# Question
Title: I have bags 2 and 3 of the LEGO group 2011 but no instructions, can anyone identify these?
I have bags 2 and 3 with the number 135149 on them but didn’t get instructions (found them at goodwill). They have red, brown and green, some gray and black bricks, with guns, a cowboy, an Indian, a cowgirl, a horse and others.

# Answer
Looks like set 79108 Stagecoach Escape by matching the horse, saddle and the minifig head.
> 5 votes

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Tags: set-identification, instructions
---


# Question
Title: Parts for "Simple Machine" book by Isogawa-san?
I would like to make some models from The LEGO Technic Idea Book: Simple Machine by Yoshihito Isogawa.

It seems the author is using parts of different "Technic" sets.

Could you advise where can I get parts (or ideally a set) to make the models for the book?

# Answer
There was a lot there, but the very last sentence from your *Amazon* link mentions to visit the *No Starch Press* website for a list of the special parts used in the book.

There the website includes all three books from the author's LEGO Technic series:

* *The LEGO Technic Idea Book: Simple Machines.* (Digital PDF of book *here*.)
* *The LEGO Technic Idea Book: Wheeled Wonders.*
* *The LEGO Technic Idea Book: Fantastic Contraptions.*

All with a few set recommendations directly from the author, where he suggests sets that have a wide range of parts in single set purchases.

For parts left over, he offers a reference list with colored pictures of each part, and purchasing links to *Bricklink.com*.
> 5 votes

# Answer
As far as I know Isogawa uses a large range of colored bricks to show the mechanisms. There is no single real set you can buy that contains all the parts. If you really need to have the exact same colored bricks you would need to look into buying them separately. However this might get a little tedious or expensive. Any other bricks in common colors would work nicely as well.

There are many ways of buying the needed bricks separately. You may wish to check Bricklink, Brickowl or LEGO Pick-a-Brick selection.
> 3 votes

# Answer
www.bricklink.com is a great place to find parts!
> 1 votes

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Tags: technic, part-identification, piece-information, books
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# Question
Title: Is this black and red speedboat model from an official set or a MOC?
Please help me: is this from an official set or an MOC?

# Answer
This is part of 6679-1: Dark Shark
> 10 votes

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Tags: set-identification, moc
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# Question
Title: What is this old dark grey LEGO wedge piece with a grooved handle?
Here is an odd piece that I have found - any idea what it is? 2x2 plate is shown for scale.

# Answer
It's a *LEGO* brick Separator tool. Mostly used to preserve the structural integrity of the human nail, teeth, gum line etc...

Watch the classical use of it *here*.

*Here*'s a recent post of some unorthodox uses of the Separator tool.
> 6 votes

# Answer
To expand on a previous answer, it is the original brick separator that was produced between 1996 and 2011 in two colors. It was replaced in 2012 by a different part with the same name and purpose but slightly different features.
> 1 votes

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Tags: part-identification, piece-information
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# Question
Title: What is this 2×8 plate slotted, rectangular studs and a hole in the middle?
Please help to identify this part. What is its use?

# Answer
This is

Part # 767 : Train, Track Sleeper Plate 2 x 8 without Cable Grooves

or

Part# 4166 : Train, Track Sleeper Plate 2 x 8 with Cable Grooves

depending on the cable grooves.

It is used to attach train tracks
> 3 votes

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Tags: part-identification
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# Question
Title: Is this red axel bushing an original Lego part?
Is this an original Lego part? Technic maybe?

# Answer
> 2 votes
This is

Part# x1299 : Technic Bush Old 1

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Tags: part-identification, piece-information
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# Question
Title: Please help to identify the set this sticker belongs to
Please help to identify the set this sticker belongs to.

The sticker is on both sides of the ensemble.

# Answer
Bricklink lists this as a sticker over assembly

Part # BA55pb01 : Stickered Assembly 4 x 1 x 2 with Arctic Technic Logo Pattern on Both Sides (Stickers) - Set 8640 - 2 Slopes 45 2 x 1, 1 Slope, Inverted 45 2 x 1

From

8640-1: Polar Copter
> 2 votes

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Tags: set-identification, sticker-identification
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# Question
Title: Is this black two-sided clip an original part made by LEGO?
Is this an original LEGO part? Maybe Technic? See the cup for size comparison.

# Answer
The black one is a playmobil part, used to link fort wall part together. I think the cup is playmobil too.
> 7 votes

# Answer
I don't recognize this part as produced by LEGO. On another thought, pictured black part has rough edges (low quality), which is unheard for LEGO.
> 2 votes

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Tags: part-identification, clone-brands
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# Question
Title: Cleaning Bricklink pieces bought as "new"
I'm just preparing my first Bricklink order and I've got a simple question - Is there a reason to clean pieces bought on Bricklink which were sold as "new"?

# Answer
> 3 votes
No. 10 out of 10 orders were in perfect condition. Cleaning the bricks would have been a waste of time, and would have added unneccessary scratches.

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Tags: piece-information, cleaning, bricklink
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# Question
Title: Is there a Ubuntu Linux LEGO instruction manual creator?
Is there a good LEGO instructions manual creator for Ubuntu? I can't seem to find one.

Also, are there any online ones?

# Answer
> 5 votes
LeoCAD is available for Linux based OSs as well as Windows and Mac, and supports Step creation as well as general model creation.

There are a few other workflows detailed in this answer to a similar question.

# Answer
> 4 votes
In case you have made your model with LDraw based software with all necessary steps already you can use LPub3d to create building instructions. There is a bit of a learning curve to make your instructions look right with required features. But then it makes them look almost like made by LEGO.

There is even an Ubuntu native \*.deb package available to download. No need to compile from source.

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Tags: software, instructions
---


title: Where to buy rare old LEGO sets?

text:
# Question
Title: Where to buy rare old LEGO sets?
Does anybody know a good place to buy rare old LEGO sets?

I'm looking specifically for old "pneumatic" featured LEGO Technic sets.

# Answer
If you already have a specific set in mind BrickSet provides links to ebay, bricklink, etc. to get a good overall idea of what prices look like. BrickSet also has a tag for pneumatic sets. I use it for tracking my wish list and what I already have.

I usually end up buying the sets or parts on BrickLink, but I'm not shopping for old sets that often. There is much less sketchy stuff happening in BrickLink than on ebay. You can find better prices if you're patient with ebay, but the BrickLink prices are often totally reasonable. BrickLink also functions as the canonical list of sets and which parts are in which sets. Sites like BrickSet automatically synchronize with it.

Looking at one of the oldest pneumatic sets - 8851 Excavator \- ebay has it for $12 & $12.99. BrickLink's prices start at at $39.67 so I'd probably see if the ebay seller's have high-enough ebay reputation to deal with. In this case ebay might even require less patience than bricklink.
> 2 votes

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Tags: technic, shopping, sets
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# Question
Title: What are these grey scoop-shaped parts with a hole for an axle?
I got these in a lot that I bought and I have no idea how to identify them. They have dates from 05 and 02, but no part numbers.

# Answer
This is:

Part# 42042 : Light Gray Bionicle Krana Holder 3 x 4

Keyword: 3 x 4, Color: Light Gray

it appears in 13 sets
> 3 votes

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Tags: part-identification
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# Question
Title: Please Help Identify These Star Wars Sets
I guess these are StarWars sets, please help to identify

# Answer
1.Set# 75172 *Y-Wing Starfighter*.

2.Set# 75013 *Umbaran MHC (Mobile Heavy Cannon)*.

3.Set# 75003 *A-Wing Starfighter*.

(Note: Canopy and gun turret on KETCHUP colored ship belongs on MUSTARD colored ship.)

See ya *Fabian*!
> 4 votes

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Tags: set-identification, star-wars
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# Question
Title: Is it possible to sand/polish LEGO bricks?
I have an old white and rare brick which got scratches and dirtying which I cannot wash away. Any ideas on how to clean it? I thought about fine sanding or polishing but I am afraid that I damage the brick.

# Answer
It is definitely possible, since ABS is a plastic that can be either mechanically or chemically affected. Cleaning bricks is a well-studied field, you will find useful information regarding this topic all over the internet, including here.

Polishing LEGO bricks is less heard of, but can be done either mechanically (another link) or chemically (another link). Note though, that any kind of polishing includes either removal or rearrangement of material, so the chance of damage is definitely not zero in any method. I'd suggest starting with the gentle and precise methods (file, hobby knife, fine sandpaper, etc), and only progressing to more drastical methods (acetone) if they fail.

When using acetone, be especially careful, as the vapours can't be easily controlled, and they are flammable (can burn down your house), poisonous (can kill you and your family), and can even melt the entire brick if given the chance! Of course the dangers depend on the amount and ventilation, but some of the above links depict clearly dangerous settings, uses and amounts.
> 4 votes

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Tags: cleaning, piece-usage
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# Question
Title: What do I need to connect an old RCX 2.0 to a computer and is it worth compared to just buying a new one?
From a friend I got some Lego, including an old Mindstorms package (RCX 2.0 as I already found out). It's my first time with the Mindstorms "eco system".

I already found out that I need some kind of IR sender for the connection to a computer -- sadly, the original one is missing. Now I'm trying to find out what I actually need to be able to do something with the whole stuff and if it's worth at all to put a lot of effort into it (or if it'd be easier/cheaper to just buy an up-to-date Mindstorms package).

* what IR sender should I buy (I saw that the original ones are available for cheap, but if possible I'd like to buy up-to-date or more generic hardware that I can also use with newer Lego systems or ideally also non-Lego "endpoints")
* What software do I need in general?
* Are drivers (if needed at all) still compatible with up-to-date computer systems?
* Do I need some kind of firmware updates for anything?
* are the downloads on lego.com (https://www.lego.com/mindstorms/downloads) compatible with RCX?

I'm having access to computers running Windows 10 and Ubuntu (both 64 Bit) if that matters.

# Answer
Modern hardware/driver support for the RIS is limited, but it's definitely possible to get it working again.

The main obstacle is transmitting programs to the Lego RCX brick. The RIS 2.0 came with a USB IR Tower, but the driver does not work on 64-bit Windows. There is also a Serial-port IR Tower available, which works perfectly if you have a 9-pin serial-to-USB adapter.

Here's what you need to buy (they're all very cheap):

With the (included) driver installed, the USB-to-Serial will create a virtual COM port in Windows. If it's relevant to you, you can check the number of the COM port in windows Device Manager.

