toByte())
    .put(0)
    .put(0b01)
    .put(leftSpeed.toByte())
    .put(0xA5.toByte())
    .put(0)
    .put(0b10)
    .put(rightSpeed.toByte())
    .put(0xA6.toByte())
    .put(0)
    .put(0b11)

```

However, the EV3 behaves really unpredictably, with some speed values (the range is -100 to 100) flipping the polarity, some even crashing the OS.

# Answer
> 3 votes
The parameters must be encoded. See section 4.2 in the *Communication Developer Kit* and section 3.4 in the *Firmware Developer Kit*.

Here are the referenced macros from `bytecodes.h`:

```
//        MACROS FOR PRIMITIVES AND SYSTEM CALLS

#define   PRIMPAR_SHORT                 0x00
#define   PRIMPAR_LONG                  0x80

#define   PRIMPAR_CONST                 0x00
#define   PRIMPAR_VARIABLE              0x40
#define   PRIMPAR_LOCAL                 0x00
#define   PRIMPAR_GLOBAL                0x20
#define   PRIMPAR_HANDLE                0x10
#define   PRIMPAR_ADDR                  0x08

#define   PRIMPAR_INDEX                 0x1F
#define   PRIMPAR_CONST_SIGN            0x20
#define   PRIMPAR_VALUE                 0x3F

#define   PRIMPAR_BYTES                 0x07

#define   PRIMPAR_STRING_OLD            0
#define   PRIMPAR_1_BYTE                1
#define   PRIMPAR_2_BYTES               2
#define   PRIMPAR_4_BYTES               3
#define   PRIMPAR_STRING                4

#define   PRIMPAR_LABEL                 0x20

#define   HND(x)                        (PRIMPAR_HANDLE | (x))
#define   ADR(x)                        (PRIMPAR_ADDR | (x))

#define   LCS                           (PRIMPAR_LONG | PRIMPAR_STRING)

#define   LAB1(v)                       (PRIMPAR_LONG | PRIMPAR_LABEL),((v) & 0xFF)

#define   LC0(v)                        (((v) & PRIMPAR_VALUE) | PRIMPAR_SHORT | PRIMPAR_CONST)
#define   LC1(v)                        (PRIMPAR_LONG  | PRIMPAR_CONST | PRIMPAR_1_BYTE),((v) & 0xFF)
#define   LC2(v)                        (PRIMPAR_LONG  | PRIMPAR_CONST | PRIMPAR_2_BYTES),((v) & 0xFF),(((v) >> 8) & 0xFF)
#define   LC4(v)                        (PRIMPAR_LONG  | PRIMPAR_CONST | PRIMPAR_4_BYTES),((ULONG)(v) & 0xFF),(((ULONG)(v) >> (ULONG)8) & 0xFF),(((ULONG)(v) >> (ULONG)16) & 0xFF),(((ULONG)(v) >> (ULONG)24) & 0xFF)

#define   LV0(i)                        (((i) & PRIMPAR_INDEX) | PRIMPAR_SHORT | PRIMPAR_VARIABLE | PRIMPAR_LOCAL)
#define   LV1(i)                        (PRIMPAR_LONG  | PRIMPAR_VARIABLE | PRIMPAR_LOCAL | PRIMPAR_1_BYTE),((i) & 0xFF)
#define   LV2(i)                        (PRIMPAR_LONG  | PRIMPAR_VARIABLE | PRIMPAR_LOCAL | PRIMPAR_2_BYTES),((i) & 0xFF),(((i) >> 8) & 0xFF)
#define   LV4(i)                        (PRIMPAR_LONG  | PRIMPAR_VARIABLE | PRIMPAR_LOCAL | PRIMPAR_4_BYTES),((i) & 0xFF),(((i) >> 8) & 0xFF),(((i) >> 16) & 0xFF),(((i) >> 24) & 0xFF)

