# Question
Title: Is there a way to keep large plates together more efficiently?
Whenever I'm building a baseplate for something such as a skyscraper, every time I put larger-scale pieces (such as an 8 by 4) onto the larger bottom piece (i.e. 16 by 16), there is always space under the smaller piece and it never seems to flatten itself completely, no matter how hard I push on it. This results in imbalances in whatever goes on top of the plate. I don't want to damage the plates with a hammer, but is there another technique that I can use to keep it down?

# Answer
> 5 votes
This isn't my personal experience, but I have seen and heard people use **rubber hammers** for fixing larger plates onto baseplates, which shouldn't be all too different from fixing them onto normal plates.

Those are a classic homeworking tool, commonly used pretty much for the "real world" equivalent of what you're doing, fixing floor tiles and cobblestones into place. They should be soft enough when applying force over a flat area as long as you don't hammer away like a madman. For additional protection **you could possibly also put a piece of cloth over the plates**. It's probably still more effective and lesss straining than using your hands to hammer or your thumbs to press.

In general though, it's also not a bad idea to try and **avoid sticking too many big plates onto each other**, as even if you get them pressed together really tightly, it can lead to bending of the entire model when done over a larger area, which is especially noticeable when having a flat ground stand that then...isn't flat anymore. Some of the "thicker" Architecture sets like Trafalgar Square or Robie House exhibit this problem. Try to thin it out when you can or use baseplates for the bottom layer, which are a lot more flexible in themselves.

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Tags: design, piece-usage, tools
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# Question
Title: Is there a duplicate/copy paste function in Lego Mindstorms Ev3 programing?
I remember, when I first started out Lego Mindstorms, there was a copy and paste (duplicate) blocks function. I could highlight and right click the blocks then press on duplicate to make another copy of it. This was extremely useful if I needed the robot to do something almost like another line of code, albeit with some minor changes. Is there something resembling this function now or did it never exist (my mind might be playing tricks on me)?

I am using the Lego Mindstorms Ev3 Student Edition by LabView.

# Answer
> 2 votes
I don't remember any context menu that pops up on right-click, but `CTRL`+`C` to copy highlighted blocks and `CTRL`+`V` to paste them works.

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Tags: ev3, programming
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# Question
Title: Where to start with a custom firmware for the NXT
In the process of hardware hacking with my NXT 2.0 I Found no easy way to connect the device as a USB storage device. Is there a specification that states how the NXT interacts over USB, or should I just RE the firmware?

I have experience with coding in C, compiling, linking, etc. So I’m not completely new.

I know the firmware is open-sourced, but as others have written their own firmware, and since the codebase is pretty big, I’d like to gain opinions on where to start modding the firmware.

# Answer
The best resource I have found for compiling NXT firmware is http://nxt-firmware.ni.fr.eu.org/.
> 1 votes

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Tags: nxt, programming
---


title: How should castle doors be attached?

text:
# Question
Title: How should castle doors be attached?
I'm trying to plan the pieces I'll need for a castle door. I know I need 2 of these doors. Based on the part list for Adventurers Tomb set, it looks like I'll need several shutter holders, right? Is there a way to fill in the curves around the top so the front is solid?

# Answer
The Adventures Tomb 2996 set you mentioned uses shutter holders to mount the door and a 1x6x1 arch to cover the space behind the doors:

It is also very common to use a 1x6x2 arch, as was done in Dark Fortress Landing 8802:

As I mentioned in another answer, these clips generally attach to the back of the door, not the side. The geometry is more complicated to completely fill if you want to have the doors hinge from the side.
> 6 votes

# Answer
I have those doors, and you're right about the shutter holder bricks, which are pretty fragile. The doors each cover half the space under a 1x6x2 arch. Besides the shutter snaps, the only connection point is the stud/doorknob.
> 4 votes

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Tags: design, castle
---


# Question
Title: Attaching a ring-like handle to a castle door
I'd like to attach a round metal looking handle to a castle door such as this one.

I did a search for 'ring' on Bricklink and found the life preserver.

Would this work, or are there better options? I wonder if I could just thread a key ring through a technic brick.

# Answer
I agree with Alex. There's no reason to settle for *a ring*, when you could use *the ring*.

Here's one way to attach it if you want the ring to look like it is hanging down from the door:
> 18 votes

# Answer
Perhaps Minifigure, Utensil Ring 1 x 1 will be a better fit as it is slightly larger than a stud, while life preserver is 3-4 studs in diameter.

Here how it looks when attached to doors you've mentioned:
> 11 votes

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Tags: design
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# Question
Title: How to prevent my connected axles from falling apart?
In my EV3 robot, I have two rear axles connected to each other using this part mounted like this:

\[

The problem with this construction is that after a while of driving, the axles disconnect like this:

Is there a sensible way to prevent this from happening?

# Answer
> 6 votes
You can attach couple of half bushes or full bushes on inner side of the axle near Technic beam like on the other side you have done with a gear. If axle is still trying to slide - fill in the entire inner axle part with bushes.

Here is picture of suggested fix. Here you can see extra half bushes added to fix the axle the same way gear fix the other axle from moving outwards.

# Answer
> 2 votes
If you want to stick to your current design (despite its obvious flaws), then here's another idea. Let's go!

As you can see, I tried to rebuild the crucial part of your framework.

Alright. Now two things I've noticed. You're using axles with stop. And there's some play between the bush and the wheel.

Okay, firstly on axles with stop.

Here's two pairs of axles. The two axles with stop are on top, the bottom ones are without stop bit. See that the top ones don't touch each other? See the gap? That's because of the stop and the fact that the wheel has no counterbore. Can you spot the inner rim on the liftarm (blue arrow)? That's what the wheel lacks.

So what about it? Well, here's the problem. Let's take a yellow connector and make them one long axle. But, remember the gap between them?

Once you push them into the connector -all the way in till they 'hit the ground'- you will flex the red and yellow liftarms inwards. Maybe just a tad, but still. They will sure flex back, but because of the stop on the axle the wheel can't pop off. So the axle gets pulled out of the connector instead.

Next about the connector. You chose a connector with a pinhole. This piece is three studs long. So your wheel is now off by one stud. And I think you've therefore adjusted the wheel. That's why we can see this play.

# Answer
> 0 votes
If the application of (half)bushes as mentioned in Alex's answer don't cut it, consider building a frame that holds the ends of the grey axles together, like so:

# Answer
> 0 votes
I think the real problem is the design and the way you used the motors.

If you motorize only one of the wheels with the medium motor to get the other one to move, then the one that's closer to the motor may go faster and you'll probably end up with a slight deviation to the left, which also includes the other wheel snapping off.

Also, using the large servo motor just to steer a few degrees is not worth it, as the servo motor goes faster than the medium motor ~~and you have **two** servo motors, so I recommend that you redesign your car and individually motorize the two back wheels.~~ and since you said that you only have one servo motor, you should put one between the two axles to keep them together *and* to motorize both. Use the medium motor for steering instead.

See this car for ideas. Building instructions are included.

---
Tags: ev3, technic, building, vehicle
---


title: Castle Siege: Flaming arrows

text:
# Question
Title: Castle Siege: Flaming arrows
I'm trying to think of ways to defend my LEGO castle. Is there a way I can shoot some flaming arrows into the hearts of the invaders? Maybe some burning oil?

# Answer
Burning oil is the easier of the two, since the basic flame elements

can connect into a realistically looking stream of liquid fire:

Depicting individual arrows is a lot harder due to the absence of a single arrow piece (aside from the proportionally way oversized harpoon piece), and adding a flame piece is even harder. Your best bet would probably be adding a flame piece, any of the several sizes available to a shield:

Or use a flame piece with a shaft as a combined arrow and flame:

But if 3rd party pieces are not out of question, you can get some convincing results, in this case with Brickarms arrows:
> 10 votes

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Tags: design
---


title: How to make a street-light style torch

text:
# Question
Title: How to make a street-light style torch
I need to light up my streets so the citizens of my castle can get around at night. I'd like to do something like this:

From Etsy listing:

From https://www.pixtastock.com/illustration/58823117:

(I guess in some places they call this a 'sconce')

I looked around on Bricklink and the closest I found was this lantern below. But it looks like it only attaches to a hand, so I can't put it on the wall. Any suggestions?

# Answer
Tree Palm Top was used as lanterns in old pirate sets, for example 6285
> 12 votes

# Answer
1989's Eldorado Fortress from the Pirates universe had torches made from part 3959 with a single transparent stud on the "top", with the entire assembly pushed into an Erling brick.

You can get a similar effect by clipping a lightsaber hilt piece to the wall or putting it onto a post. Just add a suitable flame piece (or simple stud) coming out of one end. For a recent handheld version of this (could be easily adapted to a stationary lamp), see Ninjago set 70671, Lloyd's Journey.
> 9 votes

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Tags: design, castle
---


# Question
Title: Mindstorms NXT NXC RemoteStopProgram fails compilation
I have two NXT bricks connected and they work together using Bluetooth, sending messages between the two works. The master NXT will start a program on the slave NXT with the RemoteStartProgram function. However, when I try to use RemoteStopProgram the compilation fails with 'Unknown function' in BricxCC and with this error when compiled with nbc:

```
File "/home/paul/bricks/carjulie_bt.nxc" ; line 124
#   __connectionWrite (1, __DCStopProgramPacket, __D0main)
#----------------------------------------------------------
1 errors during compilation

```

This is the relevant portion of the code, what am I missing ?

```
task main() {
  if (BTConnectToNXT("Sarah", SLAVE_CONN)) {
    RemoteStartProgram(SLAVE_CONN, "carsarah_bt.rxe");
    bool result = RemoteConnectionIdle(SLAVE_CONN);
    if (result) {
      Precedes(ListenToSarah,LookAtColours);
    }
    RemoteStopProgram(SLAVE_CONN);  // This line does not compile ?!
  }
}

```

Edit 2020-05-16: There is a simple workaround for this error, just send a message to all slaves to execute stopalltasks() function.

This bug is now also on Debian bugs: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960772

EDIT 2020-05-18: SOLVED! This link https://sourceforge.net/p/bricxcc/code/HEAD/tree/x64/ contains a working nbc version for Linux! Thanks!!

# Answer
Try changing which version of BricxCC you're using to one of the later releases: http://bricxcc.sourceforge.net/test\_releases/?C=M;O=D

What version are you using now? I duplicated the compile error on v3.3.8.9, but I didn't get the compile error on v3.3.8.11: http://bricxcc.sourceforge.net/test\_releases/test\_release20131007.zip

Hope that works!