On the software side of things, you can code for the RCX using Java, NQC (C-like syntax, but much simpler), or the original Lego graphical programming language. You don't need to install any Lego software if you plan on going with one of the 3rd-party Java or NQC options.

If you do want the Lego programming software but you don't have the disk, you can download an ISO disk image from this guy's share. The Lego software and its installer ran fine on my machine (64-bit Windows 10), with a small caveat: At the end of the installation process, it attempts to install the USB tower driver. When this happens, you need to go to task manager and KILL the installer process, because when the driver (inevitably) fails the whole installation rolls back. If you're having trouble it might also help to right click on the Setup.exe -\> Properties -\> Compatibility and run it in compatibility mode for Windows 98.

Inside the Lego software, you should select the Serial IR Tower when prompted because you want it to use the virtual COM port the adapter provides. You can also set the COM port in the Settings from the main menu screen.

When you first install the software it will try to force you to do tutorials before you can actually do the "freestyle" programming. But you can double-click any greyed-out option to enable it.

And as always, if you need more help you can always post back here in Bricks SE. Good luck!
> 4 votes

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Tags: mindstorms, rcx
---


title: 135149 is all info I have

text:
# Question
Title: 135149 is all info I have
My son got some LEGO bricks in a bag as a present from good will, but no instructions were included. The only info I have are numbers on the bag 135149 and 2011. One of the small pieces has 62361. But no luck to have any info with numbers.

# Answer
2011 is probably just the year the bag was copyrighted, not anything useable to go on.

The other number on the bag is not really useable either.

Part 62361 is Vehicle, Mudguard 1 1/2 x 6 x 1 with Arch a part that has been in 98 sets. There are probably numbers on most other parts in the bag too, but pictures are usually better.
> 2 votes

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Tags: set-identification
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# Question
Title: Help identifying set from 3 sealed bags with Star Wars figs
I got these three bags in a lot. Looks like there are two snow troopers and bag 4 has a bunch of fluorescent green circle pieces. Any help would be appreciated for this first time poster.

# Answer
> 4 votes
Welcome to Bricks.SE! Based on the 10 x 3 Wedges and your description, these bags likely belong to 75100 First Order Snowspeeder:

The instructions for this set are available here:

https://www.lego.com/biassets/bi/6136428.pdf

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


title: Where to get 3D files for LEGO bricks?

text:
# Question
Title: Where to get 3D files for LEGO bricks?
I am constantly in search for a particular rare brick from the 1990's which is ridiculously expensive on BrickLink and also hard to get. So I am thinking about printing it on a 3D printer to be able to finish projects. I understand, a blasphemous behaviour. Please let me know where to get the needed 3D file.

# Answer
The canonical location for 3D models of LEGO bricks would be LDraw, with its huge catalogue of official parts.

Another resource specifically catered to the 3D printing community is PrintABrick. Their library is not as big as LDraw's, but they offer ready-to-print STL files.
> 8 votes

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Tags: 3d-printing
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title: Can the scabbard hold a castle sword

text:
# Question
Title: Can the scabbard hold a castle sword
I wonder if the Dark Gray Minifigure, Weapon Sword, Shortsword part No: 3847a fits in the Minifigure, Utensil Scabbard with Shoulder Strap part No: 95348

Scabbard on bricklink

Sword on bricklink

# Answer
> 1 votes
Yes, it does, and it fits beautifully! In fact, it's one of my favorite combinations as the sword is not too long and thus doesn't drag on the ground.

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Tags: piece-information
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# Question
Title: How does one become a LEGO® Certified Professional?
The LEGO Group's official website has a page speaking about the "LEGO® Certified Professional" designation that a person can earn. It states:

> LEGO® Certified Professionals is a community-based program made up of adult LEGO hobbyists who have turned their passion for building and creating with LEGO bricks into a full-time or part-time profession.
>
> LEGO Certified Professionals are not LEGO employees, but they are officially recognized by the LEGO Group as trusted business partners.
>
> Each LEGO Certified Professional is selected for the program based on his or her:
>
> * Building proficiency
> * Enthusiasm for the LEGO brick and building system
> * Professional approach towards other LEGO fans and the broader public

What seems to be missing from this page is information on the exact *process*.

**How does one become a LEGO® Certified Professional?**

* Is there an exam that someone can formally request to sit at a LEGO Store or corporate headquarters?
* Is there a formal portfolio evaluation process?
* Is one required to amass a certain number of course credits in engineering, design, polymer chemistry, and/or education?
* Is the program invitation-only?

I did find an interesting article giving biographies of several LEGO® Certified Professionals, but it doesn't go into depth about *how* they specifically came to become certified. It mentions that "So if you are thinking about becoming a LEGO Certified Professional one day, it is a good idea to study their work and follow in their footsteps.", which isn't exactly *helpful*. If I want to become a physician, I need to be looking in to how to get admitted to medical school, not reading biographies of Galen and Jonas Salk.

I also found a testimonial of someone claiming to have earned the certification in 2010, and it consists of the author talking about how awesome the certification is and what they plan to do with it rather than explaining the process that they went through to earn it. This also makes me suspect that the requirements may be arcane or not well known.

Whether I, or anyone here, has or could ever achieve the level of skill required for the certification is not part of the question - the question is how one could *try*, even if the result is failure - rejected portfolios, failing exam scores, eternal banishment to Ice Planet 2002, etc.

# Answer
First of all, there needs to be an opening for one, which typically means LEGO feels they need more Certified Professionals in a particular region.

The most-recent opening was last November and was presumably filled in December. For this most-recent one, LEGO had a posting on their website where people could apply, and they made a small announcement to fan communities via their ambassador program.

Assuming this is how future certified professionals get selected, basically becoming a certified professional means applying to an opening in the program, and getting accepted (I strongly suspect anything beyond the initial application is protected by an NDA).

Unfortunately, I don't know what specifically was asked from potential applicants to the most-recent opening, but if you are interested in perhaps applying you should be on the lookout for future openings. In the mean time, consider joining some RLUGs or RLOCs and making some connections, to gain a reputation as a builder and perhaps be recommended to apply when there is an opening.
> 3 votes

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Tags: lego-group, afol, lcp
---


# Question
Title: How to connect an NXT brick to the LEGO programmer application on an iPad?
Can you connect a NXT brick to an iPad via either USB cable or Bluetooth? For me neither seem to work even though the EV3 brick (and the LEGO programmer application) should be backwards compatible.

I can connect the NXT to the iPad: both are displayed by the other device as connected. But in the LEGO programmer, the NXT does not show up as an available brick.

I have also tried to connect with 2 USB cables that have a male to male connection in between. There seems to be no option for that at all in the LEGO programmer.

Does anyone have another idea how I can get these two devices to communicate and download files?

# Answer
> 1 votes
The NXT only works with the EV3 desktop software (for Windows and Mac) and only via USB.

I'm not aware of any way to program NXT using an iPad (or Android, or Chromebook).

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Tags: ev3, nxt, bluetooth, ios
---


# Question
Title: Hacking the Bluetooth motor in the motorized LEGO® DC Super Heroes 76112 App-Controlled Batmobile
I'd like to hack the receiver / motor so I can control it from my Mac (or a PC if there is no other way).

Recently LEGO released an app-controlled Batmobil - product detailed are here: https://shop.lego.com/en-US/App-Controlled-Batmobile-76112

The Bluetooth receiver (LEGO Part #6253628) can connect to an app, in our case, an iPhone. I tried to see if it was visible in the Bluetooth elements to connect to, and nope... I cannot also find any MAC address on the receiver itself.

Any hint or clue?

# Edit #1

I am looking for a way to connect to the Bluetooth receiver and be able to program it in **Python** (or C/Java...), but not a GUI.

# Answer
> 7 votes
There's a node.js library that can connect to the Move Hub and control attached peripherals:

https://github.com/nathankellenicki/node-poweredup

This should allow you to write scripts and programs that can control the motor from your Mac.

# Answer
> 1 votes
Check out with nRF Connect app -\> if you can find it with it, you can read services and characteristics of this lego peripheral and based on that control it. Good luck!

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Tags: bluetooth, powered-up
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# Question
Title: Can you identify this handle-like LEGO piece?
Can anyone help me identify the name and part no of this piece? I’ve tried looking in BrickLink for handles, guns, bars. Can’t think of any other way to describe it.

# Answer
> 6 votes
Definitely on bricklink: https://www.bricklink.com/v2/catalog/catalogitem.page?P=60849#T=C However, not as a minifig weapon but a minifig utensil

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Tags: part-identification
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# Question
Title: Website to help identify set(s) from approximately 20 bags of LEGO?
I bought a storage unit at auction. There were approx 20 sealed bags of LEGO in the unit. Each bag has a number on it. I'm trying to find out if I have a complete set so I may sell them. Is there a site I can go to to find out? Thank you.

# Answer
> 2 votes
Brickset is a database of Lego sets. You can search for set numbers and see if they match what you have. It also provides full parts lists so you can see if your kits are complete or not.

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Tags: set-identification
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# Question
Title: Why are different ID informations printed in the inside of the same sort of bricks?
While sorting old bricks I observed that the inscriptions printed inside show a different coding. As you can see the outside it is always a ordinary "1x2 tile with groove in good old Light Gray (item number 3069)". The inside instead appears very different.

Reading from left to right it says:

```
15; (c) LEGO; 032 #
LEGO; 3 #
(c) LEGO; 16; 35; 3069 #
8; (c) LEGO; 032 #
LEGO;  1 #
3069; 36; 17; (c) LEGO #
5; LEGO; 3; 1 #
LEGO; 11; pat. pend. #
LEGO;  11 #
3069; 36; 9; (c) LEGO

```

Why is that so?

You can also see that most of the bricks got on one half of the inside a yellowing. It seems that the effect is not only accruing on the surface but really eating its destruction through the material which I was not aware of.

# Answer
Has to do with copyright patents of the brick design, and warding off general infringement. Other numbers. I don't know. Design references?

Your *(c) LEGO* = © symbol, or the word 'Copyright' or abbreviation 'Copr.'; The year of first publication of the copyrighted work; Identification of the owner of the copyright, either by name, abbreviation, or other designation by which it is generally known.

---

My personal rule when buying any bricks from Bricklink.com when it comes to colors and brick type.

I use a high number of finishing bricks to cover up studs, so I try to get all tiles new.