#define   GV0(i)                        (((i) & PRIMPAR_INDEX) | PRIMPAR_SHORT | PRIMPAR_VARIABLE | PRIMPAR_GLOBAL)
#define   GV1(i)                        (PRIMPAR_LONG  | PRIMPAR_VARIABLE | PRIMPAR_GLOBAL | PRIMPAR_1_BYTE),((i) & 0xFF)
#define   GV2(i)                        (PRIMPAR_LONG  | PRIMPAR_VARIABLE | PRIMPAR_GLOBAL | PRIMPAR_2_BYTES),((i) & 0xFF),(((i) >> 8) & 0xFF)
#define   GV4(i)                        (PRIMPAR_LONG  | PRIMPAR_VARIABLE | PRIMPAR_GLOBAL | PRIMPAR_4_BYTES),((i) & 0xFF),(((i) >> 8) & 0xFF),(((i) >> 16) & 0xFF),(((i) >> 24) & 0xFF)

```

Values withing the range 0 to 31 can essentially be passed directly since `PRIMPAR_SHORT` and `PRIMPAR_CONST` used in `LC0()` are both 0 (values -31 to -1 can also be used as LC0 but need to be bitwise and-ed with 0x3F). But since the speeds can be +/-100, they need `LC1()` which requires two bytes.

So something like this?

```
ByteBuffer
    .allocate(20)
    .order(ByteOrder.LITTLE_ENDIAN)
    .putShort(18) // command size
    .putShort(0) // message counter
    .put(0x80.toByte()) // direct command, no reply
    .putShort(0) // globals/locals
    .put(0xA5.toByte()) // opOutput_Speed
    .put(0) // LAYER=LC0(0)
    .put(0b01) // NOS=LC0(1)
    .put(0x81).put(leftSpeed.toByte()) // SPEED=LC1(leftSpeed)
    .put(0xA5.toByte()) // opOutput_Speed
    .put(0) // LAYER=LC0(0)
    .put(0b10) // NOS=LC0(2)
    .put(0x81).put(rightSpeed.toByte()) // SPEED=LC1(rightSpeed)
    .put(0xA6.toByte()) // opOutput_Start
    .put(0) // LAYER=LC0(0)
    .put(0b11) // NOS=LC0(3)

```

---
Tags: ev3, programming
---


# Question
Title: How I can connect the LEGO SPIKE Prime hub via Bluetooth in Visual Studio Code using the pybricksdev library?
I'm trying to send some data from the hub to the terminal for some debug. But I can't figure out how I can connect the hub via Bluetooth to my PC. I tried to look in the API documentation and maybe I found something but I'm not sure.

# Answer
The easiest way to use `pybricksdev` is as a command line tool. I recommend using pipx to ensure that your are always using the latest version of `pybricksdev`.

Assuming you have already installed `pipx` and you have a terminal open in VS Code in the same directory as the script you want to run, run the following command:

```
pipx run pybricksdev run ble my_script.py

```

Where `my_script.py` is replaced with the actual name of the script you want to run.
> 1 votes

---
Tags: programming, bluetooth, spike-prime, pybricks
---


# Question
Title: Correct axle rotation of partially built LEGO Cat D11 Bulldozer (42131)?
Page 173, Step 205, of LEGO Cat D11 Bulldozer (42131) instructions has a step to attach two sub-assemblies. What is the correct rotation of these two axles? Is it correct if they rotate in opposite directions?

# Answer
> 3 votes
I don't have this set, so my answer is based on online instructions for this particular set.

**TLDR**: Brown axles are supposed to spin in opposite directions. Long answer below.

Step 105 has two sub-assemblies attached - the ones with back axles seen on bottom left. Each of these axles drives the brown axles - one is clearly seen on bottom right and another is barely seen on top left.

Now moving forward to Step 116 we can still see both black axles present here, now with few more parts attached in between steps. Each axle has a grey T16 gear which sits rigidly on each axle (each gear will rotate together with its axle). In between both grey gears there are three more T16 in red. Now these are different - they move independently from the axle they are placed on, where none of yellow axle rotation impact any of red gears (until one of them is engaged via gearbox, but this is irrelevant now). In such setup these three gears connect both grey gears, meaning if we turn one of two black axles both would rotate. Since there are 5 gears in this gear train such combination would result in both axles spinning in the same direction. This would then transfer the rotation to tan T12 gears which, based on the way they are placed (same direction towards front of the model), would result in both brown axles to spin in opposite directions.

If you follow further down the instructions (steps 529 and 627) you can find that few more gears are attached to each axle further down the line. This would result in two connection points, used by next function, to spin in the same direction.

---
Tags: technic, motor, instructions, repair
---


# Question
Title: Identify this set: brown and tan bricks and plates
What set do these parts go to? There is no bag number. Three different shades of Brown.
Two are 2x6 and one is 6x6

# Answer
> 2 votes
Based on:

* 15397 Plate 3 x 3 cross in reddish brown,
* 30137 Brick 1 x 4 with log profile, and
* 3958 Plate 6 x 6 in reddish brown,

This is set "Bricks bricks bricks", either 10717 or 11717.

---
Tags: set-identification
---


# Question
Title: Identify this set: yellow and light grey plates
I would like to find what set these are for. Yellow, light gray, black, white. No bag number.

# Answer
Based on:

* 4162 tile 1 x 8 white, and
* 50305 wedge plate 3 x 8 yellow

This is set 6912 Super Soarer.
> 3 votes

---
Tags: set-identification
---


# Question
Title: What set would contain a bag of mixed white and light gray peices?
This bag only contains white and light gray LEGO pieces with a deep white door and window.

What set does it belong to?

# Answer
This belongs to the set 10698 Large Creative Brick Box

Key parts:

Newer fence 1x4x2 (15332) in White

1x6x2 arch (12939) in LBG

2x4 brick (3001) in LBG
> 1 votes

---
Tags: set-identification
---


title: Need to find the set these belong to

text:
# Question
Title: Need to find the set these belong to
Need to find the set these belong to. Blue octagon, a shooter, mostly black. And bananas!

# Answer
This belongs to Gorzan's Gorilla Striker (70008)

Identified by combination of following elements:

Dark Azure Plate, Modified 10 x 10 Octagonal with 6 x 6 Open Center. Dark Azure is the only shade of blue this part exist in, event though on a picture it looked like to be blue.

Projectile Arrow, Liftarm Shaft with Hollow Yellow Rubber End
> 2 votes

---
Tags: set-identification
---


title: What set do these LEGO pieces belong?

text:
# Question
Title: What set do these LEGO pieces belong?
What set do these LEGO pieces belong to? Mostly blacks and dark gray with some clear. Two different size tires and a black door frame.

# Answer
> 1 votes
Set 10698 again

Keyparts:

4x12 plate (3029) in DBG

Small tire (87697) in Black

Large tire (58090) in Black

---
Tags: set-identification
---


title: Radius of the 45 degree elbow piece

text:
# Question
Title: Radius of the 45 degree elbow piece
What is the inner/outer or mid radius of the 45 degree arc the following element makes?

https://www.bricklink.com/v2/catalog/catalogitem.page?P=65473

I tried to align several of the elements in 90 and 180 degree arcs in stud.io, the end of the arc never seems to align with any modules, so I'm inclined to think the radius is nonsensical. Is there any way two or more of these elements can be combined so the open ends align with in system modules?

# Answer
After a bit of fiddling in LeoCAD, I can confirm that the mid radius (i.e. the distance from the center of the torus to the axis of an axle) is 3.5 studs plus 2 LDUs (equal to 3.6 studs, or 72 LDUs).