PS: I didn't test anything, as I'm not using the feature -- I just saw it would compile on a different version.

If you use this, make sure you review compiler settings, as it looks like the newer version has **\[x\] Enhanced Firmware** option checked by default (which you may or may not have installed on your NXT brick, if using stock LEGO firmware).

## Update #1:

According to https://sourceforge.net/p/bricxcc/code/HEAD/tree/NXT/history.txt, it may be a known issue that was fixed in a newer release:

`Version 1.2.1.r5 (2013-02-16)
*:*
- Fixed definition for several Remote* API functions which sent direct/system commands
 to other NXT devices via Bluetooth or RS-485`

So, it looks like 1.2.1r5 or newer version of NBC command-line tools may be required.

Also, the test release I downloaded (v3.3.8.11 of GUI) has nbc.exe v1.2.1.5, while the other version I have (v3.3.8.9 of GUI) has nbc.exe v1.2.1.4 -- so this may be the issue.

## Update #2:

For Linux, see https://sourceforge.net/p/bricxcc/code/HEAD/tree/386/ and https://sourceforge.net/p/bricxcc/code/HEAD/tree/x64/ 32 and 64-bit binaries, respectively.
> 2 votes

---
Tags: mindstorms, nxt, nxc
---


# Question
Title: Can you identify this part? (Lego themselves couldn't)
These pieces (3 shown) predate 1990. I don't know which set they belong to or what they were/can be used for. I asked Lego but they didn't know either.

# Answer
> 14 votes
This is most likely Scala Jewelry Plate, Modified 2 x 2 (Human Bracelet segment).

Quite easy for me to find on Bricklink's search engine. All I did was type "plate 2x2 modified." Bricklink tells it appears in four sets which look like bracelet kits, but as of now it's too late to use them as bracelets because Lego has already invented newer ones. You might as well use these as a bridge or something.

---
Tags: part-identification
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# Question
Title: Can you identify the large transparent windows in this Ideas submission?
Can anyone identify the large curved transparent windows in this aviary build?

# Answer
> 4 votes
I believe this is Panel 6 x 6 x 9 Curved Top.

I couldn't find the other one that's containing the brown parrots, however.

Correct me if I'm wrong, because there were a few other parts like this which were almost identical.

# Answer
> 4 votes
The other transparent part is

Cylinder Quarter 4 x 4 x 6

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Tags: part-identification, ideas
---


# Question
Title: Are LEGO minifigs' arms supposed to come off?
I *can* get the arms off my LEGO minifigs, however, will doing so repeatedly wear them out?

# Answer
No, they are not meant to come off (and neither are their hands) and I imagine that doing so repeatedly will cause them to become loose, as is the case with hands.

I have noticed that the hands come off a lot easier nowadays compared to 1970s/1980s vintage Lego, but I'm rarely sadistic enough to rip their arms off :)
> 32 votes

# Answer
I did it regularly as a kid and, while it takes some effort, it had to be done a considerable amount of times for any damage to appear.

Removing arms allows for more variety in your minifigs, but also to use these elements separately for other purposes (never underestimate the usefullness of a single hand, or the architectural value of a torso).

Also, note that other arms have been produced (mechanical arm in the Agents theme, rock arms in Power Miners), so you can have interesting minifigs by using these. Same for boxing gloves recently released in the collectible minifigs serie.

One last thing - some minifigs are produced in China (for magnets, for example, or minifig collections) and there are some concerns about their quality, so you may want to be careful with these. Note that while the fact that they are produced in China (you can recognize them at the rectangle engraved in the arms) is a certainty, the fact that the quality is less good is subject for debate.
> 10 votes

# Answer
From my experience: Normally No! But you can yank them out softly. If you do it to often they'll become loose.
> 8 votes

# Answer
The only arms you can legally take off are found on Mos Eisley cantina aliens. Use the blue light saber to take them off cleanly.

By the same logic, you can only swap hands on certain Luke Skywalker minifigs. Or pirates. This is also true now for certain Anakin Skywalker minifigs.
> 6 votes

# Answer
In my case, it depends. On older minifigures from the 80's, 90's, and early 2000's it's okay. (I'm not saying it's a good thing) Sure, doing it too many times will gradually wear them down, but not enough to the point where the torso or arms break. New minifigures from 2012 and onwards though, NEVER TAKE THEIR ARMS OUT UNDER ANY CIRCUMSTANCES! Newer minifigures tend to crack and wear out more often. I don't know why this is, but it could be a decrease in the plastic's quality over the years. (LEGO seems to be running cheap) Taking out the arms can (and will) cause massive cracks down the side of the torso piece. Just recently I got new Luke Skywalker and tusken raider minifigures from set number 75173, and BOTH of the minifigure's torsos ended up with giant crack from the bottom of the torso upwards towards the arm holes within 1 week of each-other. This crack causes the arm to loose support and come loose. I was enraged by this, and had to re-order the torso pieces. In conclusion, I wouldn't take out a minifigure's arms unless they are from older sets.
> 3 votes

# Answer
Also, I have received several minifigures from various boxes that had no hands mounted to their arms from the factory, which indicate it is a "legal operation".

I don't think they aren't ment to be ripped off often, but if doing so gently, they shouldn't break.
> 1 votes

# Answer
They are not designed to be removed and doing so can make it hard to replace.

It is not a very good idea to remove Lego arms except on the minifigures listed above.
> 1 votes

# Answer
I've found that when a hand is pulled out it often (but not always) creates a crack in the arm, so that when the hand (or another different-colored one) is replaced it'll be a bit loose. It could certainly depend on the age of the minifig tho'.
> 1 votes

# Answer
I used to do it as a kid all the time and not always gently, what happens after a long time is: a small crack appears from the "armpit" down, it's less of a crack and more of a "line" and the arms become a bit loose but I'm not that bothered by it because it's nostalgic.

Lego minifigures are in perfect condition only when they stand on your shelf.
> 0 votes

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Tags: durability, minifigures
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# Question
Title: Unable to turn on NXT. Completely Frozen
I recently downloaded a file on my NXT and when I used it, it didn't work as intended. The motors started to make sounds like they were jammed, one got stuck and now the NXT won't even turn on. I tried pressing the reset button in the battery compartment but it doesn't help matters.

P.S. The thing I built was the NXT Mindcuber by David Gilday.

# Answer
The button in the battery compartment is NOT the reset button - it's a switch meant to be depressed by the NXT rechargeable battery. The NXT reset button is inside one of the technic connector holes on the underside of the brick - you can push it with an uncoiled paperclip or a pencil lead.

The reset button only toggles the power, it doesn't actually "reset" anything. The best way to reset the brick is to reinstall the firmware (this can be done from inside the Lego NXT-G programming software or from a 3rd-party utility like BricxCC). However, doing this requires that the brick has power and is able to turn on.

Try charging your batteries (if they're rechargeable) or put in new ones (if they're not). Your symptoms sound like the NXT was on the brink of the low-power threshold - putting load on the motors drained the batteries below a critical level and now the brick won't start.

Be sure to report back if fresh batteries don't work for you.
> 2 votes

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Tags: nxt, repair
---


# Question
Title: How can I make church bells with a pull cord?
I would like to allow the viewer to pull on some strings or chains and let that ring my church bells (I know it won't make much sound, that's fine). I'm thinking I'll need a pulley and some string, right? Then, do I just thread the axle through the pulley and attach the axle to the bell somehow? Are there any other parts I might need? Is there a good tutorial you can recommend for LEGO pulleys?

# Answer
It sounds like you're trying to implement a fairly simple bell mechanism such as this one:

You can certainly do this using some string and the pulley element that you mentioned.

I'd recommend tying the string to one of the holes in the pulley. Something like this worked reasonably well for me:

Here it is in action:

You'll likely want to do something to limit the range of motion so that the bell can't flip all the way around when the string is pulled too far. You should obviously make everything a lot prettier, too.
> 19 votes

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Tags: technic, design, castle
---


title: Night's watch torsos

text:
# Question
Title: Night's watch torsos
Are the torsos in this eBay listing made by LEGO? If so, can anyone identify them?

# Answer
From the EBay listing you posted:

> Precise Molded & Printed Items (MOC-My Own Creations)

Ergo, these are custom minifigs, not made by LEGO.
> 7 votes

---
Tags: minifigure-identification, castle
---


# Question
Title: Have minifig hands ever appeared "on their own" in an official set?
I am curious whether minifig hands have ever appeared "on their own", i.e., not inserted into minifig arms, in any official set. Or if they have ever been sold separately by TLG, e.g. in Pick-a-Brick or as a replacement part.

# Answer
> 13 votes
Proving a negative is hard, so disclaimer first:

## This answer is neither exhaustive, nor definitive.

My line of reasoning starts from the assumption that if there were ever standalone minifigure hands, they would appear in the set inventory in a way that is not explainable based on the number of minifigures. Of course, this assumption is not 100% waterproof, as it does not consider cases when a minifigure torso has appeared without hands AND a pair of standalone hand parts were also used, but I'd accept this risk.

Analyzing the list of the 16123 sets, books and gear catalogued in Bricklink that contain at least one minifigure hand, **there are no sets** where the number of included minifigure hand parts would be larger than the **expected amount**.

This number is the sum of all the following:

* twice the number of the included minifigures
* four times the number of four-handed minifigures (like Garmadon, General Kozu or Rio Durant)
* four times the number of monkeys
* twice the number of standalone minifigure torsoes (like the masthead of the Black Seas Barracuda)

Minus one for each pirate captain, Ogel, Baron von Barron or any other one-handed figure of course.

---

Some sets do appear to have more hands still, but that is because the number of hands is skewed by the inclusion of alternative figures, like in the case of Shoot 'N Save (FC Bayern Promo Edition), which allegedly contains 8 yellow hands, but only two minifigures (one of which is the goalie with black hands!), but the soccer player is included in four different variants. A similar thing is going on with Red Bus, where all possible flag-sticker combinations are listed to arrive at the 50 yellow hands for 5 yellow-handed minifigures.

If there are any omissions, I apologize in advance and congratulate the finder :)

# Answer
> 7 votes
I don't know of any sets with the standard minifig hand that isn't already attached to a minifig arm and torso, but if you stretch the definition of hand to include say, the robot arm in 8635-1: Mobile Command Center...

Then you could say that a minifig and one of their hands appears separately in the set and needs to be assembled.

Incidentally, that same hand is the ones found in a robot from the Exo-Force line (ie. 7711-1: Sentry), which could also be considered a minifigure.