When it comes to colors be very weary of old beat up pieces, which will ruin the look of your masterpiece. Biggest offenders for me are White, Yellow, Light Gray, and old Blue pieces that will crumble with the slightest pressure in your hand. White/Yellow always get bought new or in bulk from a *LEGO* store.

I tried your recent chemistry lab experiment to whiten some of these older pieces with hydrogen peroxide with mixed results. For me it's just better to buy new in bulk from a *LEGO* store if posible.
> 1 votes

# Answer
On newer pieces (maybe also the newest of the ones you show), there's a number identifying the mold and one identifying the position in the mold, allowing LEGO to trace a problem all the way back and examine the mold if a high number of errors seem to come the same mold.
> 3 votes

# Answer
While we might not know all stories behind additional numbers it has been discovered that in later years LEGO use numbers to designate the mould they are using. With massive productions moulds tend to wear out and need to be replaced. This case is well known with basic 2 x 4 brick aka. 3001, which are produced in large amounts. Latest numbers embeded on the bottom of the brick are 200+.
> 1 votes

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


# Question
Title: Lego Adventurers set with bridge, board with mountains?
I'm looking to identify a Lego Adventurers set. At least I'm pretty sure it's adventurers, or a similar theme like Orient Express.

The set has a mountain board, with a river underneath. (If you own a LEGO curved road board, it's similar, except it has a river in place of the road and 3-dimensional mountains.) It's a very unusual piece, though it broke apart quite quickly unfortunately.

The piece also included a rope bridge.

The box had an adventurer wearing a hat swinging from a rope (?)

I don't have pix - it's a set I remember from my childhood and would love to re-buy.

# Answer
> 3 votes
How 'bout *Set #5986 Amazon Ancient Ruins*?

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Tags: set-identification
---


# Question
Title: Mecha Rail Launchpad Building techniques?
Another mecha question, but this time, at least I think, is not so *intense* as my last question.

I've decided to take my biggest and most ambitious LEGO project yet, a custom MOC of a Pacific Rim style Shatterdome. I plan to house each mech in it's own *private* holding pen/dock/bay, with each bay having it's own trolley leading to the center of launchpad which houses a central turntable. This turntable being used to redirect the mechs to where they need to go.

Something important to note, the mechs are arranged, in their pens, around the turntable almost in a radial, floral pattern, with the turntable at the center, almost like a sunflower.

The issue that I am facing is that I cannot come up with a design for said turntable. No matter what I try, I just can't get the turntable to *integrate* nicely with the mech sleds.

Here is a picture of the mech dock. It's a rough idea, but more or less what I am going after --\>

Here is also a fabulous picture/sketch done quickly in paint of what I am trying to accomplish --\>

As soon in the picture, there is also my attempt to create the turntable in question, but as you can see, it's not going as grand as I had hoped.

Any ideas?

# Answer
Based on your drawing and description, the closest analogy to your idea would be a railway turntable, where the mech bays would be akin to the roundhouse and the "exit" on your diagram represents the connecting railway to the turntable switching yard.

LEGO models of such structures can be found and analysed for their various building techniques to see which ideas would suit your expectations and situation.

**Rails: yes or no?** Obviously these models are designed with LEGO railway pieces in mind which might or might not be suitable for your MOC. Using the existing railway system offers a few advantages, like a complete ecosystem for straight and curved rails, wheels, carriages, switching points, couplings, etc. and might even look suitably industrial and heavy-duty. On the other hand their usage seriously limits the possible geometries (wheelbase length, minimal height of the carrier trolley, etc.), defines the look of the model and might provide challenges with the connection of the turntable and the static rails. Another option would be to use carrier trolleys with rubber wheels on a tiled surface to get around some of the above restrictions.

**Implementation of the turntable itself** The basic component is a circle-shaped, pit-like structure with a radius big enough to fit a carrier upon the rotating bridge above it and with enough depth to house the end supports, the central pivot column and the mechanism used to motorize it if needed. The central pivot and the end supports must be strong enough to hold the combined weight of a carrier and a mech on any point along the tracks on the turntable, which would mean either really sturdy supports or a carrier long enough to distribute its weight among multiple supports and the ground around the structure.

```
SIDE CUTAWAY VIEW OF THE PROPOSED STRUCTURE
                                        MAGNIFIED VIEW OF
 mmmmmm      mmmmmmmmmmmmmmmmmm       THE DRIVING MECHANISM
 oo==oo      o==o   o==o   o==o    /   ----------  -------
 ------ ----------------- ------  /         d|b3   MMMMM##
 ######  T      A      T*~MM#### <           *~~~~~MMMMM##
 ######  !      H      !  ######  \                MMMMM##
 ########^#############^########   \               #######

Legend:
# "Solid" ground
- Rail for the mecha carrier trolley
o Wheels of the carrier
= Structure of the carrier
m Feet of the mecha, or upper structure connecting multiple carriers
T End support structures
! Support structures with tiny wheels on their bottom parts
^ Suitable rolling surface for the end support wheels (rails or tiled surface)
A Central axis pillar
H Central pillar structure
M Motor for driving the ring
3 The inner gear rack of a Bucket Wheel Excavator ring
d|b A gear with a vertical axis, meshing with the gear rack ("3")
* A mechanism for turning a horizontally rotating axle into a vertically rotating one
  (like two bevel gears or a gear and a worm gear)
~ Horizontal axle

```

**End supports and their wheels** The end supports must travel along the bottom edge of the pit, supporting a great portion of the carrier and the mech, while losing not too much energy to friction. This calls for wheels, but even here we have many options:

* You can certainly use generic railroad tracks if the dimensions permit it (the radius of the pit is just a few studs larger than the outer curve radius of the LEGO rail pieces)
* For smaller dimensions the narrow gauge rail tracks might be used
* The newer roller coaster pieces could be an alternative if a suitable wheel setup can be constructed either from scratch, or built around the existing rollercoaster cars
* At least one example I have seen uses monorail tracks, if you have those, feel free to use them this way
* Tiles and road wheels are certainly the most flexible option regarding the possible diameters but they tend to have a lot of resistance compared to non-flexible wheels on rails
* Some Technic sets, like the 42054 Claas Xerion tractor, the 42082 Offroad Crane or the 42055 Bucket Wheel Excavator for example feature such turntable solutions that can be used as inspiration

**Motorization** You haven't mentioned if you'd like to use a motor to drive the turntable, but if yes, then you have a few options here as well:

* Train engine on rails as the "feet" of the end support(s)
* Motor housed in the end support(s) propelling against the wall of the pit
* Motor housed in the central column
* Motor housed in the wall of the pit propelling the turntable by its edge

The first two options require either a battery and control system built into the moving parts of the turntable itself, or wires that can feed the built-in motors from a static battery - but this option must be used with limiters or the wires might get tangled or snap. The third needs extensive gearing down to be able to handle the load and all losses without overstraining the motor. The last option avoids these problems but requires the turntable to be a complete ring with an interface suitable for propulsion (either a smooth circle that can be driven via friction from multiple rubber wheels, or a circular gear rack - The specialised parts from the Bucket Wheel Excavator or the 4481 Hailfire Droid wheels would be my first idea).

If you have any more questions, either in general or regarding a specific problem, feel free to ask - I'd love to see your project come to fruition :)
> 3 votes

# Answer
You know, I hate it when I post a question like this, but I come up with the solution almost immediately after. Let me explain as best I can...

So, I did some digging online for pictures to use as references for building this turntable I described above. By sheer luck, I stumbled across this post on LEGO Ideas for a discontinued idea for a Train Turntable MOC. The link can be found here.

On this page, I managed to download the Turntable module itself, and dissected the model left, right and center to get an idea of what I wanted to do and accomplish in this massive MOC of mine.

Essentially, the Turntable is a large long plate spinning on a central point, controlled by a gearing system that is used to rotate the assembly without actually touching the turntable itself. The Turntable itself is then surrounding by a radial pattern outfitted with rails, leading to the various mech bays I have surrounding the central turntable.

Below is a picture of the turntable outfitted with a bunch of my mechs in their respective bays.

Truth be told, the design is so blatantly simple, I'm surprised I didn't see it right in front of me in the first place.
> 1 votes

---
Tags: building, ldd
---


# Question
Title: black pants (jeans?) with silver/gray pockets and gold dot
Do you recognize these pants? Are they on Bricklink, etc.? (I looked on Bricklink and Rebrickable but couldn't spot a match.)

# Answer
This is :

Part# 970c00pb176

Hips and Legs with Gray Jacket Tails Outline and Gold Button Pattern (Lord Vampyre)

Keyword: Gold button
> 4 votes

---
Tags: part-identification
---


# Question
Title: Representing pregnancy on LEGO minifigs without a dome
So far for pregnancy I have tried a fetal carrier that I put on the minifig's back but this limits her movements. Specifically she can't bend too far in either direction and also she can't lay down the way she normally would (she would have to like bend her legs when she lays down or something to keep the fetus inside).

My minifigs don't have a hole in the belly where I can put a big white dome to illustrate pregnancy.

So what is the best way to show pregnancy without a pregnancy dome?

# Answer
The best piece to represent a round belly is the "Plate, Round 2 x 2 with Rounded Bottom" (part 2654). The "dome" pieces are way too big. Connect the rounded bottom plate to the bottoms of two "Brick, Modified 1 x 1 with Headlight" bricks (part 4070), also known as the Erling brick. Use short legs to get the total height right.

Note that the pegs on the leg pieces are slightly larger than a normal stud, so they make for a *very* tight fit in the back of the Erling brick. They do fit with some force, and they are difficult to remove.

FYI, I experimented with a few iterations, including one using a 2x2 flat tile on a bracket, and this was the version that had my non-Lego fan wife exclaim, "Oh yeah, that looks good!"
> 8 votes

# Answer
As far as I can see, most LEGO pregnancies appear to cheat, using glue or Blu Tack to attach the various elements on to the stomach of the minifig.

One example I've seen is the use of a 1x2 tile, as seen here at the Brick Testament:

In this image, Mary could be holding the tile in place, but in other images, her hands are not near enough.