Consequently, the inner radius is 2.6 studs (or 52 LDUs), and the outer radius is 4.6 studs (or 92 LDUs).

Note that the odd offset (2 LDUs / 0.1 studs) is half of the "lip" of a headlight brick, or half the height of a stud's cylinder. There are techniques to achieve a 2 LDU offset; see e.g. this question. Here's a possible assembly, just to demonstrate:

---

Edit: it has been noted that 72 LDUs is also the height of three bricks. This allows to, for example, align a 2x2 round tile using brackets like so:
> 7 votes

---
Tags: size
---


# Question
Title: EV3 Education does not recognize NXT ultrasonic sensor
How do I get the NXT ultrasonic sensor to work in the *Education EV3 Classroom* application?

* OK: I have connected a **NXT ultrasonic sensor** to the input port 1 of an EV3 control brick.
* OK: For testing, one motor is connected to port B.
* OK: In the EV3's "port view", I see that port 1 is reported as `1:NXT-US-CM`.
* OK: In the EV3's "port view", I see that port B is reported as `B:L-MOTOR-DEG`.
* OK: A simple program in the *EV3 Home Edition* works: the motor turns according to the sensor output.
* **Problem:** A simple program in the *Education EV3 Classroom* application does nothing. The application shows only the motor is connected. The ultrasonic sensor is not shown.

*EV3 Home Edition:*

*Education EV3 Classroom* application:

# Answer
> 3 votes
*EV3 Classroom* only supports LEGO EV3 sensors. It does not work with NXT or 3rd-party sensors.

---
Tags: ev3, education, sensor-ultrasonic
---


# Question
Title: From which LEGO set are these brown and green parts?
These LEGO parts are mostly brown tones with some green. They look like they go together but I don't know how and don't know the set they would belong to. I hope you can help.

# Answer
These appear to be largely from set 21160 - The Illager Raid :

But there are several parts in there that did not come from that set, eg. :

So it appears some foreign parts snuck in, and neither is the set complete.
> 6 votes

---
Tags: set-identification
---


title: Which set is this part 6082 from?

text:
# Question
Title: Which set is this part 6082 from?
Which set this is from, part number is 6082 or 60052.

# Answer
This is Rock Panel 4 x 10 x 6 Rectangular (BURP) with Marbled Dark Green Pattern and it has been included in three sets.
> 8 votes

# Answer
The set is 7036-1 one of the three sets containing the part.

https://www.bricklink.com/v2/catalog/catalogitem.page?S=7036
> 3 votes

---
Tags: part-identification, set-identification
---


# Question
Title: Identify this set - dark blue plates, trans-blue canopy, trans-yellow & trans-red bits
526R6 - Lego bag with large 5 then box under with 526R6 under it...

Unsure what this bag makes, also need instructions.

526R6 - Lego bag with large 5 then box under with 526R6.

There are also 2 smaller bags inside but 1 has yellow, red, and grey pieces.

Also bag says 2015 The Lego group and also in another spot has what I believe to just be a generic bag number 135149.

Any help is extremely greatly appreciated!!!

I have included a picture this time as well. Thanks again!

# Answer
The minifigure seen in the photograph, which looks like a "black iron man", is quite unique - it's sh258 "Warmachine" and it appears only in one set: 76051-1 "Super Hero Airport Battle".

Note also the trans-darkblue canopy, and the trans-black tower windows.
> 5 votes

---
Tags: set-identification
---


# Question
Title: How can I add 1x4 tile stairs to my octagonal gazebo model?
How can I add 1x4 tile steps to the bottom of the front opening in the gazebo model below? The base of the gazebo is a 10x10 octagonal plate (part 89523). I have tried using wedge and round plates but the studs on the base plate are too wide apart to fit the plates.

I want to emulate the stairs as shown here:

(Source: https://www.flickr.com/photos/kurt-b/52681755904/. Author: Kurayba. License: CC BY-SA 2.0)

# Answer
Add a single jumper plate, in the position shown below, rotated 45 degrees in relation to the direction of the studs of the octagonal plate. Connect plates as needed (shown below: a 4x4 plate). Add tiles on top of the plate(s) if needed.
> 9 votes

---
Tags: building, design, moc, size
---


# Question
Title: How can I export EV3 Classroom app project on Android tablet version of the app?
I need to submit EV3 code to enter a coding competition. The program is written in the EV3 Classroom app on a Samsung Android tablet. I tried to look for the file with `.lmsp` extension but cannot find it anywhere. Any ideas?

# Answer
I'm afraid there isn't a way to do this on Android. The SPIKE app has a *SHARE* button on the *My Projects* page but the EV3 app doesn't seem to have this feature.

As an alternative, you could try taking screenshots of the program and submit them.

It may also be possible to find the files using the Android debug program (`adb`), but I couldn't file the files anywhere using a file browser on Android.
> 2 votes

---
Tags: ev3
---