Their hands (and all their parts really) come separately and need to be assembled. Couldn't tell you why the instructions neglect to show them in the assembly step though.

---
Tags: minifigures, inventory
---


title: Build a narrow archway

text:
# Question
Title: Build a narrow archway
Is there a way to make a more narrow v-shaped arch as in picture below? I looked at the arches section on Bricklink and they all look like they're too broad.

# Answer
> 4 votes
Couple of Brick, Arch 1 x 3 x 3 pieces produce somewhat similar archway.

---
Tags: design, castle
---


# Question
Title: How much energy do LEGO Technic gears lose to friction?
So, I recently watched a video by the Brick Experiment Channel about building a 1 Googol:1 reduction gearbox, which at the time of writing this question, is at #44 on Youtube Trending. At the end of the video, it makes the claim that the final gear will rotate once every 10^93 years. This seems unlikely to me; it seems much more likely that energy losses due to friction along the mass of gears will reduce the amount of energy it's receiving to 0, so it will never spin on it axis, at least as a result of this machine.

However, I'm left wondering where exactly this in the contraption energy is lost, and how much of it is lost to heat and how much is lost to noise. How efficient are LEGO Technic gears, when mounted on their standard X-shaped axles through the holes in standard LEGO Technic bricks?

# Answer
Nice find. First of all, it is interesting to see the various techniques they use.

The short answer to your question would be: It doesn't matter. Each gear, axle and all other components bend, stretch and absorb energy. This means that even for normal large LEGO Technic sets, such as the 42055, you have to build carefully and avoid too much pressure to reduce friction.

When it comes to Googol, it will take years to move most of the gears above their tolerance of, say, 0.1 mm. This is why they put the motor to the beginning of each section to show that it works in principle.

So, starting the whole thing will increase tension and some eruptive movements of the gears in the middle will follow. But the gears further down the line will never move.
> 3 votes

# Answer
The slower a gear moves the less power (energy per unit time) is lost.

So while each stage of the gearing does lose some power this is more than made up for by the gear ratio. There should still be plenty left to drive the final stage.

A bigger problem is whether the mechanism will actually survive for 1093 years of continuous turning or whether a combination of natural degradation of the plastic and wear from continuous turning will destroy it first. I would bet on the latter.
> 3 votes

---
Tags: technic, gears
---


# Question
Title: Can Power Functions components work with the RCX?
I don't have the RCX, and neither do I have any PF stuff, but as they both have wire connectors which are almost identical, I'm thinking that they can both work together and are compatible. Is this true? And can you connect more than one motor to one RCX port (RCX port has 4 studs but PF port has only 2)?

# Answer
RCX is compatible with the older 9-V system that came before Power Functions. However, since PF motors are also 9V and still unregulated as the RCX motors, a simple conversion cable suffices. The Power Functions extension wires will do (8886 or 8871) as they have on one end an underside that is compatible with the 9V/RCX system (which hence goes onto the RCX port) With this setup, stacking additional motors is possible as well, you can stack them on both sides of the extension wire (RCX side or side of 1st motor)
> 3 votes

# Answer
The RCX uses "electric system 9V" style connectors. These are not compatible with power functions connectors. The "electric system 9V" connectors have the connections built into regular lego studs (with the electric part of each stud carefully arranged to allow connections to be made between parts placed at right angles) while the power functions connectors have a special connector section that is not compatible with regular lego studs in any way.

As the other answer mentions the power functions extension cables (8886 for regular length, 8871 for extra-long) can be used as an adapter between "power functions" and "electric system 9V". This cable has two different connectors, one end is a regular power functions connector with "power functions" connections on the top and bottom. The other end is a special connector with "power functions" connections on the top but "electric system 9V" connections on the bottom.

There are a few caveats though.

* The power functions only end of the extension cable can be a bit of a pain to mount, because the electrical positions won't stack on top of regular lego studs.
* The RCX has a 1-plate high step next to the motor ports. This was not a problem for electric system 9V wires which had the wire exit near the top of the brick but the power functions connectors have a much larger cable exit lump. This means that the power functions adapter cable can't be placed on a RCX in the normal orientation. For the side motor ports you can exit sideways, but for the center motor port you either have to exit over the screen, use an "electric system 9V" cable between the RCX and the adapter cable (so now you have three sections of cable to deal with....) or use a 1x2 electric plate (part 4755) to build-up the connector on the RCX.
* "Power functions" is a 4-wire system while "electric system 9" is only two wire. So while you can use basic power functions motors with the adapter cable things like the servo motor will not work and you can't supply power to things like the IR receiver from an "electric system 9V source.
* For smaller models actually building your model may be a pain because of the extra wire length from the adapter and because the RCX was designed with old-style technic in mind while power functions was designed with new-style technic in mind.

As for connecting multiple motors you can do so physically but if the motors are under heavy load you may hit the current limits in the motor drivers, heck even a single "RC race buggy motor" can overload the drivers in the RCX.
> 4 votes

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Tags: power-functions, rcx
---


title: Where did "Cheese Slope" get its name?

text:
# Question
Title: Where did "Cheese Slope" get its name?
Why is this piece called a "cheese slope"? "Slope" I get; but "cheese"?

# Answer
A cheese slope resembles a chunk of cheese from a cheese wheel. They happen to also be the perfect size for minifigures to interact with:

<sup>‘Lego Cheese Farm’ by AIatariel, http://www.flickr.com/photos/alatariel1181/10582728886/</sup>
> 12 votes

# Answer
According to BrickLink, the cheese slope, part number 54200, first appeared in a handful of sets in 2004.

In the mid-1990s, the AFOL community hung out on the Usenet newsgroup rec.toys.lego and its predecessor, alt.toys.lego. A Google Groups search of the archives of these newsgroups finds no references to the cheese slope.

At some point in the late 1990s, the AFOLs gradually migrated to LUGNET, which had a member area, a forum, a set reference, a part reference, and other features. A search of the LUGNET forum finds a message from 13 June 2006 referring to "cheese wedge slopes." The message author seems to assume that readers are familiar with the term, so the cheese term was probably in common use before this message. Other LUGNET messages from ~2008 also refer to "cheese wedge slopes" rather than the current term "cheese slope."

In the early 2000s, the AFOLs started buying and selling, and later conversing, on Dan Jezek's BrickLink, which he called BrickBay for the first two years of its existence. The early BrickLink used to delete forum messages after 6 months, so the messages from the 2004-2006 period no longer exist.

Based on the part information on BrickLink and the message on LUGNET, it seems that the term "cheese slope" AKA "cheese wedge slope" came into being sometime between the introduction of the part in 2004 and mid-2006.
> 6 votes

# Answer
As was mentioned in another answer, the cheese slope looks like a slice of cheese at around minifigure scale. This part has also actually been used as cheese in official sets, including Medieval Market Village:
> 5 votes

---
Tags: piece-information, terminology
---


# Question
Title: How many unique Lego elements are there?
I’m looking for the number of “kinds” of pieces, not the aggregate number of all pieces produced. A breakout of Duplo, Technic and other “specialties” would be helpful as well.

# Answer
> 3 votes
Bricklink will be a source of the data to answer this question.

At the time of this answer Bricklink has 59610 items in its part catalog. However, this list contains such categories like "Sticker Sheet" (3422 items), "Stickers Over Assembly" (250 items), "Special assembly" (38 items) you wish to exclude, since they are not really individual parts. This leaves us with 55900 parts. It is worth mentioning this number includes "decorated elements", which are printed or stickered version of the parts. Most of these decorated elements exist in non-decorated form, however there are exceptions.

Out of these 55900 elements **DUPLO** has 4299 entries.

Now Technic is a bit more complicated. If we take just the elements in **Technic** categories there will be 2298 parts. Some Bionicle and Hero Factory elements could also be considered as Technic, however they are listed under their respective categories instead.

**Minifigure** categories account for 17758 elements.

Noticeable categories include **Bionicle** (595 elements), **Belville** (158), **Clickits** (372), **Modulex** (1172) and **Scala** (465).

Some other categories are small enough to contain all elements within single category like **Fabuland** (223 elements), **Galidor** (117), **Hero Factory** (253) and **Znap** (21).

---
Tags: piece-information
---


title: What are these pieces for?

text:
# Question
Title: What are these pieces for?
I got these pieces from set 76119 "Batmobile Pursuit of Joker", but the instructions don't specify what the pieces are for. What is their purpose?

# Answer
According to the official description, these are for customizing the completed build:

> This LEGO Batman toy playset includes 2 minifigures and children can customize their builds, minifigures and weapons with the included pack of 10 assorted Bat elements.
> 14 votes

---
Tags: part-identification, piece-information, sets, piece-usage
---


# Question
Title: Evolution of the LEGO part catalog over time
I have downloaded the Bricklink catalog four or five times in the past, but the interval was very irregular. I would like to look at the evolution of the LEGO part list over the years. However, I didn't find an option on Bricklink, or elsewhere on the Internet, to download past versions.

Are you aware of any archive of Bricklink catalogs? I haven't looked at other platforms with LEGO catalogs. Any other idea to get systematic information on the evolution of the part list is also welcome, of course.

# Answer
> 3 votes
You might be able to get the information that you are after from the Rebrickable database dumps. This includes set inventories for many sets, along with the year that the sets were released. Here's the full schema diagram:

A query something like this should provide a count of the number of sets every element has appeared in by year:

```

SELECT year,
       Sum(1),
       colors.name,
       parts.name,
       parts.part_num,
       colors.id
FROM   sets
       JOIN inventories
         ON inventories.set_num = sets.set_num
            AND inventories.version = 1
       LEFT JOIN inventory_parts
              ON inventory_parts.inventory_id = inventories.id
       JOIN parts
         ON parts.part_num = inventory_parts.part_num
       JOIN colors
         ON colors.id = inventory_parts.color_id
GROUP  BY year,
          colors.name,
          parts.name,
          parts.part_num,
          colors.id
ORDER  BY year DESC,
          colors.name ASC

```

Here's that dataset:

https://gist.github.com/jncraton/b0641ce5f8bc28e10e761a5ce1bafd51

Note that this query includes part variations (mold updates, prints, etc) as unique elements, so you may need to filter it down quite a bit for your use case. If you'd like to run your own queries directly against the full Rebrickable dataset, I maintain some scripts that make this fairly easy to do.

---
Tags: bricklink, part-database
---


# Question
Title: My LEGO character's helmet keeps falling off... Is there any way to fix?
My figure won't keep its helmet on and if I get it on it is very loose and will spin around.