Also to your point of lying down - in real life I've noticed that some pregnant women prefer to lay on their sides rather than their backs, certainly during the later stages of pregnancy.
> 3 votes

# Answer
One alternative is to use an appropriate decal rather than trying to construct something.

Image courtesy Flikr.
> 3 votes

# Answer
I usually hang the minifig back plate with knob on the front with a dome, or I use two between the torso and legs (they will fit) and attach a dome or something else.
> -1 votes

---
Tags: building, minifigures
---


# Question
Title: Help identifying a black and white 1 x 1 LEGO part with clip on top
The numbers inside this brick are 01 B02. The brick is a 1 x 1 black plate with a white clip inserted into a hole. I have searched BrickLink with no success. I have also searched Google. Hoping someone from here can help.

# Answer
Hey there *Treppy*!

This is *Part #93062c01 Leg Skeleton with Black Square Foot*.

Ya see, even the Skeletons know stepping on a *LEGO* bare boned is a no no!

See ya!
> 6 votes

---
Tags: part-identification, minifigures
---


title: Why are there extra pieces in my set?

text:
# Question
Title: Why are there extra pieces in my set?
I bought an advent calendar, with a minifig or part of a scene behind each door. Each piece is sealed in a plastic bag and needs to be assembled. Almost every bag has an extra piece in it. Is this a mistake when the pieces are being wrapped, a little bonus (yay, 2 crowbars!) or sloppy counting?

(It's extremely Christmassy - a police station, burglars with a crowbar and axe, police officers with handcuffs - oh, and a tree with presents.)

# Answer
It isn't a mistake.

Lego weighs the bricks in each bag to ensure that the right components are present. However, it is difficult to weigh the smallest pieces accurately. (This is also why small bits tend to share one bag). If Lego tried to get the component count spot-on there is the danger that they would miss the very rare occasions when one of these small pieces was left out of a box. It would be bad for Lego if there were pieces missing - it would both damage their reputation and lead to expensive support calls. So rather than risk that they intentionally include more of the smallest pieces. That way, if the extra one is missing, nobody minds too much. At the same time, Lego knows that a couple of extra bits will make customers happy, especially as the small pieces are prone to getting lost.

So, you're right to consider the extra pieces as a little bonus.
> 45 votes

# Answer
LEGO sets usually have a number of extra pieces. In most cases they are small bricks, that are easier to lose like 1x1 plates/tiles/studs, cheese slopes, levers/antennas and flower petals.

I know some people would throw the extra bricks away, never do this! Like loose change they will add up over time and can be used to add extra details to your models.
> 15 votes

# Answer
As part of this answer to the question: Does Toy 'R Us (or more expensive-than-average) retailers have more extra parts than average?, user Ambo100 posted a reply from LEGO Customer Services which also has relevance to this question.

> When it comes to spare parts, it is random what pieces are included in which sets. We always want to make sure our fans have a little extra to go with their awesome imaginations.
>
> *LEGO Direct Consumer Services*
> 11 votes

# Answer
One nice thing about the extra parts is that it forces you to think about what you're doing to make sure you did not forget to install one of the small pieces. With larger pieces it's nearly always obvious because things won't fit together properly or look right or be symmetrical.

Tiny pieces can sometimes be forgotten and not affect anything.

Yes, if the count were exact every time you would not have any parts to consider that may have been missed if none were left, but then again if you run short how do you know you didn't put a tiny piece in a place that was not needed and left a tiny piece from where it was needed?

All sorts of scenarios. I think defaulting to extra parts is very wise of Lego to do. It's being very pound-wise and penny-foolish which is the correct way to be.
> 2 votes

# Answer
The answers here from Lego are nice, but the most likely explanation is it's harder to dispense the smaller pieces accurately and so occasionally an extra one falls out. It's better to suffer the loss of one cheap bit of lego than to slow the process down to make it more accurate. And as others have said, Lego knows people will be happy with extra bits but angry with missing ones. So things are left as they are.
> 1 votes

---
Tags: sets
---


# Question
Title: What’s this gold helmet piece and is it rare?
I don’t know what this piece is and where it’s from

# Answer
> 5 votes
That looks like a Minifigure, Headgear Helmet Gladiator

I wouldn't call that piece rare.

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


# Question
Title: What minifigure has a textured lab coat?
With body on legs it will not fully sit down. From a tote of LEGO parts my kids played with in jr high or high school. They graduated in 2008.

# Answer
That's not a piece made by LEGO. It's most likely made by a compatible brand.
> 2 votes

---
Tags: minifigure-identification
---


# Question
Title: Is there any easy, documented or official way to replace pullback mechanism with Motor Set 8293
There are many Technic cars with a pullback mechanism, like 42059, 42073 or 42072.

Is there any systematic, easy, documented or official way to replace the pullback mechanism with the LEGO Technic Power Functions Motor Set 8293?

# Answer
I dont't see how a standard way could exist. That would pretty much require a setup with a PF motor, gears, etc. having the same size and interface as the pullback motor, which according to bricklink (I don't think I have any) is 6x5x3. As far as I remember the only PF motor shorter than 6 studs (there has to be room for at least one gear) is the XL, but that's 5 studs wide.

For any given set, it's quite possible that you could find a solution, and even that the same solution would work for a lot of sets.
> 5 votes

# Answer
It isn't clear what do you mean by "replace with 8293 set". Just with a motor? While there isn't official way (instructions) of doing it I think it is possible to fit the M-motor included in 8293 set with few additional parts. However then there is a question of power. You need to attach battery box somehow. I see this as a bigger issue as there is no convenient place to attach it to.
> 3 votes

---
Tags: technic, power-functions
---


# Question
Title: LEGO Mindstorm EV3 Line-With-Gaps Follower? [Robotc]
Trying to create an algorithm / code in order to get my robot to follow a track which it currently can do, using a color sensor and following the inside edge. So I'm wondering how to transition to the track with broken parts: the track has gaps with a max. length of 20 cm and only on straight parts. I also have a distance sensor available. What would be the recommended ideas?

# Answer
As you already have a working program for the continuous line, you just need to add provisions for the cases when

```
(the robot is moving on a straight part) AND (the color sensor finds a gap in the track)

```

Depending on your existing solution you might need to code dedicated methods to identify the two sub-cases and then call them repeatedly to see if the robot is

* on the track,
* off the track or
* in a gap but on the track.

The above mentioned provision could include just "hold the current direction and continue forwards" or something more elaborate. It could include measuring the distance traveled and seeing if the gap is indeed shorter than 20 cm (and trying to find the line again if a longer gap was found), or introducing a slight fanning motion to help find the end of the gap, or maybe something completely different.

If you post more about your existing solution, we could give you more specific ideas.
> 1 votes

---
Tags: ev3, robotc
---


# Question
Title: Is there a hobbyist standard for Trains track modules?
Many non-LEGO model railroaders have standardized track module standards allowing for interchangeability of (often highly-decorated) track sections (due to availability, damage, scheduling, etc.) as well as quick set up and breakdown of layouts at meetings and conventions. For example, most of the N-scale model railroad clubs in my area adhere to the NTRAK standard. One can make their own custom 4'x2' module at home and "just show up" at a meeting and expect to connect to the organization's layout that day. Similarly, if someone drops the club's Police Station module and damages it, a spare Quarry module that someone happened to have in their trunk can be swapped in as a substitute with only very minor assembly work (mostly plugging things in).

Is there anything resembling a standard module size or configuration among serious or organized LEGO railroad hobbyists?

# Answer
> 7 votes
Yes there is, and the standard is not unique to trains, but rather applicable to all LEGO construction. It is called MILS (Modular Integrated Landscaping System). You can find its specification in many places, but a good resource is at L-Gauge.org, where they have many more resources and standards for the LEGO train hobby.

---
Tags: trains, afol
---


title: Using two color sensors simultaneously

text:
# Question
Title: Using two color sensors simultaneously
I am new to the world of robotics, and I'm preparing a new project with my students. Our goal is to make a self driving robot that can read colored signs from the road in order to turn right or left a specific angle. For example, if the color sensor 1 detects red color, and at the same time the color sensor 2 detects blue color, the robot must turn 90 degrees right. What's the best programming approach to do this? Consider that the total number of combinations could be up to 49 since each color sensor can read 7 colors.

# Answer
There will certainly be some *mechanical* and *robotics* questions that you'll need to figure out, such as where on the car to position the sensors, and how to ensure that the car is reliably reading both colors at every intersection. (Which brings up contextual questions like "are there discrete intersections?")

From a *programming* perspective, 49 possible options is kindof a middle ground.

You could have a systematic representation. For example, each color could map to a digit, and so the pair represents a two digit base-7 number of 2π/49 radians (where 0 means go back the way you came). I don't actually suggest that particular scheme, but something *like* that could work quite well.

You could just have a lookup table. Or a lookup table of lookup tables. In a C-like language that would look something like

```
table = [
  'red':  ['red': -90, 'blue': -45],
  'blue': ['red': +90, 'blue': +45]
];
turn_degree = table[first_color][second_color];

```

I would call that the "normal" approach, although you're getting toward the upper size of the table one might really want.

You could also treat one color as a modifier for the first:

```
first_table = ['red': -90, 'blue': +90];
second_table = ['red': -45, 'blue': +45];
turn_degree = first_table[first_color] + second_table[second_color];

```

This is secretly the same as that first option I gave (base7), but more flexible, easier to read, and easier to explain to kids. And you could use multiplication instead of addition if you wanted.

A robotics consideration: Will the car *always* correctly sense which color is the "first" color?

If not, then there's actually only 28 (21?) possible combinations. You can still use any of the above methods, but additionally you'll define an ordering of the colors (so for example, you'll just decide that green is "less than" blue). Then your "first" color will always be the lesser of the two colors, regardless of which sensor sensed what.

**But seriously, how should you do this in a classroom?**

* If either sensor sees red, the car will turn left.
* If either sensor sees blue, the car will turn right.
* If either sensor sees yellow, the car will turn 15°.
* If either sensor sees green, the car will turn 45°.
* If either sensor sees orange, the car will turn 60°.
* If either sensor sees purple, the car will turn 90°.
* If either sensor sees black, the car will turn 135°.
* If the car doesn't see two colors, or if the colors don't clearly say what to do, then the car just keeps going forward.

```
first = get_sensor_one();
second = get_sensor_two();
directions = ['red': -1, 'blue': 1];
degrees = ['yellow': 15, 'green': 45, 'orange': 60, 'purple': 90, 'black': 135];
if(contains(directions, first)){
  direction_color = first;
  degree_color = second;
} else {
  direction_color = second;
  degree_color = first;
}
if(!contains(directions, direction_color) || !contains(degrees, degree_color)){
  keep_going();
} else {
  turn(degrees[degree_color] * direction[direction_color]);
}

```
> 2 votes

---
Tags: ev3, programming, sensor-colour
---


# Question
Title: Best Way To Make This 8x8 Grate Plate Flush With The Wall?
I would like to use the 8x8 grates on the side of the building (studs out) as window pieces so there is nothing behind them. I'm wondering if there is a better way to have a more stable connection. I'm kinda stumped if I can pull this look off. Of note and not easily seen in the picture: There are four panels used in this section.