# Answer
> 3 votes
The best and most effective technique I've come across is to use a bit of nail varnish on the inner anti-stud of the helmet piece, as Tonk explained on his blog TonksToysBlog. Just be sure to apply a very tiny amount and give it plenty of time to dry.

Also, if it matters to you, the helmet you have pictured *does not* go to the figure pictured. The figure is Jay Legacy from 2019. The helmet, on the other hand, is 98133pb02 from 2012-2016.

# Answer
> 1 votes
Hmm... Looks like his character is fairly new, with it being introduced this year, *Jay (Legacy)*. With the relative newness of the pieces, I'm surprised the clutch strength is at issue.

Well, anyway, head over to *LEGO*'s customer service page and fill out the request to replace your broken piece(S). I'm emphasizing because we don't know which piece, Helmet or Head, is "jayed" up.

*Part #40925pb02*: Minifigure, Headgear Ninjago Wrap Type 4 with Dark Blue Headband Pattern.

*Part #3626cpb1892*: Minifigure, Head Dual Sided Reddish Brown Eyebrows and Freckles, Lopsided Grin / Frown Pattern (Jay) - Hollow Stud.

Request to replace broken pieces *HERE*.

---

Parting words of advise: "Sunlight is the *LEGO* killer": Be cautious of any of your precious pieces being exposed to direct sunlight. The darker the piece the more warping sun heat it will absorb. I've ruined sculptures this way, where they just fall apart after spending a month in the sun on a shelf.

# Answer
> 1 votes
I've had the same problem with two of my new LEGO sets. However, I've managed to fix my Stormtrooper helmet by taking a small piece of a rubber band about 2 centimeters long and put it between the helmet and the head. The rubber slows the spinning and it doesn't fall off as easily.

# Answer
> -1 votes
Assuming that they came together as a set, some Lego helmets don't fit tight in order to make it "easier" to put the helmet on, and if not, might not fit correctly at all. However, there could be an issue with the pieces itself. Get a cotton swab and some water, DO NOT USE ALCOHOL, as it will eat at the paint, and clean out the contacts.

---
Tags: minifigures, repair, ninjago
---


title: Help with popcorn cart wheels

text:
# Question
Title: Help with popcorn cart wheels
Can someone identify the wheel attachments for a LEGO popcorn cart wheel like this?

How do we connect it to the axle? Is there a good tutorial on LEGO wheels somewhere I can read?

# Answer
The "wheels" are really the hubs, mostly from the various Speed Champions cars among others.

The inside of the wheel takes a standard stud, so you should be able to use:

1. Plate Modified 2x2 with Pin Hole
2. Technic Pin 1/2
3. Wheel Cover 5 Spoke

Beyond the primary question of how to build these particular wheels, there are a few common themes among wheels and axles across the system (there are clearly more than those shown here, but these cover most of the typical "official" connections you'll come across at the moment):
> 9 votes

---
Tags: design, vehicle
---


title: How do the Ninjago spinners work?

text:
# Question
Title: How do the Ninjago spinners work?
How do the Ninjago spinners work? From the set it looks like you can put a minifigure on it. It's a little hard to understand how that works from the picture though.

# Answer
> 5 votes
I've had a few of these in the past, and I've managed to find one so hopefully I can explain it with a few pictures.

They are simple, hand-powered spinning tops, best spun by a finger and thumb:

Usually the original spinner would have a Plate, Round 2 x 2 with Rounded Bottom on the bottom to aid spin:

Although clearly these became more advanced as per the other examples with pin holes in the bottom for further attachments.

The minifig stands inside the spinner, only lightly held on by the parts inside:

The interesting part is the light grey part that holds the minifig's feet which can go up and down, which happens when the dark grey part is rotated:
**Lowered:**
**Raised:**

And it was this action that made the game you'd play with them: By getting two people with spinners, you could spin them at each other, and hope that they'd bump, or at least the characters with their weapons would catch on each other, and this would cause them to rotate within the spinner, lifting them up, and hopefully knocking one off!

The cards would then allow you to add additional weapons to your minifig, or parts to the spinner itself, either raising it up, or building up "defences" that would stop the minifig from rotating, and so keep it in place for the next battle.

# Answer
> 1 votes
I've found a manual online for set 9591 which includes one of these spinners, but it has no English instructions. I decoded all of the translations using Google translate, but they only told what you should do depending on which card is available.

Then this part of the PDF rang a bell in my head:

As you can see in the image, the hyperlink in your question leads to only one of the parts required to build the spinner, which is this one. Also, you **can** attach minifigures to it as shown. Based on the looks of that grey bottom part, it's pretty much a typical top. This part of the image also contributed to that conclusion:

So it seems like these are ordinary tops like I already said. They don't seem to have any special mechanism like Beyblades or any other special tops, but they **did** make similar tops before these came out.

---
Tags: ninjago
---


title: Red Palisade Brick?

text:
# Question
Title: Red Palisade Brick?
Is there a red variant to the 2x1 palisade brick (30136)? I looked at bricklink but couldn't find anything. Known colors don't include red or any similar shades, but I feel as if I've seen the red bricks before.

# Answer
As of this moment, officially - no. The ones available for sale are, most likely, test runs that made their way from LEGO factory since none of them have been included in any of sets. Red is known to be common color for running tests with injection moulding. Quite a few other test parts in Red (the color that hasn't been used by those particular parts in any of released sets) have made their way from factory and have been offered for sale.
> 7 votes

---
Tags: colour, bricklink, bricks-and-pieces
---


title: Can you identify this torso assembly

text:
# Question
Title: Can you identify this torso assembly
Can anyone identify this torso and arms? I did a search on Bricklink for torsos with 'fur' and 'belt' but couldn't find it.

# Answer
> 1 votes
I found another listing for the same minifigure on Etsy with extended description, which doesn't mention LEGO parts have been used. Otherwise that would be a selling benefit. Also, two sentences below, extracted from description, make you assume minifigure is built from non-LEGO parts.

> This custom Minifigure works with any building block set.
>
> These figures are custom figures and are only compatible with LEGO® but are not in any was associated or endorsed by them.

Now if you are still in doubt, we could check if Bricklink has them. Torso and legs seems to be in Light Bluish Gray color. While such legs exist as LEGO item, checking torsos, assembled torsos, body parts (arms) in this color it can be be concluded that torso and arms have non-LEGO print. These still could be made of genuine LEGO parts, but print is custom.

Hair looks to be in Dark Orange, which exist both in LEGO form as Minifigure, Hair Female Mid-Length with Braid around Sides and a color.

# Answer
> 0 votes
The seller says that it was handmade, and Lego minifigures are not made like that. And it **clearly** says this in the product description:

> Game of Thrones Ygritte custom mini figure.

This most likely means that this is a **MOC** figure. Like I said before, Lego would not bother to buy the *Game Of Thrones* license (it is already purchased by Mega Construx anyways) and they don't even spell the word "minifigure" as "mini figure." As told in the comments, the head, hair, and grey pants are not in Bricklink's database, so I'm still sticking with the fact that it's a MOC figure. I typed "head blue eyes" "orange hair" "pants grey" but none of them appear. This therefore offers more proof to my answer.

---
Tags: minifigure-identification
---


title: In what set is this brick used?

text:
# Question
Title: In what set is this brick used?
In which set is this LEGO brick used? There is no number in it and it's original LEGO. The only number on it is "A 1".

# Answer
The specific part (870) is identified in the other answer, however it is part of an assembly with its own part number:

https://www.bricklink.com/v2/catalog/catalogitem.page?P=827#T=C&C=3

827 Vehicle, Tractor Chassis

870's page mentions it has extra parts that it is used with, and 827 is the complete assembly (steering wheel + mechanism).

This page details what other parts are needed to complete it.

https://www.bricklink.com/catalogItemInv.asp?P=827

870 is the base in the picture, and 871-874 are the mechanism pieces.
> 14 votes

# Answer
That's Vehicle, Tractor Chassis Base 11 x 2 x 3

Following the link to bricklink, you can see that it was in four sets in the 1970's.
> 12 votes

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


title: Winch with String

text:
# Question
Title: Winch with String
I'm considering buying a few winch's with string. I don't understand what I need to make it turn. It doesn't look like a regular technix axle goes inside it right? I've looked at a few of the instructions for sets it's supposed to be in and I can't find where it's used. What parts do I need to purchase with it?

# Answer
> 4 votes
It actually *does* take a Technic axle and has been used with such in some sets, although in most old sets I know it was usually supposed to be operated manually by rolling the drum with your fingers.

If you look at the picture of the individual drum piece, you can just about see the axle holder inside, even though the round hole itself is bigger. So you can stick a normal Technic axle into it and do whatever you want with it, but this really depends on the actual build you're trying to accomplish and nothing precludes you from simply making it hand-operated either.

From 2019 set 60216:

---
Tags: technic, piece-usage
---


title: Decorations on drawbridge

text:
# Question
Title: Decorations on drawbridge
At about 0:28 of this video, it depicts a descending drawbridge with some metal decorations. Are there any decorated tiles that come close to this? Is there some other way I could achieve a similar looking effect?

# Answer
This part is a typical wood plank with nails (which are metal) on it. There are many variations of it, and almost all of them have nails, therefore they don't really count. However I've looked at all variations and the only ones I can find that have more metal are this one, this one and this one.
> 1 votes

---
Tags: design, castle
---


# Question
Title: What is this small space-themed set from possibly the early 90's?
I have a bunch of LEGO bricks mixed together. I recognize a few of them as going together for some small set that I no longer have the instructions for. I believe I got this set in the early 90's. The minifigure rode some sort of small contraption. What set is this?

# Answer
This is most probably Ice Planet Scooter:
> 28 votes

# Answer
Ice Planet - Looks like Star Wars before Legos marketed for Star Wars. https://lego.brickinstructions.com/en/lego\_instructions/set/1711/Ice\_Planet\_Scooter
> 5 votes

---
Tags: set-identification
---


title: Identify red triangle stick

text:
# Question
Title: Identify red triangle stick
Help me to identify this part please.

# Answer
That's Train Direction Switch - 4.5V 2 x 3
> 8 votes

---
Tags: part-identification
---


title: Can you identify this dome

text:
# Question
Title: Can you identify this dome
Can anyone identify this dome? I looked through the "brick,round" section of bricklink and couldn't find it.

# Answer
> 3 votes
That's Cylinder Hemisphere 4 x 4.

---
Tags: part-identification
---


title: What is this brick and how do I use it?

text:
# Question
Title: What is this brick and how do I use it?
My son received a huge assortment of legos for his birthday and one piece we would like to know how to use, but I can't seem to find information on it anywhere! I would sure appreciate any help you fine folks might be able to offer. I am not able to share my picture because it's too big. The part I'm talking about is this one. The only words or numbers I can find on ours is "2002 lego group" and the numbers "2223". Thanks in advance. :)

# Answer
This is

* Record and Play Module, 16 x 10 x 4 with Built-in Motors 4.5V (Item No: 3173c01)
> 1 votes

---
Tags: part-identification
---


title: Bionicle generation 3

text:
# Question
Title: Bionicle generation 3
Hey LEGO will you make another Bionicle reboot? If you are is it going to be a bit more like g1 but also bring back a few g2 characters and I hope it is either ccbs, you bring it back or technic like the original, and not system.

# Answer
> 1 votes
While only LEGO themselves can answer this question, there is a proposal for a 20 years of bionicle set on LEGO ideas that had achieved 10,000 votes and is currently under review. Depending on the outcome of the review process, it may become an officail LEGO set in a few month.

---
Tags: technic, bionicle
---


title: LDD part library missing

text:
# Question
Title: LDD part library missing
I have deleted the LDD part database (part library) by mistake. As many of you know, LDD can no longer run in online mode, which means it can't update itself.

Is there any possibility to download the parts from somewhere or recover them somehow?

# Answer
Here's an archive of the LDD part library for you to download, but I am not certain if it works. Give it a try.

Alternatively, if that link ever breaks down and you have Windows 10 you can right-click on your recycle bin, press open, then right-click on the library file pending deletion and press restore. It will come back.

P.S. If you doubt you will ever use this feature again, you can disable it by right-clicking recycle bin, clicking "properties", and selecting "Don't move files to the Recycle Bin. Remove files immediately when deleted".
> 2 votes

---
Tags: ldd
---


title: What is inside BuWizz 2.0?

text:
# Question
Title: What is inside BuWizz 2.0?
I'm interested in Buwizz PCB and components. Can someone share good photos of the Buwizz PCB (both sides)? It will be very cool to see Buwizz 2.0 but older versions will also be good.

# Answer
> 7 votes
I don't have this part, so I can't directly give you the photos that you are looking for, but there is at least one teardown video floating around that we can use to see what is inside the BuWizz 2.0 module.

## Power

The module contains 2x 850mAh LiPo batteries:

## PCB

The top of the PCB looks something like this:

I wasn't able to find an image showing the back of the PCB

## Components

### System on a chip

From the above images, we can see that the main microprocessor is a Cypress PSoC 4200 series. Looking at the datasheet, we see that is a BLE-enabled system on a chip running at 48MHz with 128KiB of flash.

### Motor driver

There are at least 4 DRV8833 chips present on the PCB. This chip is a dual H-bridge. The datasheet for the part indicates that each channel can handle 1.5A RMS/DC or 2A peak. The specs for the BuWizz indicate:

> Performance
>
> * Max continuous current per channel: 4 A
> * Max instantaneous current per channel: 6.5 A
> * Max continuous power per channel: 36 W (HIGH speed mode)
> * Max instantaneous power per channel: 55 W (HIGH speed mode)
> * Max total power: 45 W
>
> Speed Modes
>
> * SLOW: 5.2 V
> * NORMAL: 7.2 V
> * FAST: 9.2 V
> * LUDICROUS: 11.2 V

I'm not sure how 4A per channel is achieved safely using the DRV8833. Given that 4 dual H-bridges are included, it is safe to assume that each chip is driving each output using both H-bridges in parallel, but according the the datasheet, this still only gets us to 3A RMS/DC per channel.

My hunch is that they are simply driving these parts harder than intended. We can see that they are using them at 11.2 volts, while the datasheet recommends a max operating voltage of 10.8 volts. It's worth noting that the max quoted continuous power per channel (36W) is very close to what you would get from a parallel configuration running at 11.2V (11.2V * 3A = 33.6W).

The BuWizz has carved out a niche for itself by going well beyond recommend operating power (the LEGO PF battery box tops out at 9V * .8A = 7.2W or less than a quarter of the BuWizz), so I wouldn't be surprised if they are running the motor drivers a bit hot.

---
Tags: clone-brands, electronics
---


# Question
Title: Lego filling boxes with random lego to meet law requirements
In some countries, there is a law that toy boxes need to filled with at least a fixed percentage of the total volume of the box. I know Lego addresses this by adding random Lego. At least, I've been assured this during a Lego seminar by a Lego employee (probably community manager) at one of the fanweekend events (Paredes de Coura or Skaerbaek).

However, does anyone have a reference for this, perhaps pictures of what random Lego is added?

# Answer
Not sure if this is a partial answer, but an example is quoted in the act to repeal parts of the Californian (USA) slack-fill legislation:

*Toys. Lego has been sued for slack fill on its "Aqua Zone" building sets. The boxes which contain the sets are uniform in size, and contain from 29 to 33 pieces, depending on the set. Each box contains an "actual size" representation of the pieces and a clear and conspicuous disclosure as to the number of pieces.*

From: SENATE COMMITTEE ON BUSINESS AND PROFESSIONS BILL NO: AB 1394 AUTHOR: Figueroa and Senator Richard G. Polanco, Chairman Escutia As Amended: 9/4/97 HEARING DATE: September 5, 1997 FISCAL: Yes SUBJECT: Packaging and Labeling: expansion of exemptions to slack fill laws.
> 3 votes

---
Tags: sets, lego-group
---


# Question
Title: How were these building instructions from the 1970s produced?
Have a look at page 7 of the instructions for set 367, produced in the year 1975 (source: Peeron.com):

How were these instructions produced? Were they hand-drawn or computer-generated? If the latter, which computer system and software were used?

# Answer
> 12 votes
They would have been hand drawn.

Technical illustration used to be a highly skilled job, similar but slightly different to design draughtsmanship. I can still recall the latter being used about 20 years ago in engineering. There were tricks to remove some of the repetition (drawings were done on translucent drafting film and could be duplicated optically, and templates and stencils were widely used). Translucent film also means it was possible to work on an isometric grid behind the drawing.

*2D* CAD software, while it dates back to the 1950s, only became accessible, though still very expensive, around the time these 3D drawings were produced. 3D CAD/modelling with rendering is a 1990s invention, and now any fool can use it (e.g. me), and it can be made cheap and user-friendly enough to give away (e.g. Lego Digital Designer). Rendering using something like POV-ray (which can still be used with LDraw) could take days for a single image on a fast PC in the 90s (though you wouldn't need to render like that for these illustrations).

Also, while it's hard to tell with the JPG artefacts and anti-aliasing, if you look closely at say the wheels in panel 8, they're not quite a perfect match; they would be if rendered from the same model.

Here's a picture of what's available at the click of a mouse these days (2020):

I used this 3rd party model of a 2x4 brick and a range of view options in Autodesk Inventor (3D modelling software). The top right clearly imitates the old manuals, and the style is called "Technical Illustration". Lego tend to use fairly heavy shading on studs, demonstrating that clarity and style are closely related. Newer instructions use thinner black edges (with better quality printing). The bottom right is suitable for box art but doesn't clearly show the joins between bricks - at a glance the bottom could be a 2x8. This took less than a minute to render on 1 core of my desktop; 20 years ago it would have taken hours.

# Answer
> 7 votes
I doubt in the mid 1970's that The LEGO Group had any computer aided design tools. I was in university during that time and this kind of documentation was all hand drawn illustration.

Remember that computers at that time were big, power hungry and really, really expensive. For what it would cost just to purchase, install and operate one computer for a year you could hire four comercial illustrators for that same year.

---
Tags: instructions, history
---


# Question
Title: Simple way to build large circular plates?
I was wondering if there is a simple way to create a large circle or circular plates. I want to build a MOC of the Hero Factory assembly tower (*In LDD first*) but most of the pieces that form circles don't give enough clearance for a decently sized CCBS model. I was wondering if there were any bricks or techniques that would help for this specific MOC.

# Answer
The largest truely round base plates in the LEGO system fit in a 8x8 square. You can build them from two LegoPlate, Round Half 4 x 8 or from four quarters.

For a bigger (and thicker!) base plate there is a Duplo version of the above mentioned base plate, fitting into a 16x16 studs LEGO system square: LegoDuplo, Plate Round Corner 4 x 8 Double

EDIT: For a thicker base, you can use these bricks: Brick, Round Corner 10 x 10 with Slope 33 Edge. They make a base fitting into a 20x20 square.
> 3 votes

---
Tags: building, moc, hero-factory, system
---


title: Anybody know what this piece is called?

text:
# Question
Title: Anybody know what this piece is called?
This came from a little car, and I'm trying to build that car using LDD, but I can't find the piece. Can someone help?

# Answer
> 16 votes
On Bricklink this is called Wedge 3 x 4 x 2/3 Cutout.

As Uli pointed out in the comments this part is called "**FRONT 4X3X2/3 W. BOW**" in LDD. The given image looks very similar. You can also see if this is really the part you're looking for by looking at the 3D model of it.

---

<sub>**How I found it**: Searching by properties did not work (which usually does), and I knew that many Lego city police sets had red-colored vehicles, so on google I searched "lego city police" and hit images, and I saw an image of the front of the box for set 60243 which showed a truck that seemingly looked like it had this piece and I found the same set on bricklink. Then I looked at the part list, and it had this part!</sub>

---
Tags: part-identification
---


# Question
Title: Lego Pneumatic Engine: Possible Damage from Baking Soda and Vinegar?
I have a question on Chemistry.SE about secondary reactions producing something other than CO2, and from a bit of discussion there, the answer seems to be that there aren't any, but some of the original ingredients can get splashed up into the LPE.

**So, has anyone tried doing that? If so:**

* **What was your setup?**
* **How did you clean the LPE afterwards, if at all?**
* **Was there any damage after a few days?**

---

I'm thinking about a 3-step process, but I'm also wondering if it's even necessary:

1. Run it on Baking Soda and Vinegar as planned.
2. Run it on Water to rinse out whatever raw ingredients might have gotten into it.
3. Run it on Air to dry out the water.

The water is probably from a garden hose, with the unsolved problem of how to hook it up to a Lego hose.

The air is probably from a shop compressor with the regulator turned down. I have a bicycle pump for testing, and a sports inflator needle to make the connection, but I don't think I want to pump it *that* much!