# Answer
JMK!

This is what I came up with:

* Studless overall look.

* Studless (Gray) window paneling and thickening.

* Bird's eye view.

---

*LEGO Digital Draw* build file: ***HERE***.
> 4 votes

# Answer
This was not as easy as I thought. I think I solved the "flush" problem in the following way:

This is the final result:

The secret behind it consists of brackets 2436 (or 2436b) and the famous hinge plates 4275 / 4276.

For the lower part, put the brackets on top of two plate layers. Then add a 1x8 plate in front.

For the upper part, you need the brackets upside-down. To do this, put together the hinge plates upside-down as shown and attach the brackets. Then add a 1x8 plate in front. Now you can attach the 8x8 plate, and it will sit firmly and - most importantly - flush with the front wall.

In the end, you can cover the frame with whatever you want.

I hope, this works for you. The most difficult part was to figure out that the upper brackets need to be upside-down.

I just noticed that you need this on all 4 sides of the tower. In this case, you can use only one bracket/hinge combination on each upper side (e.g. only on the right of each 8x8 grate).
> 2 votes

---
Tags: building
---


# Question
Title: Two motors are driven forward, why are they rotating in different directions?
I have the Lego Mindstorms EV3 Pack and built a simple car with 3 wheels. The back wheels are motorized.

When I run the following code:

```
Motor.A.backward();
Motor.D.Backward();

```

both motors are rotating in **different** directions. I could understand if backward needs to be interpreted as forward. But how come that the motors are behaving differently?

It is basically not a big drama, I could build a wrapper to handle this. But still: When I want to use a chassis implementation, I would maybe run into that problem?

# Answer
> 3 votes
The "forward" and "backward" expressions are only interpreted in the reference frames of the motors themselves and translate to clockwise and counter-clockwise. In your case you must have mounted the motors in a way which requires them to rotate in different directions in order to propel the vehicle.

Consider a car with four wheels: in order to go forward, the wheels on the left hand side need to rotate counter-clockwise but those on the right side must turn clockwise.

While most chassis types share this property, it is indeed possible to build a chassis that requires both motors to be driven in the same direction for the vehicle to advance. In that case the program must be adjusted to accommodate for that.

---
Tags: ev3, mindstorms, motor, lejos
---


title: Who are these Figures?

text:
# Question
Title: Who are these Figures?
Does anyone recognise the two larger LEGO figures? They are from sets released in the 80’s and I am trying to find out what sets they’re from so I can hopefully build the sets with my son. One is a fireman and came with a fire engine. They fit perfectly between Duplo and LEGO but I can’t seem to find any trace of them, the closest similar product I’ve found is Fabuland which is all animals but the same size figures.

# Answer
These are Basic Figures

and \- fab13c : Basic Figure Human, Black Legs, White Hat

from 392-2: Fire Engine
> 8 votes

---
Tags: minifigure-identification
---


# Question
Title: Helmet with flip-down binoculars is not in any of the databases
The helmet has 10198 inside but I cannot find that on any of the usual part databases. Does anyone have any ideas?

# Answer
It's probably a 3rd-party LEGO-compatible accessory, several 3rd-parties make such military themed accessories.

LEGO doesn't make very many modern-day military-themed pieces and I found similar pieces on one 3rd-party accessory shop. It's not an exact match, but it's pretty close. It might be that you have an older version of their product, or some competitor's product.
> 4 votes

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


title: Color sensor reliable?

text:
# Question
Title: Color sensor reliable?
I am experimenting with the light sensor shipped within the mindstorms ev3 package.

My Problem is that the bot is standing quiet at one place. Each value returned by sensor is different, although the bot is not moving. Why? :-(

I am using the Red mode:

```
SensorMode t = sensor.getRedMode();

float[] sample = new float[1];
t.fetchSample(sample,0);
return sample [0];

```

I tried putting the sensor in different positions and tried different distances to the floor. When it is on a black line the values differ a lot.

Which sensor modes do you guys use for getting reliable information about underground colour? Or let's say underground brightness?

# Answer
Light sensors are mainly affected by three independent variables:

* Distance between the sensor and the surface
* Color of the surface
* Amount of ambient light

What this means is, in order to measure one of these things, the other two variables must be held constant. So, in order to measure color, the distance must be constant and the ambient light should be constant.

You can maintain a constant distance between the sensor and the floor by attaching the sensor, pointing downward, to a fixed point on the robot. Simple enough. In my experience the sensor should be about 1cm from the floor for best results.

You can maintain a constant ambient light by avoiding shadows or bright lights. If this isn't possible, you can build a shroud over the sensor to block out external light. You should also recalibrate the sensor at program startup to account for ambient light.

After doing the previous two things, you can measure the reflected light from the surface by shining one of the colored LEDs and taking a sample. Using only 1 LED should be sufficient to detect differences in grayscale, but to actually measure "color" you can quickly cycle between the Red, Green, and Blue LEDs, taking samples with each, to get a crude estimate of the RGB components of the surface.
> 2 votes

# Answer
I solved my problem:

I was experimenting with the sensor and its modes and I came up with following solution:

I am using the RGB mode and read the three samples. The samples are much too accurate, so I round them at the second place after decimal delimiter and use the red value only.

In this way I can place my robot on the paper and each time I get the same value for white or black (light or dark).

I also assembled a kind of light protection around my sensor, but this allone did not result in same values on white places.

I was now able to implement a line follower which works with intervals for light, neutral and dark zone, each one in a seperate behavior.
> 0 votes

---
Tags: ev3, mindstorms, sensor-colour
---


# Question
Title: Can't link variable inside a switch when creating a new block
I have a problem when connecting the variable (from the create a block) to a variable in the function because it's inside a switch. How can I link them?

I want to connect the variable to each (20) in the motor blocks

# Answer
Using variables is probably a better solution, but you can pass data wires into a switch block if it is tabbed view.
> 2 votes

# Answer
To get technical, this thing (pictured below) is a "parameter", not a "variable".

"Variables" look like this:

You can use a data wire to write the parameter value to a variable *before* the switch block and then read the variable inside of the nested switch blocks. Something like this...
> 1 votes

---
Tags: ev3, programming, motor
---


# Question
Title: What is a good third party battery box and receiver?
I got the LEGO 4x4 crawler for my birthday and I love it. But there is one slight thing which I hate: it has terrible range when using it outside. I know there is BuWizz which is a third party receiver but it can only be used with a phone. So I can’t use that, because the whole reason why I got the 4x4 crawler was to get me off of my iPad. Does anyone know a 3rd party remote, receiver or battery box?

I’m 12 and unable to do any electronic modifications, like using tools and modifying electric components.

# Answer
> 4 votes
As you have mentioned, there is BuWizz and SBrick which, while primarily are intended to work with smartphones, are said to be able to work with joysticks or gamepads, albeit possibly with bugs.

I don't really see why would your age mean that you can't do modding, but assuming you have budget restrains or parents who would not allow it then these are valid reasons. Anyways, I'm sure you have your own reasons, just don't underestimate your abilities just because of your age.

There is of course the new Powered Up system from Lego, on the right side of this image you'll see the controller and the motors currently in use:  Drawback: There are no servo motors available for it yet, so you can't fully control the 4x4 crawler without extensive modifications to either

* use a second motor for steering or
* settle for a tank-style drive with a separate channel and motor for the left and right wheels.

Another third party solution I have managed to find is the CADA controller. The main selling point is exactly what you are asking for:

> The most interesting feature is indeed dedicated controller, unlike buwizz/sbrick there is no need for smart phone.

According to one reviewer:

> The range is limited to 10-12 meters

so it should yield better results as the PF infrared remote.

# Answer
> 3 votes
The original question asked about complete turnkey systems, without "any electronic modifications, like using tools and modifying electric components", for which the other answer provides solutions. This is the answer for all other possibilities, as prompted by Aziraphale:

> It might be that third party producers provide remote controls ready for implementation in LEGO sets. We see the same for lighting systems that contain LEDs, batteries, ultra-thin wires etc. I would also accept non-professional custom solutions that allow usage of non-LEGO parts in my sets, possibly by showing how to glue/connect non-LEGO equipment to LEGO bricks.

**Disclaimer**: I have neither authored, nor tested any of these ideas, but I have reviewed them all and deemed them useful and correct. The information contained them might nonetheless be incorrect, outdated or unusable for any other reasons.

The simplest option would be to extend the range of the existing receiver by increasing the power emitted by the IR remote control, by using a custom IR transmitter:

A fully LEGO compatible DIY electronics project is authored by w4ilun and uses a Toshiba motor controller embedded in a custom-designed printed circuit board to interface with cut and repurposed PF cables:

If we are willing to forego LEGO Power Function motors as well, we can use any kind of DC motor we can build a LEGO compatible enclosure for. This project uses the radio control parts salvaged from a toy car to integrate them into a LEGO chassis:

Or an existing 2.4 GHz remote can be used with this custom designed receiver:

---
Tags: technic, power-functions, electronics
---


# Question
Title: Which part number goes to these LEGO wedge pieces?
I'm trying to identify these two parts, plus the color on the greenish one.

# Answer
> 9 votes
The white one appears in 51 sets. It is piece #43713 "White Wedge 6 x 4 Triple Inverted Curved".

The second piece looks like its color is "sand green", which is color #151. It is part #47759 "Wedge 2 x 4 Triple", which appears in one set in sand green: 70840 "Welcome to Apocalypseburg!"

# Answer
> 0 votes
I got it; it's actually LEGO Olive Green Wedge 2 x 4 Triple (47759).

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


title: Bionicle parts for own bionicle figure

text:
# Question
Title: Bionicle parts for own bionicle figure
I need Bionicle parts to make my own Bionicle. Any good set recommendations? Any LEGO set will do. It does not have to be Bionicle.