---

The reason to use Baking Soda and Vinegar at all, instead of just using Air in the first place, is to have a compact, self-contained system that can run itself around a track for a while, and be able to start and stop on command without over-pressurizing for lack of use or running out from constant use.

So, I've rigged up a pressure-regulated, motorized air pump to displace vinegar out of one small plastic water bottle, and into another that has the baking soda, which then creates the working gas.

I've seen a big bank of pre-pressurized soda bottles on an LPE-powered car, but that's just too bulky for what I'm doing.

---

Some pictures may help:

The water bottle sits horizontally, under the black "hold-down bridge", with the bottom against the RCX.

"Steam" locomotive with Walschaerts valve gear. And yes, it runs. :-) Both directions.

(Wires and sensors are in false color to show the connections.)

There's also a tender car with the other water bottle and the air pump to displace something out of it.

# Answer
> 3 votes
I see two main problems that need to be adressed here.

1. Intrusion of liquids into the pneumatic system
2. Intrusion of solid particles into the pneumatic system

To filter out solid particles, namely baking soda, a fine mesh could be used, either alone or in multiple layers.

To get rid of droplets, some absorbing material such as cotton could be inserted before, after or rather between the layers of mesh.

So if we can suppose that the bottle will have an exit point that is always clear from the liquid-solid phase (based on your comment "with hose connections in the cap"), we can imagine the following filter system built inside a small diameter tube (like a plastic straw), where # denotes layers of fine mesh fixed inside the pipe, capable of holding back both baking soda dust and the loose cotton swabs:

```
 ________________________________________
/                                        \
|                                         \
|                                          \
|                                           \___
|                                               |
|            #cotton#cotton#cotton#cotton#======+
|                                            ___|
|------------------------------------------ /
|    o     8      O   Ö    *     0    .    /
|  °    vinegar + baking soda   :    ö    /
\________________________________________/

```

Or if you need to fill the bottle more than halfway, but can ensure that the sloshing will not reach the top of the laying bottle, then you might be able to use a doubly-bent straw:

```
 ________________________________________
/                                        \
|        #cotton#cotton#cotton#cotton#=\  \
|                                      \\  \
|                                       \\  \___
|----------------------------------------\\-----|
|  :         *           ö                \=====+
|       o      Ö    0        8     O    .    ___|
|   °                 Ö                     /
|    o     8      O        *     0    .    /
|  °    vinegar + baking soda   :    ö    /
\________________________________________/

```

But as MaxW has noted on your question over at Chemistry.SE:

> You won't get pure CO2 out of an aqueous solution. There will be water vapor in the CO2.

So your metal parts will definitely be exposed to a (probably highly diluted) carbonic acid, that "can corrode, rust or pit steel but the extent of those effects depends upon the chemical composition of the steel. Stainless steel, in contrast, resists general corrosion caused by carbonic acid." (Source)

How fast of how much will the parts be corroded? I can't find a definitive answer for that, but in the end, it all comes down to three, highly variable factors:

1. The exact composition of the steel used in your pistons (pretty much unknowable, especially since the particular pistons are about 20 years old)
2. The concentration of carbonic acid in the generated stream of CO2 (depends on the filter, the water content of the vinegar used and probably other factors as well)
3. The duration of exposure (that can be minimized by applying the cleaning steps outlined in your question, but consider that rinsing with water brings another set of problems, like limescale or rusting - so if I were you, I'd skip step 2 and only run it on warm, dry air to remove any moisture from the system)

Looking forward to read your experience!

---
Tags: pneumatic
---


# Question
Title: Pirates of Barracuda Bay 21322 - Is there a way to get the ship pirating-worthy?
From what I have read, when you convert the island to a seaworthy ship, you are still left with the inn part, and no cannons on the ship. All the portholes are gone or converted to windows.

Is there a way to get the cannons back on the ship? Preferably using only pieces from the set? If pieces needs to be added, what is the simplest way to make that conversion?

# Answer
> 13 votes
The review over at Brickset mentions this exact modification:

> Pearl gold windows are fixed inside each gunport, preventing the deployment of cannons. While this seems slightly odd, **the lattices can be removed** and replaced with cannons, as demonstrated here. I appreciate these options but **some furniture must be removed from inside to create enough space for the weapons**, corresponding with the officers' quarters on historic ships where cannons could replace tables and chairs during battle.

(Emphasis by me)

---
Tags: building, sets, set-modification, ideas
---


title: Downloading EV3 programs: Error code 0

text:
# Question
Title: Downloading EV3 programs: Error code 0
When I download some programs to my EV3, the application gives me an error as shown below.

Error downloading Projects/SUP3RCAR/ResetSteer.rbf during deployment. Error code:0

Can somebody tell me why this error occurs and how to solve it?

# Answer
Yeah... It happened to me this very day...

SOLUTION:

One of the following always does it (listed in descending order of effectiveness):

1. Relaunch the EV3 Software (Be sure to save your work!)
2. Use a Download Cable instead of Bluetooth
3. The EV3 Software messes up on Windows 10; try using an older PC.
4. Restart the brick.
5. Restart the computer.
6. Try turning bluetooth on and off
> 1 votes

# Answer
Try recharging the robot. Sometimes, the robot acts up when it is not full battery.
> 0 votes

# Answer
I reset my program in the memory because i have a lot experiments in the memory, with the memory explorer
> 0 votes

# Answer
I reinstalled EV3 software on my PC (Windows 10) and it solved the problem for me.

First I installed Silverlight and next EV3 software. Then I uninstalled everything and I installed only EV3 software. Silverlight was installed in the background and the problem was solved.

I found this concept on http://www.legoengineering.com/ev3-gone-wrong
> 0 votes

---
Tags: ev3, ev3-g
---


# Question
Title: Are all of these police minifigs from LEGO?
While I'm glad LEGO is taking a principled stand on recent events, I've seen this set of police minifigs circulating on social media portraying the evolution of LEGO Police through time:

I don't have any trouble believing the 3 minifigs on the left are legitimate minifigs from LEGO sets, but the fourth one looks much more militaristic than I imagine LEGO would put into a set. Can anyone identify this minifig or confidently rule out it being a LEGO minifig? If anybody wants to identify the first three, that would be cool too.

My first guess was that the long gun was from BrickArms, but I didn't see anything there that has a scope and a forward handgrip. Can you identify the assault rifle?

# Answer
As pointed out by others, the first three minifigures are genuine LEGO (with the second having perhaps a few custom accessories). The fourth is not a LEGO minifig. It may include some genuine LEGO elements (legs, hands, etc), but the militaristic accessories are not LEGO elements. This appears to be a custom minifig sold at one time by Modern Brick Warfare.

Not only does LEGO not include guns in their City sets, they also have much better lighting for their minifig photos than this.
> 35 votes

# Answer
These are identified from left to right.

Series 18 of Lego Minifigures has that first policeman. Here is the exact minifigure.

The second one appears to be from Series 9 of Lego Minifigures. Here is the exact minifigure.

The third policeman appears to be LEGO Policeman with Riot Helmet Minifigure with a different head. The head might be Minifigure, Head Male Black Eyebrows, Chin Dimple and Lopsided Grin Pattern - Hollow Stud.

As Alexander O'Mara pointed out, the fourth one is *totally* not official Lego. It is likely this guy and whoever made the timeline did not bother to think about the excessive military detail in this minifigure (Lego doesn't even make military content anyways).

---

Actually, the "timeline" is quite inaccurate. The first policeman being shown was actually released in 2018, however it is most likely a reference to the very first policemen (which look almost identical). Sometimes I mix up the two minifigs by accident, and I suppose the same story goes here (or (s)he probably did it because there are not many good pics of the early police guys y'know). The second and third policemen being shown were released in the same year, 2013. And the fourth one is not even real Lego, so who even knows about when it was made??
> 13 votes

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


# Question
Title: Why does LEGO avoid 2x4 plates on these occasions?
As this year's LEGO city advent calendar gradually gets opened, I have repeatedly been astonished by the choice of parts: At least twice so far (in the oven and in the catapult target), two 2x2 plates of the same colour had to be placed right next to each other.

Why in the world would LEGO design a (mini-)set this way, rather than use a single 2x4 plate? Note that I have seen LEGO prefer two 1x2 plates instead of a single 2x2 plate in a recent build, but those were placed right on top of another 2x2 brick. Thus, presumably, differently sized plates were chosen for the ease of later disassembly. However, in the case described here, that's not the case, and arguably, the resulting mini-models end up a little bit fragile like this.

I wondered whether it's just some less usual colours that this happens for, but in the catapult target, the colour of the 2x2 plates is white. Certainly, LEGO has not stopped producing white 2x4 plates?!

**What's the reason for this strange part choice? Is LEGO trying to achieve a certain part count across the calendar?**

# Answer
> 6 votes
While it's unlikely that we would get a somewhat official answer on this, there can be a multitude of reasons for that, some logical, some economical, some motivated by marketing. Of course, there are some more obvious reasons for the sake of the build and the art of LEGO, but they might not apply in the case of a calendar:

* **Design.** This isn't necessarily the case for using 2x2s over a 2x4 in a calendar. But for example think of something as the Architecture Robie House, where they used 1x2 and 1x1 plates, about 1000 in sum, to simulate the actual brickwork of the real house when they could as well have built it from much fewer bricks. While this also significantly increased the part count, I would still argue this was primarily done for its aesthetic value and it works.
* **Reusability.** Again not too relevant in the case of a calendar, but a lot more important for something like a Creator 3-in-1, when building something else from the pieces is not only encouraged but intended and part of the product's appeal (you could say it's implicitly part of the appeal of LEGO bricks in general, but that's not necessarily reflected in the actual marketing and business philosophy anymore).

A more economic look at the situation opens a few more possibilities that might apply more specifically to your case. While LEGO certainly has more freedom by basically holding all the cards, I found it sometimes **helps to think about your own MOCs and why you'd choose one part over the other**. When designing a model the first intuition is to use the most fitting part, but there are various considerations to switch them out, almost all of them economically motivated:

* **Available colours.** This is certainly the strictest consideration since you can't use a part that's just not available. While LEGO *would* have the freedom to simply create the part in that colour, there are still considerations of bringing yet *another* unique colour-shape combination into production, especially if you don't need it in too many other sets, above all something as much of an afterthought as a calendar. Though, this might not apply so much to something as simple as a 2x4 plate, there's still a ton of exotic colours that don't even have that, even if white is anything but exotic.
* **Item price.** Now for MOC designers, this is motivated a bit differently, since the price of a piece isn't driven "naturally" by actual material cost rather than "artificially" by the demand and supply created from its availability in official sets. That's why 2 2x2s can be much cheaper than a 2x4. But even for LEGO, who basically could mold as many parts as they want, this isn't really driven by material. The material really costs about *zero*, no matter if you print 2 2x2s or 1 2x4. It is the factory configuration, the logistics of bringing pieces to together, the use of the piece in other produced sets. These all figure into the production cost.
* **Lot count.** In fact when designing a MOC, especially if I intend to build it myself, another consideration is keeping the lot count down. If you already need 2x2s anyway and you don't need a 2x4 for structural integrity, then it might improve your model's acquirability if you have to shop for 1 lot less, since someone offering 5 2x2s is likely offering 7, too. I'd think this isn't too much different for LEGO if you consider the above points about the logistics of molding parts and then packaging them into a single set. Better mold two more than bringing another machine configuration, production lane or, god beware, factory into the mix. And in fact, I often observed that in official sets, where I wonder why they'd use two parts instead of a more fitting one only to see that there's already 20 more of those two parts in the set and it starts to make sense.

All these factors are driven by purely economical reasons and based on the assumption that **production and logistics make much more of the cost of a piece than just its material**, especially when amortized over tons of pieces and when the difference in material between 2 2x2s and 1 2x4 isn't that big to begin with. But of course there could be another, still economical but less directly, reason based on marketing:

* **Part count.** As noted in the question, this might very well be to just amp the part count of a set, or a calendar where the individual part count of the models isn't too high anyway and you can basically increase it to quite some degree with just adding a few more pieces. A higher part count makes the set *seem* more valuable (since it suggests more material and a more complex design). This can be the truth but doesn't have to, depending on what factors you measure value by and how it's practically implemented.

Though, I would agree that **structural integrity *should* prevail** over all these reasons since a model that just doesn't stay together is of no use at all. But it can still be relative how fragile is *too* fragile and you also have to figure into the matter, that the advent calendar is somewhat of a side thought that **might not be driven by the highest of quality and design considerations** from LEGO, especially regarding the buildable items when many people seem most interested in the figures.

---
Tags: design, advent-calendar
---


title: Brick-built sails for a pirate ship

text:
# Question
Title: Brick-built sails for a pirate ship
I am building a Sea-Cow(70810)-like ship that of course needs sails. The sails should be larger than the Technic fairings used in the LEGO movie set, but I want to avoid cloth sails and strings.

My idea is to connect rows of white 4x6 modified tiles with studs on edges (part 6180) with hinge plates. That would give a curved rectangular sail. However, sails usually are not rectangular.

Do you have experience with sails made out of tiles or plates? How do you create the shape/curvature you have in mind? I appreciate any ideas.

**EDIT:**

After very useful suggestions by @jncraton I was able to create a prototype of sail. I found some hinges (4275/4276) to connect the rows of tiles. The brown plates are not the final solution. Now I still have to figure out how to make the sail less rectangular.

# Answer
> 10 votes
Great question. It sounds like you are building a fairly large ship. If the scale is large enough, brick-built sails can look quite nice. You can add shape, contour, and texture using various building techniques.

If you want to keep things simple, you could just use a single layer of bricks as was done in this basic sailboat model that was an in-store build back in 2009:

That example obviously isn't the most detailed. It's challenging to develop sail-like contours with studs on top.

Here's one example just using plates that is similar to what you mentioned in your question:

Notice how it uses wedge plates to round off the square corners of the sails. Wedge plates come in a variety of shapes and sizes, so that gives you some flexibility in the shape of your sail. Here's another shot showing that technique more clearly:

Here's a second example of that technique in a physical model to try to show how the sail sections can be connected using hinges:

Here's another where layered plates are used to provide more depth and contour:

And one more example of the same technique:

I personally like the aesthetic of studs showing in those examples, but you could also smooth your sails out using tiles and curved slopes if you'd prefer.

# Answer
> 5 votes
An official example from 2020 is seen in the 31109 Pirate-Ship using plates and curved panels:

---
Tags: building, piece-usage, shapes
---


title: What is this old wheel brick?

text:
# Question
Title: What is this old wheel brick?
What is this old wheel brick? Wheels are also available in about the half size. They have metal axles.

# Answer
> 6 votes
There are some variants registered on bricklink, but judging by the name and the presence of the brick in the middle, I guess the closest is: Wheel with 12 Studs and Axle Cam with Light Gray Tire Smooth - Large (715a / 36)

The small version you mention is probably: Wheel with 4 Studs and Axle Cam with Light Gray Tire Smooth - Small (7039b / 132-old)

# Answer
> 3 votes
Henrik covered wheels, so I'll just mention the brick used to attach these - Brick, Modified 2 x 4 with Wheels Holder, Trans-Clear Bottom

As noted on Bricklink there could be some variations of this brick:

> Several versions of this brick exist. Bush colors have been reported as red, black, milky white, and mixed colors, as well as a version missing the middle bush.

---
Tags: part-identification
---


title: Identify these windows/doors

text:
# Question
Title: Identify these windows/doors
I have these old windows. I am unsure if they are even official lego.

# Answer
> 3 votes
LEGO logo is visible inside hollow studs on genuine parts. While it is hard to identify if pictured items are genuine LEGO parts, such elements have been produced as LEGO:

Window 1 x 6 x 3 Panorama with Glass

Window 1 x 3 x 2 could be either one of these.

Door 1 x 2 x 3 Hinge on Left

Window 1 x 1 x 2 could be in two versions: with integrated glass (single piece) or with glass that can be attached (two pieces together).

# Answer
> 1 votes
Without a closer inspection I can't say if yours are genuine, but LEGO has made windows that look like that. Several (most?) variants (including all of yours) can be found in e.g. Ten Windows and Doors, White

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


title: What is this piece?

text:
# Question
Title: What is this piece?
I found this in my lego collection and can't find the name or id of the piece.

# Answer
> 9 votes
This is part #30092

Minifigure, Utensil Underwater Scooter Octagonal with Handles

In black, it appears in three sets

---
Tags: part-identification
---


title: Putting tires onto axles

text:
# Question
Title: Putting tires onto axles
I have vintage Lego sets (1970's and '80's). I absolutely cannot get the tire to fit completely over the axle. Should I try grease or hot water? I know this is the correct tire because I have some that already have the tire over the axle. Please help!!

# Answer
From my experience with tires you mention is that they don't sit symmetrically when placed improperly as they should be. Try going around the tire and pulling it slightly outwards as well as twisting a little from the side with larger outside diameter to center.

This happens with newer sets also.
> 2 votes

# Answer
The small tires Tire 14mm D. x 4mm Smooth Small Single , fit the brick on the left side Brick, Modified 2 x 2 with Wheels Red for Single Tire

not the plate on the rightside Plate, Modified 2 x 2 with Wheels Red

you will need different tires for that one
> 0 votes

---
Tags: building
---


# Question
Title: Can the Hogwarts Express train be motorised?
Can a Power Functions motor be fitted into the LEGO "Hogwarts Express" train? I have a spare motor and battery box and would like to fit them into this train.

# Answer
> 3 votes
I'll assume you mean the most recent Hogwards express but this applies to most trains:

The simplest way to motorize most Lego steam engine sets that weren't made for motorization is to rebuild the coal car to sit on the train motor and contain the battery box. This typically results in a somewhat oversized coal car, but it's not ridiculously sized. If you are using the new Powered Up components, you don't need an IR sensor and you're done with just the battery box and motor. If you're using the older IR Power Functions you need to place the IR sensor somewhere: this typically involves rebuilding part of the locomotive. If you have the Power Functions train motor, but don't want to use the IR sensor, you can use the rechargeable battery box which has a built-in speed control switch. The downside is you have to catch the moving train to turn it off.

Building a powered self-contained locomotive is challenging as most steam locomotives are not wide enough to conceal a battery box, and the train motor isn't well suited to the typical spacing of the steam engine train wheels. Not to mention that its speed assumes small train wheels, so the larger wheels will spin as fast, but because of the larger diamter, the train will be faster. It's possible, but tricky, to build a steam engine where the front wheels use the train motor: I did it, but there are serious technical challenges to making it run reliably. I ended up having to switch the large wheels from a "flange, no-flange, flange" driver configuration to a "no-flange, flange, no-flange" configuration, so that the locomotive could go around corners.

---
Tags: trains, power-functions
---


title: Can you help me identify this part?

text:
# Question
Title: Can you help me identify this part?
After a lot of circus and calisthenics with a magnifying glass and lamp, I'm still unable to read the part number. I've also clicked thru' about 180 pages of LEGO 'Pick a Brick' and didn't find it there.

Could someone please help me identify this part number? Apologies in advance for my failing eyesight :)

# Answer
> 8 votes
This is part 11458 Plate, Modified 1 x 2 with Pin Hole on Top. Much easier to find on Bricklink than by scrolling through Pick-a-Brick. Welcome to Bricks.SE!

# Answer
> -4 votes
That is a cable guide. you attach it to your house when you want to string your telephone or internet cable from the low-hanging utility wires. It provided tautness for the cable. I mean, not real tautness but enough so the cables don't hang.

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


# Question
Title: Complete set of 2004 Knights Kingdom card images?
Back in 2004 LEGO released a Knights Kingdom line of sets with trading cards for a trading card game. Those trading cards had some pictures and story information on them.

I was able to find pictures of most of them on BrickLink, but cards 50, 55, 62, 67, and 76 do not have images (although I did find a picture of 76, shown above).

Is there anywhere I can find a complete set of images, or at-least the images not available on BrickLink?

# Answer
Card 62 (Gargoyles) can be found near the bottom of this page: http://www.mikerayhawk.com/knights\_kingdom.htm
> 2 votes

---
Tags: piece-information, castle
---


# Question
Title: Please identify the set(s) that these come from
I have bought an auction lot of LEGO packs. I thought that I'd be able to identify the instructions from the QR codes on the bags, but apparently not. Is anyone here able to help?

Slightly better photos:
(http://www.imagebam.com/image/f8759e1346605880)
(http://www.imagebam.com/image/9b92721346606001)
(http://www.imagebam.com/image/6a46d51346606118)
(http://www.imagebam.com/image/89c6771346606190)

# Answer
Ho Ho Ho!

Your four sealed bags (from first through third images) are **Mr. Claus and Mrs. Claus**

Building instructions at lego.com
> 5 votes

---
Tags: set-identification
---


# Question
Title: Can't figure out what set these marvel-related bags belong to
I can't figure out what set these bags go to. I see an Iron Man minifigure in one of the bags and the bag has 741R9 on it.