# Answer
> 1 votes
There aren't many sets with big Bionicle part variety. I'm not sure what you are looking for. If you need specific parts I suggest to look for them on Bricklink. If you need to increase your Bionicle parts collection it might be better to look for local sales as Bionicle/Hero Factory are usually quite cheap.

---
Tags: bionicle, pick-a-brick
---


# Question
Title: Do they have every brick type or just the basics at the PaB wall?
I am looking for a specific piece and I don’t know if they will have it. Is it any piece or just basic ones like 2x4’s?

# Answer
At the LEGOLAND California Pick a Brick wall last week (March 9th 2019) they had mostly basic brick shapes. There were some plates, some modified bricks with studs on the side, and a couple of containers had thick rubber wheels, the smallest kind. There was also a container of 1x6x6 panels in white. Nothing else stood out as particularly interesting.
> 1 votes

# Answer
Can you imagine the size of PAB wall to contain every piece? It would be enormous. So naturally PAB brick choice is limited.

Normally shop management decide which bricks they are willing to have on their wall. However there are exceptions:

* some stores have space dedicated to PAM (pick-a-model), with all parts available for such model;
* some stores may have "AFOL choice" bricks;
* there may be shops testing some new bricks choice.

And so on. So chances you find a piece you need are random. If you look for a particular piece - give a call to accessible LEGO stores with PAB or order them online via LEGO webpage or Bricklink.
> 1 votes

# Answer
The management (or the employee(s) they have delegated that to) of each store decides what is in the wall of that store, but they do it from a list of elements somebody higher up, thinks should be in the stores (and having been to a number of stores, I guess it's the same list. at least on each side of the Atlantic ocean).

There's always a selection of fairly standard element It probably don't accurately reflect what's in that wall today, but they can give an idea of what the s, but always also a selection of not so standard elements.

There a website dedicated to listing what's in the wall at each store, but it's only correct if somebody updates it, and as we don't use that in Copenhagen (see below), I've forgotten the address.

In Copenhagen traditionally nobody can be bothered updating that site, but there are a few members of the danish LUG that takes an element from each hole, places them sort of nicely on a table and takes some pictures, that they then share. An old (january 2017, I couldn't find a recent, and this is just to give an idea anyway) set of such pictures: https://www.flickr.com/photos/25179966@N06/sets/72157668755923501
> 0 votes

# Answer
When going on a toy run to any store, the easiest thing to do is to simply call the place up, and speak to a live person. In most cases they want to help you not waste your time or money on a fruitless trek.

The store could be a *Target*, *Walgreens*, *GameStop*, *Best Buy*, *Barnes & Noble*, *Sears*, *Walmart*, or *LEGO* Store. Just *Google Map* the area for a specific store and a list of locations and phone numbers pop up.

Simple say "Hello, or Hey there", and repeat the franchise name, "I'm looking for..."

Either way, if they say they do or don't have it, use this time you have them on the phone to chat them up about new promotions, "Hey *LEGO* store, I haven't been in there in a month or two, has anything changed?"

So, personally I'm 40 minutes between two stores, but haven't been to one since past November. The last thing my *LEGO* rep said to me that might help in regard to your specific question about needing a specific piece is, *LEGO* allowing a store to order their own inventory, which is something great.

It might take a little more patience, and fitness with other store reps that aren't versed in *LEGO*, but always remember the gas money saved by not driving there on a hope and a prayer.
> 0 votes

# Answer
Check the inventory at your local store (and please update it if it's out of date!) http://www.brickbuildr.com/index.php/all-stores/
> 0 votes

---
Tags: shopping, pick-a-brick
---


# Question
Title: Why does the Gyro Sensor not work correctly in Virtual Robotics Toolkit?
I somehow found out about Virtual Robotics Toolkit and when I did, I decided that it would be great software to use for Lego League. Later in my research, I found that it automatically had the newest tables.

Soon I was designing a robot and code for my team, but as soon as I tested it the virtual robot started driving off to one side. Even though it was doing this, the EV3 software said that it was at 0°. When I tested the same program in real life, the robot drove perfectly straight.

You can download the source code here. (ORBIT3R-BOT.ev3)
You can download the robot model here. (ORBIT3R-BOT.lxf)
You can download the robot model here. (ORBIT3R-BOT.ldr)
You can download the VRT project here. (IntoOrbit)
You can download all the above (and more) here. (Robot)

# Answer
Try to reset angle on the gyro sensor. Click on the block and choose reset.
> -1 votes

---
Tags: ev3, software
---


# Question
Title: Is it possible to build 3 or more concentric circles / nested circles / telescoping pieces?
There are round 2x2 pieces. There are round 4x4 pieces with round 2x2 holes, the 2x2 can slide/rotate inside of it. There are "macaroni" pieces to make an 8x8 circle with a 6x6 hole. But are there no 6x6 rounds with a 4x4 hole?

I've also seen sets use curved slopes, curved inverted slopes, and arches to make circles or nearly-perfect-circles. Are there ways to make nested circles from those pieces?

# Answer
There is only one piece that fits all your criteria: 41823. Placing four of those pieces together will create a 6x6 circle with a 4x4 interior gap. Albeit, it is a decorative fence piece and it's two studs tall, so it might not work for what you are trying to accomplish.
> 3 votes

---
Tags: building, compatibility, design
---


# Question
Title: Anyone have the control block for the hitechnic color sensors?
I'm just wondering if anyone has a copy of the control block for the hitechnic color sensor v2? I'll take a v1 if you have that because I'm desperate at this point. The downloads page for it is down and my team needs this soon. If you have this or know where it can be found please can you provide the link?

# Answer
> 5 votes
It looks like the page listing downloads is down, but direct links to the downloads still work. I believe that this is the file that you're looking for:

https://www.hitechnic.com/upload/306-Color%20Sensor%20V2.zip

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


# Question
Title: How to include submodel into main model in LeoCAD?
In LeoCAD I can create multiple submodels. But how do I merge them or integrate one into the other? The release notes suggest that this is possible, but I can't seem to find out or find resources about how to do it.

The idea behind this is that I would like to create building instructions for the model using LPub3D. I would like to use submodels to make the building instructions easier to understand. I would like to show how a certain part of the model is built and then at some point integrate it into the main model. So far I have not managed to do this. The different submodels coexist separately and in LPub3D I have only access to the main model (i.e. the first submodel).

# Answer
I have now figured out that you can include submodels the same way as normal parts. In LeoCAD, go to the parts panel where you can select a category ("All Parts", "Parts in Use", ...), scroll to the very bottom and select "Models". Then you can select your submodels and incorporate them.

(For some reason, my submodels still don't show properly in LPub3D, but I guess that is a separate question.)
> 3 votes

---
Tags: software, instructions, cad, ldraw
---


# Question
Title: Submodel does not show properly in LPub3D
I am new to digital LEGO models and building instructions with LPub3D. In order to find my way around submodels I have created this very simple dummy ldraw model:

```
0 FILE new model.ldr
0 Name: new model.ldr
0 Author: Undefined
1 4 10 -24 -90 1 0 0 0 1 0 0 0 1 3005.dat
1 4 10 -24 10 1 0 0 0 1 0 0 0 1 3005.dat
1 4 110 -24 -90 1 0 0 0 1 0 0 0 1 3005.dat
1 4 110 -24 10 1 0 0 0 1 0 0 0 1 3005.dat
0 STEP
1 4 60 -32 -90 1 0 0 0 1 0 0 0 1 3666.dat
1 4 60 -32 10 1 0 0 0 1 0 0 0 1 3666.dat
0 STEP
1 1 0 0 0 1 0 0 0 1 0 0 0 1 roof.ldr
0 NOFILE
0 FILE roof.ldr
0 Name: roof.ldr
0 Author: Undefined
1 1 10 -56 -90 1 0 0 0 1 0 0 0 1 3005.dat
1 1 10 -56 10 1 0 0 0 1 0 0 0 1 3005.dat
0 STEP
1 1 10 -64 -40 -0 0 -1 0 1 0 1 0 -0 3666.dat
0 Name: roof.ldr
0 Author: Undefined
0 NOFILE

```

It adds some red bricks in two steps and then references a submodel that itself consists of two building steps, too, adding some blue bricks. The file shows alright in LeoCAD, but when I open it in LPub3D it shows the expected building instructions for step 1 and 2, followed by the two steps of the submodel. But then when it should show the result of merging the submodel into the main model it only shows one blue box at some weird place instead of the submodel. Does anyone know what I am doing wrong?

# Answer
It looks like I might not be doing anything wrong after all. If I switch the preferred renderer from native to LDView under Preferences everything looks fine.

Maybe I should mention that I am using LPub3D 2.3.6 under Linux. At least the Linux version seems to be rather buggy. It regularly crashes with a segmentation fault when you try to edit the configuration. So this behavior might be a bug, too.
> 1 votes

---
Tags: software, instructions, cad, ldraw
---


# Question
Title: Can the experts Identify these sets, grey octagon platform and tan plates?
A friend gave us a bunch of sets with only a few sets of instructions. We were able to figure out a few of them. Not sure what these are.

# Answer
Mostly, both pictures come from *Set #79006 The Council of Elrond*, but...

...Minifigure white chest piece comes from: *Set Col03-15 Rapper, Series 3 (Complete Set with Stand and Accessories)*.
> 5 votes

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


# Question
Title: Can you identify this 1x2 brick with groves going opposite directions on each side?
There are about 20 of these bricks in the set. Nothing else that stands out as unique. This may be a long shot.

# Answer
*Part #2877 Brick, Modified 1 x 2 with Grille (Flutes).*
> 6 votes

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


# Question
Title: Seeking HiTechnic Color Sensor V2 control block for EV3-G
I'm looking for the EV3-G control block for the HiTechnic Color Sensor V2, previously distributed by HiTechnic (https://www.hitechnic.com/cgi-bin/commerce.cgi?key=NCO1038&preadd=action), apparently now distributed by Modern Robotics (https://modernroboticsinc.com/product/hitechnic-nxt-color-sensor-v2/).

Many websites and online installation guides claim that the block is available from the downloads and support website from the original supplier (https://www.hitechnic.com/downloadnew.php?category=38). However, that site has been down for at least the past week and perhaps longer. Emails to both HiTechnic and Modern Robotics have gone unanswered, thus it appears that the sites are no longer maintained. :-(

A similar question was recently asked and answered (Anyone have the control block for the hitechnic color sensors?), however, the direct download link suggested there (https://www.hitechnic.com/upload/306-Color%20Sensor%20V2.zip) is for the older NXT control block only. Unfortunately, the NXT block is not compatible with EV3-G and the current EV3 brick. I'm seeking the EV3 block, not the NXT block.

I hope that someone here can help.

# Answer
Hitechnic.com now points to modernroboticsinc.com. You can find the Hitechnic EV3 color sensor block here:

https://modernroboticsinc.com/download/hitechnic-ev3-color-sensor-block/

All available downloads are available and searchable here:

https://modernroboticsinc.com/downloads/
> 2 votes

# Answer
Thank you! The answer from jncraton did the trick.

Summary: the direct download for the EV3 sensor block for the HiTechnic Color Sensor V2 is here: https://www.hitechnic.com/upload/545-HiTechnicEV3Color.zip

The zip archive includes three files: (1) instructions (HTColorREADME.txt) (2) the control block (HTColor.ev3b) (3) a sample file demonstrating use of the control block (ViewColor.ev3) All three worked like a charm.

The instructions above for locating arbitrary HiTechnic files worked well also. This technique will be useful to others seeking programming blocks for other HiTechnic sensors.
> 1 votes

---
Tags: ev3, ev3-g, sensor-colour
---


# Question
Title: My DUPLO railroad engine stops after 20cm
My DUPLO railroad engine stops after 20cm moving. I suppose the sensor in the front axle is damaged.

So is it possible to repair it?

# Answer
> 1 votes
If you have red floor or carpet, that could be recognized as the Stop Rail Accessory by the engine. Otherwise I would contact Lego customer support.

---
Tags: trains, duplo, repair, electronics
---


title: What does the acronym SPUA stand for?

text:
# Question
Title: What does the acronym SPUA stand for?
I once heard someone use the acronym SPUA while referring to a LEGO piece. What does that stand for and what does it mean?

# Answer
> 8 votes
SPUA - Special Part Used Again, a part which is seemingly only for a particular set or theme, but is used again

List of LEGO Abbreviations from Brickipeda

---
Tags: terminology
---


# Question
Title: Mystery 2x14 grey brick - cannot find instructions with this piece mentioned
I have a bunch of LEGO bricks from the years 1975 - 2016. There are a lot of obscure pieces in my collection, but this piece is so obscure that I have no idea what it goes to. If anyone can help it would be much appreciated.

# Answer
This is **item no 812**

* Train Level Crossing Center Rail Cap Insert 2 x 14 x 2/3

made for item no 813, the railroad crossing.

(source: bricklink)

It replaces the 12V straight insert (i.e. it closes the middle gap) when using a 4.5V train system.
> 12 votes

---
Tags: part-identification
---


# Question
Title: How can I separate an 8H antenna from a modified 1×1 with ring?
I have two parts which are stuck together:

* 4081b: Plate, modified 1×1 with clip light – thick ring
* 2569/25699/47094: Antenna whip 8H

The parts have been assembled like this for about 20 years and may have dust in between them. They have been cleaned with water and mild hand soap. They were stuck firmly before cleaning. Other instances of the same assembly were not so difficult to take apart.

I have tried gripping the antenna and pushing it through, prying my fingernail against the lip where the antenna gets thicker near the base, and prying between the base and the ring with fingernails. I've also tried flicking the tip of the antenna to try to knock it loose and twisting while holding the shaft, but it's really in there. Before I try prying with stronger tools that could gouge the parts, I wonder if anyone has any tricks for separating these parts.

# Answer
Ah, yes. I have had this problem a few times. Here's what I do:

1. The first thing you're going to want is *leverage*. Connect one 1x6 plate to the underside of the Modified 1x1, one on top of the previous plate (but adjacent to the Modified 1x1), and one on top of both pieces.
2. Next, slide propeller piece 32125 over the tip of the antenna.
3. Hold the antenna upside-down (vertically), with the 1x6 assembly in your right hand. Move the propeller piece all the way up, but stop before it gets to the section the Modified 1x1 is on. Maneuver the antenna's stem into one of the four sides of the axle hole on the propeller piece, tilt it at an angle, and push up. There should be a slight pop and the 1x1 will move down the antenna.
4. Now that you have something to push on, simply remove the propeller, grab hold of the 1x6's with your right hand, and press into the base of the antenna with the propeller piece. It should pop out the rest of the way and then you're done!  **Why does this work?** Well, the propeller piece is *perfect* because it had a proper diameter to fit over the round tip, and the sides of the axle hole are a prefect dimension to hold the smaller thickness of the antenna stem, thus giving you a contact point for applying pressure. I suppose it's a bit over complicated, but it works for me. :)
> 9 votes

# Answer
*I fail to reproduce your problem. When I combine these parts, they are easily separable. Hence the following is an educated guess:*

1. Put the antenna on a big plate on a table (for stabilisation).
2. Grab the antenna slightly above the clip with one hand and hold it tight.
3. Grab the clip with the other hand and push up, while turning it around the antenna’s axis.
4. If needed, use the rest of your hands to push down the plate for further stabilisation.
> 4 votes

# Answer
For completeness, I am posting the solution which ultimately worked for me. It is just Wrzlprmft's answer with extra parts to keep the 1x1 in place. It is also very similar to Magnus's answer, but without the propeller.

I surrounded the 1x1 with blocks on all sides so that it could not rotate or come off easily. Then I firmly gripped the antenna as close to the base as I could and pushed it through.
> 3 votes

---
Tags: disassembly
---


# Question
Title: Can two Powered Up train motors be plugged into one hub
I have set #60198 and it comes with one Powered Up motor. I'm hauling many many cars and one motor isn't enough any more. I see there is a slot for "B" on the hub. Is it possible to plug in another train motor into B and have the train be powered by 2 motors?

Does it even help? Not sure if a second motor would just split the power between the two motors if it worked, or does it draw 2x the battery from the hub?

# Answer
You can attach second train motor to B output. However it will be controlled independently from motor attached to output A. So you would need to control speed for each motor separately.

Speaking of traction. The key thing here is your train weight. You might consider putting another full battery box (unpowered) into train just to increase weight and get more friction between wheels and the track.
> 2 votes

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


# Question
Title: How can I separate 1 x 1 round from boat mast base 4 x 4?
I have two pieces I cannot seem to separate. The parts in question are:

* 3062b: Brick, Round 1 x 1 Open Stud
* 6067: Black Boat Mast Section Base 4 x 4 x 1 2/3

The 1 x 1 is transparent in this case, in case that makes a difference (I think the plastic type is different for transparent pieces).

The center of the mast base fits snuggly inside the 1 x 1. The outer wall of the mast base blocks access to the bottom lip of the 1 x 1. There is a hole through the bottom of the mast base, but it's narrow enough that if I try to stick a 3957 antenna through it, the tip of the antenna doesn't catch the top lip on the inside of the 1 x 1 round. I tried pinching the top of the 1 x 1 and wiggling it, but it is too tight.

Separate:

Assembled:

# Answer
> 6 votes
How about a straightened paperclip pushed through the hole in the mast from the bottom? You could put a small piece of paper in first so that it'll catch on the 1x1 on the way out.

---
Tags: disassembly
---


# Question
Title: Are the LEGO Friends Mini-dolls compatible with Minifigures?
I've seen the new LEGO Friends sets, and wanted to know if the Mini-dolls are compatible in any way with minifigs?

I'd quite like to get some sets for the new colours however I want to ensure the accessories, etc. in the set aren't going to be out of scale.

# Answer
In some ways but not others, according to this post by Catsy at The Brothers Brick:

> * It was near-impossible to pull the legs off–I sawed through them where they join above the knees.
> * The tab that connects the waist to the torso is completely incompatible with any standard System connection I’ve tried.
> * The hands are not angled forward the way a minifig’s are–so accessories with a pronounced rake to them may not look as expected.
> * The lack of wrist articulation is extremely limiting in terms of how you can pose them with accessories.
> * The stud connection point on the feet is in the front, under the doll’s center of gravity and more or less directly under the body. The feet are slightly oblong.
> * The legs have a very slight backward sweep on the way down, which you can see most clearly on the right leg above. The upshot of this is that it is impossible for a mini-doll to stand on any 1×2 area that has anything immediately behind them.
> * The neck is a standard 3mm bar connection rather than stud-width like a minifig neck–the heads are incompatible with minifig torsos.
> * The head is approximately the same dimensions at the top as a minifig head, but tapers towards the chin in a roughly egg-like way.
> * The nose causes complications with some fully-enclosed headwear, but not most. The chin extends lower than a minifig’s chin, so that headwear with “chin straps” obscures the mouth.
> * The hair is interchangeable with minifigs–and many TLC minifig hairpieces look quite good on the girls... it is made out of the same kind of soft plastic as the Exo-Force hair, and has tiny holes on the top and side of the hairpiece that go all the way through, allowing the attachment of hair accessories.
> * Brickarms helmets work extremely well and look great. I do NOT recommend trying to use aftermarket hairpieces, however–I tried putting a third-party hairpiece on one of them and had to use pliers to get the head back out.

Note also that the legs do not move independently of each other - both left and right legs are on the same hinge. Not really a compatibility issue, but it greatly restricts the poses available without modification.

From the official press pack:
> 19 votes

# Answer
The other answers speak well about *technical* compatibility. With the release of *The LEGO Movie 2* film and its associated LEGO sets, we have official confirmation that Minifigs and Minidolls are supposed to be able to exist and interact in the same universe. For example, see set 70830, *Sweet Mayhem's Systar Starship*:

We see a Minidoll Sweet Mayhem alongside Minifigs of Lucy and Emmet.
> 4 votes

# Answer
It is mentioned in the previous answer that the feet are slightly oblong. I snapped a few photos to illustrate how this impacts the level of compatibility between the two figure types.

A standard minifigure will easily be able to 'stand' within a 1 x 2 space. In most cases, this applies to a 'Friend' as well, unless the 1 x 2 space is recessed. The oblong feet make it impossible for the 'Friend' to be used in this way.
> 3 votes

---
Tags: minifigures, compatibility, friends
---


# Question
Title: What is the biggest base plate available?
I'm looking for as large a base plate as possible. Below is a 48x48 stud base, it's the largest I've seen.

Are larger plates available? Either the thin type (as pictured) or the regular plate thickness will do!