# Answer
A distinctive items in Bag 1, Trans-Light Blue -Dish 6 x 6 Inverted (Radar) Webbed Type 2, exists in 15 sets.  of these contain Iron Man

Of these Set 76125-1: Iron Man Hall of Armor also contains the Bright Pink and Lime Green round 1x1 plates seen in Bag 3
> 8 votes

---
Tags: set-identification
---


title: Which is faster: M motor or XL motor?

text:
# Question
Title: Which is faster: M motor or XL motor?
I understand that the M motor has an adequate amount of speed, and the XL motor is best known for its torque. But is the XL motor really faster than the M motor? Or is it the other way around? I am asking this question because I recently saw the L motor, and one reviewer said "It has the speed of the M motor but the torque of an XL motor." I am assuming this means that the M motor is faster...?

# Answer
> 15 votes
**XL (8882):**

It delivers a maximum torque of 90,4 mNm (600 mA). Without load its rotation speed is around 220 rotations per minute.

L (88003):

It delivers a maximum torque of 45,4 mNm (450 mA). Without load its rotation speed is around 380 rotations per minute.

M (8883):

It delivers a maximum torque of 40 mNm (300 mA). Without load its rotation speed is around 380 rotations per minute.

# Answer
> 6 votes
Theoretically, in terms of power (speed • torque), the XL Motor is faster than the L Motor and M Motor. The reason being, you can gear up the XL Motor 2:1 and have the following output: running torque of ~7 N.cm & rotational speed of ~290 RPM. However, a small amount of these measures will be lost due to friction and decreased efficiency (by transferring drive through gears). Regardless, comparing these measures to the normal output of the M Motor — running torque of ~3.63 N.cm & rotational speed of ~275 RPM; and the L Motor: running torque of ~6.4 N.cm & rotational speed of ~272 RPM — and we have a clear winner, as far as running torque performance goes. Also, it is worth mentioning that the XL Motor has significantly higher efficiency than both the L Motor or the M Motor.

RPM measurements listed here are the loaded characteristics, not no-load. This is why the RPM numbers listed here are lower than what others have said.

Torque and speed measurements are according to http://www.philohome.com/motors/motorcomp.htm

# Answer
> 1 votes
It really depends on what you're going to be using it for. I'm in the middle of motorizing the fancy branded Lego Porsche and I was gonna use a couple of L Motors to drive the wheels and a servo to handle the steering, but after some research I found that because of all the gears going through the gear selection and drive-train, a powerful amount of torque is required and as Damon very correctly stated, the XL Motors are much more efficient in terms of performance. You might not be getting the same speed but you'll end up regretting buying the L motors due to their lack in torque. To solve this issue with my Porsche I just used a BuWizz controller instead of the old IR setup for more speed, flexibility and less weight as I don't need a receiver.

# Answer
> 1 votes
I bought an XL-Motor a couple of weeks ago, but when I saw a video of the M-Motor I knew it was faster. It seems to be that the XL-Motor can pull so much more due to the increase in the size of the whole motor but takes a lot more time to do a full 360-degree spin, and for the M-Motor it takes about less than a second to do a whole spin. If you want to buy a motor due to its speed but lack in torque, buy an M-Motor. If you want to have a stronger motor that won't get jammed easily, buy an XL-Motor.

If you already have an XL-Motor (or L-Motor) and you don't want to buy another (M or L) motor just increase the gear ratio. Take a huge gear wheel and get a small gear wheel and connect them to your build. Basically what is happening here is the big gear wheel is taking longer to make a whole 360 degrees spin and while it's trying to do that the small gear is going twice as fast as the big gear and therefore makes it go fast.

Here is an image of the motor:

---
Tags: motor, power-functions
---


# Question
Title: Distance Learning Mindstorms web-based software
I am a Technology education teacher from NJ and I use Lego Mindstorms for my 8th-grade robotics class. Since we are doing distance learning (teaching from home) my students have not been able to continue their curriculum as the software and robots are at school. Is there a web-based program where the students can code with block-based coding (not scratch) like in the normal downloadable software and run virtual tests of their code? Kind of like the virtual brick or virtual world software you can purchase but a web-based version so my students can still learn how and explore Mindstorms like we would in the classroom. Any suggestions?

# Answer
Here's Microsoft Makecode. It is full of tutorials for the EV3, such as:

• Example programs

• How certain sensors work

• How certain code blocks work

• Instructions for EV3 robots

• And much more.

Is this what you're looking for?
> 1 votes

# Answer
There is a program called Robot Virtual Worlds: http://www.robotvirtualworlds.com/

... but it is a downloaded program vs. web based. You might be able to use a remote desktop sharing program (VNC, Skype, Zoom, MS Teams, Team Center, etc.) to access remotely, or contact them if they're considering a "cloud hosted" option.

They do offer a free trial, so you can always experiment to see if it works at all for you.
> 0 votes

# Answer
Perhaps you should try CoderZ. I think that it would fill your requirements. An online coding environment where you can also see the robots virtually move as they have been programmed. I have never actually used this before but I think that you should have a look at it. Happy Programming.
> 0 votes

---
Tags: ev3, mindstorms
---


title: Can you identify these railings?

text:
# Question
Title: Can you identify these railings?
Can anyone identify the railings around this building? I thought they might be ladders placed horizontally, but I don't see any clips.

# Answer
This could be either Fence 1 x 4 x 2 Spindled with 2 Studs

Or Fence 1 x 4 x 2 Spindled with 4 Studs
> 3 votes

---
Tags: part-identification
---


title: Partial Truck needs to be identified

text:
# Question
Title: Partial Truck needs to be identified
I've acquired a partially built truck (2 sets wheels so not huge), of which the bottom section is all I have (from the floor down). There is a transfer on both sides (on red bricks, which made me think of a fire truck, but no luck). This sticker looks like an advertisement or sponsorship logo you might see on a vehicle. It says Octan, then Tele (with the top of the T being a telephone receiver), then a white square with a black border with the initials CB in black typeface in it. It also has a tow hitch on the rear. Any ideas what model number I've got?

# Answer
Based on your description of the brick with “transfers”, which I assume are stickers, there is only one set that has Octan and Tele logos on it: 60084 Racing Bike Transporter. This set seems to match the rest of your description as well.
> 6 votes

---
Tags: set-identification
---


# Question
Title: What LEGO set is this bag with minidoll?
Can anyone help me identify the set that these parts come from?

The bag is number two.

# Answer
> 9 votes
I believe this is Heartlake Hot Air Balloon (41097).

The red striped torso only appears in a few sets, and it's fairly obvious from the rest of the parts which one this is.

Here's what that bag builds specifically:

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Tags: set-identification
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# Question
Title: How to update item prices in a Bricklink store?
I have a BL store in which I have parted out a huge collection of LEGO sets. During the part out I set the item prices so that they match the average on BL. However, after a while, I noticed that due to the price changes, some of my items became significantly cheaper or more expensive than the average. Neither of them is desirable. Is there a way to update the pricing of my store including all items to match the current BL average prices?

# Answer
> 5 votes
The easiest way is to download and install Brickstock (www.patrickbrans.com is the site it is located on AFAIK), pay for the upgrade to the full version ($20 via paypal) and then download your entire store inventory, do `ctrl`-`A` `ctrl`-`G` which downloads the current prices, and use the “update inventory in bricklink” option from the File menu to set the new prices.

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Tags: bricklink
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title: How can I make my LEGO engine go faster

text:
# Question
Title: How can I make my LEGO engine go faster
I have a LEGO engine powered by a PF XL motor but I didn't realize until now that the motor is not that fast and that even when I increase gear ratio the gears always get either unattached or jammed.

What should I do?

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## Update:

Thanks to mindstormsboi and Alex I was able to change the design of the engine to the following. It works much better now.

# Answer
If you need a fast motor but not having too much torque, yet powerful enough \- consider using a PF L-motor. It has roughly half of the XL-motor's torque, but twice as much rpm.

The PF XL-motor has high torque, considering its intended application with LEGO. This is known to cause some serious damage to gears if the assembly isn't rigid enough. It is essential to have your gears braced properly from both sides. Otherwise your gears will be slipping and/or grinding under load. In your picture you have your gears braced from one side only - this will cause you problems. You need to construct **rigid bracing** from the other side as well.

I find Sariel's Gear Ratio Calculator useful for finding the right gears for your application.
> 2 votes

# Answer
To me, that does not really look like a proper gear train. I recommend that you line up all your gears on a technic beam and stick axles through them (and obviously bushes so they don't fall out). You also need to be using the correct gears. In other words, the ones you're using seem incompatible with each other, so you need to find gears that are designed to work together such as this gear with this gear combined and this gear with this gear combined. Also, make sure that any other Lego bricks are not interfering with the gear train. More info about gear trains.

Here is an example of what I mean:

As you can see there are no bushes attached to the axle, but that's because I'm using axles with stop. I lined up my gears on a beam without putting them too far or too close from each other and now they freely spin with no problem.

You also wonder how to make your engine faster. If using one single big gear and another small gear together is not fast enough, try adding some more. I will show you one way of doing this step-by-step.

Above is one big gear and one smaller gear, which is considerably faster than without any gears at all (unless you use the smaller gear as input gear, which gives opposite effect). If it is not fast enough for you, then we will expand the gear train to make it faster.

Now there is another big gear on top of the small one. This is because another small gear will follow after it, which will be almost twice as fast as the previous small gear.

Now there is the smaller gear. As I already said, it will be faster than the previous one due to the size of the other gears following it.

Now we put a bush under it to prevent it from slipping. You might think I could've put another big gear there instead, but *no*, I can't, because it will ruin the gear train and jam it up. The gear train will therefore continue on the other side of the beam, like so:

A big gear was placed on the other side of the beam to continue the gear train, and of course, a smaller gear will follow after it. But keep in mind that the smaller gear should be on the *right* axle from the bigger gear, not the *left*, because the axles on the left are already controlled by gears and you may end up twisting the axle or breaking the teeth off of the gears above them. It is also worth noting that putting too many gears will make it too hard for the motor to move them due to the heavy load of overall friction between them, so don't try to make it too fast.

**Update:** Here's another picture of some example gear trains taken from this answer:

You can also use gear links to make your gears faster while they are spread apart, as seen here:

Just note that there are different variations of those gear links which are designed to work with different gears.
> 1 votes

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Tags: technic, gears, gearing
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