# Answer
The largest baseplate (thin kind) is 50x50 studs: http://alpha.bricklink.com/pages/clone/catalogitem.page?P=4186a#T=P

The largest regular plate is 16x16 studs only: http://alpha.bricklink.com/pages/clone/catalogitem.page?P=91405#T=P
> 8 votes

# Answer
The largest official baseplate that I'm aware of is 50x50 modules.

It's only slightly larger than a 48x48, and it's a bit more difficult to use in large setups since most other common baseplates have side lengths that are a multiple of 16, so you might actually be better off with a 48x48 depending on what you are trying to do.

This part hasn't been available since the 70s, but you can still pick it up on Bricklink.

You may be interested in this answer which includes other raised baseplates:

What is the largest single LEGO piece?
> 10 votes

# Answer
There is a 48 by 64 Lego-compatible baseplate available.
> 0 votes

---
Tags: piece-information
---


# Question
Title: What is a color sensor and where do you get it?
I have an NXT but I don’t know how to make it detect colors, all it does is say “wait”. My set includes a light sensor but I heard some YouTube videos say there was a lego “color” sensor. Does LEGO sell this? Can some one tell me how to get it please?

# Answer
Lego has made colour sensors for various robotics themes, including Boost, EV3, and NXT. NXT is pretty old so you'll need to head to a 3rd party website like Bricklink to buy one.
> 1 votes

# Answer
The Original Mindstorms NXT only came with the NXT Light Sensor. The NXT Light Sensor *cannot* detect colors, so this is most likely what you have. You can currently purchase the NXT Color Sensor from Bricklink.com for under $30.
> 4 votes

---
Tags: mindstorms, sensor-colour
---


# Question
Title: Has the building technique of Technic pins in a brick cylinder been used in an official set?
One of my favorite building techniques is to place a Technic pin into the anti-studs of a brick. This allows two bricks to attach bottom-to-bottom.

It's a pretty secure connection, but I'm not sure it was intended to be used this way. **Has this building technique ever been used in an official LEGO set?**

# Answer
I'm not aware of this being used in any official sets, but I'm happy to be proven wrong. I can say that LEGO considers this to be an "illegal" connection. The Technic pins need room to spring back out and be "in click", or they can be permanently damaged by prolonged assembly. LEGO would not allow this connection to be used in a current set.

A Technic pin not "in click" was used back in 2002 in the Audi TT and led to part damage as well as this sort of connection being banned from sets:
> 11 votes

# Answer
No, LEGO did not intend to do that building method though I have to admit, It is a pretty cool technique. So far there haven’t been any sets like that but maybe in the future LEGO people will realize they can do that.
> 1 votes

---
Tags: technic, building
---


# Question
Title: How can I assemble 2 opposing gears so that the axle rotations are perfectly parallel?
Due to the way all the modern LEGO gears are perfectly quarter-turn symmetrical, there doesn't appear to be any way to assembly 2 opposing gears such that I get a 2 perfectly parallel axles.

This image illustrates the problem:

When one gear it perfectly centered, the other gear is rotated half a tooth.

How can I get 2 opposing gear's axles to be perfectly parallel? Are there any older or special gears that are useful here? Otherwise, are there any good workarounds?

# Answer
> How can I get 2 opposing gear's axles to be perfectly parallel? Are there any good workarounds?

You could use an **idler gear**. It will even out the offset.

Yet, at the same time, it (or any odd number of idler gears) will cause both axles to spin in one direction.

On the other hand, two (or any even number of) idler gears will not affect the asynchrony of the axles, but will bring back the offset.

Then again, **placing a single idler gear crosswise** will compensate the offset without changing the desired clockwise/ counterclockwise movement.

Besides, here's two 8 tooth idler gears in line. Both axles seem to be perfectly in parallel to each other.

Unfortunately, that's actually because of the large amount of play involved. So this solution just benefits from the wiggle and does not run too reliably.

Edit:

> Are there any older or special gears that are useful here?

At least theoretically.

Having an uneven number of teeth, these nowadays obsolete gears from the early 70s would work as well.

As you can tell from the overlapping grey gears, the axles are quite parallel (minus some backlash).
> 9 votes

# Answer
If you use a crown gear or bevel gear to connect your gears twice perpendicularly, they are exactly opposing each other, turn in opposite directions, and are parallel (if the respective axle is aligned to the coordinate system of the construction). Like with all gear-to-gear connections, you have a little wiggle room that may exceed half a tooth.

If you want the opposing gears next to each other, you can use further gears attached to these (coming with yet more wiggle room).
> 7 votes

# Answer
You could use a belt system to get a perfect, parallel rotation. The chain links used in this video are #3711 and the gears appear to be the same as the ones shown in your example.

There doesn't seem to be an easy way to get the gears to turn in opposite directions without the use of gears (without that half tooth lag).

Two high friction, Technic rubber wheels, placed directly against each other will rotate almost perfectly. Although they might de-synchronise after many revolutions.
> 4 votes

# Answer
What about a clutch gear ? It can help with its center axis that can slip.
> 1 votes

---
Tags: technic, building, gears
---


title: Identify this fire truck set?

text:
# Question
Title: Identify this fire truck set?
Can anyone identify this fire truck set? I’d like to find the instructions before it gets taken apart.

# Answer
> 10 votes
# 6752-1: Fire Rescue

Instructions:

---
Tags: set-identification
---


# Question
Title: Looking for custom EV3 block to control LEDs independently
The EV3 brick has 2 LED sets, one on the left side of the button panel and one on the right.

Software such as python for ev3dev let's you control them both individually, the normal EV3-G LED block however only allows to set them both to the same value.

Has anybody created a custom block that I can import into EV3-G that allows me to control the left and right LEDs individually?

# Answer
It is not possible to control the LEDs separately using the official EV3 firmware. You would have to modify the kernel drivers. You can only use the predefined patterns shown here.

```
ULONG     LEDPATTERNDATA[NO_OF_LEDS + 1][LEDPATTERNS] =
{ //  LED_BLACK   LED_GREEN   LED_RED    LED_ORANGE           LED_GREEN_FLASH                     LED_RED_FLASH                     LED_ORANGE_FLASH                      LED_GREEN_PULSE                       LED_RED_PULSE                      LED_ORANGE_PULSE
  {  0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0b00000000000000000000000000000000, 0b00000000000000000111110000011111, 0b00000000000000000111110000011111, 0b00000000000000000000000000000000, 0b00000000000000000000000001110111, 0b00000000000000000000000001110111 }, // RR
  {  0x00000000, 0xFFFFFFFF, 0x00000000, 0xFFFFFFFF, 0b00000000000000000111110000011111, 0b00000000000000000000000000000000, 0b00000000000000000111110000011111, 0b00000000000000000000000001110111, 0b00000000000000000000000000000000, 0b00000000000000000000000001110111 }, // RG
  {  0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0b00000000000000000000000000000000, 0b00000000000000000111110000011111, 0b00000000000000000111110000011111, 0b00000000000000000000000000000000, 0b00000000000000000000000001110111, 0b00000000000000000000000001110111 }, // LR
  {  0x00000000, 0xFFFFFFFF, 0x00000000, 0xFFFFFFFF, 0b00000000000000000111110000011111, 0b00000000000000000000000000000000, 0b00000000000000000111110000011111, 0b00000000000000000000000001110111, 0b00000000000000000000000000000000, 0b00000000000000000000000001110111 }, // LG
  { 0 }
};

```
> 3 votes

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


title: What is this part?

text:
# Question
Title: What is this part?
I found about a dozen of these in a mixed bunch of LEGO. Are they actual LEGO pieces or another brand? They are actually white, the pink color is a lighting error.

# Answer
> 3 votes
This is part 42446 or 28974; Minifigure, Neck Bracket with Back Stud.

---
Tags: part-identification
---


title: Selling completed and assembled models?

text:
# Question
Title: Selling completed and assembled models?
I'm am looking to sell completed models but do not want to disassemble them. Can someone point me in right direction?

# Answer
> 3 votes
Welcome. You can sell these easily on EBay, just mention in the description that the sets will be shipped assembled. Two things to keep in mind:

1. Since most shipping costs are calculated by box dimensions, your shipping costs will likely be higher than when you ship the sets broken down.
2. Please make sure these sets are NOT glued ... you do not have to mention this in your listing, but absolutely should if they are (even if they are only partially glued).

I have personally bought both assembled used sets as well as disassembled ones, and have no preference. I always disassemble and wash before I reassemble. The only issue I faced was when I bought a set and it turned out to be partially glued, which was not mentioned in the listing. That was an easy SNAD case (Significantly Not As Described) and a full refund from the seller.

# Answer
> 2 votes
I would recommend selling on Bricklink.com. You can create an account, start a store, and begin selling without too much hassle. There are some great guides on how to sell sets on Bricklink, including this one.

You can find more information about Bricklink.com here on Bricks Stack Exchange and here on Bricklink itself.

As far as the actual selling goes, I would simply make sure to describe the set to the best of your ability, as Phil B. mentioned. Is the set missing pieces? Have the colors begun yellowing? Is it glued? Every buyer appreciates a clear description of what they're purchasing.

# Answer
> 0 votes
In my experience the sell on ebay brings a much faster result but with a realistic chance that your price goal is not met. On Bricklink you may have to wait for someone who is willing to pay the price you are asking for, which can take months or will never happen. With both platforms the price will be reduced significantly when you can not deliver the building instruction, it wil be raised when you also can offer the box. Btw, really a nice collection ;-)

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Tags: sets, shopping
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# Question
Title: Why are the Lego boxes so unnecessary big?
I ask myself often when buying Lego why the boxes are so much bigger than the space that is needed for the contained content. It seems a waste in terms of material and logistics. I do store the boxes and especially the bigger sets needs lot of space in my appartment. I would be happy to have them smaller.

# Answer
> 2 votes
The possible reasons include:

* Surface area needed for legal info, practical requirements like barcodes, information, feature descriptions and artwork
* Aspect ratio of the artwork means the boxes can't be too long and thin
* Leaving space between the bricks so they don't get squished up against each other
* Size of the instruction manual or sticker sheet
* Psychological tool to increase the perceived value of the set
* Larger boxes grab the attention of the consumer better
* Larger packages are harder to steal

But the exact reason is likely a combination of some of the above ones and maybe some others, most probably in a top-secret ratio known only by LEGO.

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Tags: packaging
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