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How many rotations or degrees do I need to turn my robot?
I have an EV3 Home edition. I have made a tribot. It has two main motors for the wheels and a caster in the back. To complete a full turn in place I need to set the rotations to 2.32 or 835 degrees.

Does this seem normal to you? I am using The Art of Lego Mindstorms EV3 Programming. The author gets his tribot to turn one full turn in place by setting the degrees to 425. I am just curious about why my setting is almost double. We are both using home editions.

Actually I have answered my own question.  425 is for a 180 degree turn.  Doh!

Glad you figured it out yourself! But just for future reference, it's actually very easy to calculate how many wheel degrees you need for any robot rotation. See this post here.

Also, the distance between the two driving wheels and the speed used can affect how many degrees are required for turning. For example, you may think that turning 90° will make your robot make a perfect turn to the right. That's wrong! It really depends on the design of the robot and the amount of speed used!


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Unidentified #2 bag from 2007 with black and yellow pieces and many black 1x2 clip pieces!
It's driving me crazy! I recently purchased LEGO pieces from a local Goodwill. It looks like there's several Star Wars sets from 2007-2008 that are missing lots of pieces. I was assuming this bag was from a Star Wars set, but I'm not seeing anything that resembles the yellow pieces.

Welcome to Bricks.SE, Amy!
Indeed, this bag is not from a Star Wars set. It is from Exo-Force set 8117 Storm Lasher from 2007. This set contains both the 2 yellow pincer-like blades as well as the concave windscreen in trans-black, and many of the hinge pieces displayed in the left bottom corner of your picture.

Ahhh! Finally! I was looking up the exo force sets too, but i wasnt having any luck! I guess im missing way more pieces than i thought. Thank you so much!!

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


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Two LEGO Powered Up engines with reverse direction
I have 2 LEGO 60197 City Passenger Trains and I would like to attach both sets together and run them on the same channel.
The problem with the current disposition of the bogies is that reversing the powered bogie is impractical. Is there a way to invert the direction of one of the engines in order to make them run together: one engine at the front the other at the rear in reverse mode?

Th easiest solution is to just use port "B" on the rear engine and then turn the "B" side remote control panel 180 degrees.  They will then both go the same direction for "up" or "down". You may even find that having the rear motor 1 click lower than the front is advantageous so it isn't pushing too much in turns, trying to buckle the train.

I think you can use the powered up smartphone app or the lego powered up remote to switch direction of a given motor.
If not you could use gears to reverse the direction of one of the axles. the motor would drive an axle which would gear onto the train wheel axle.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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What exactly does each Mindstorms part do?
It's been a few years since I've bought a Lego Mindstorms NXT 2.0 which comes with the Technic style pieces.
There's beams, axles, rods, connectors... but the majority of the times when I'm building (my own designs, not following instructions), I wonder which is the right part to use. There are usually several options and I never found what is the exact intended purpose of each one.
Is there a website, document, or anything that I could use as a reference for what each part in the Technic set is meant to do?

The best way to learn is to build the robots that come with instructions. By doing this you learn all kinds of ways to put the parts together to make functional models.

I bought a Lego Mindstorms (v2)

Assuming that by v2 you mean an NXT 2.0, if I remember correctly, there is an instruction manual with instructions for a simple wheeled/tracked vehicle, and several other robots are included in the software. Pick one (or all of them!) and start building! You'll notice that there really aren't that many different types of parts:

Beams are the main structural component of the model. Pins and axles connect to them.
Pins connect beams together. They come in several shapes for different situations.
Axles rotate smoothly and support the wheels, motors, and gears. They can also be used as long pins. Use bushings or half-bushings to prevent axles from sliding out of their beam holes.
Connectors like this one allow you to attach beams and other parts at an angle to each other. These big pins are excellent for 90-degree angles.
Gears transfer/multiply torque. See this guide on gears.

For a simple wheeled/tracked robot, the basic design process is:

Build a sturdy chassis for the robot out of beams. Usually this frame is built around the motors. Since the motors are kinda weirdly shaped, consult other robots' instructions for tips on how to position them and attach them to beams.
Attach wheels to the motors using axles and bushings. You can change how fast the wheels move using programming or gears.
Attach the NXT to the top of the robot, so build up some structure from the frame to support it.
Wire the motors to the NXT outputs (A, B, and C), plug the thing into your computer, start programming.

But all of this becomes more apparent and obvious after you've built a few robots from the instructions. Again, pay special attention to how beams are connected to each other to form a chassis, how the motors are mounted, and how different parts of the robot can be reinforced.

Thanks for your detailed answer! I did build all of the robots in the book when I bought it, but I guess I just followed instructions and end up with a finished product, not really learning anything from the process or questioning why each step used the parts it did. I think what I'm going to do is just build them again and this time do it with the purpose of understanding this. Thanks for the links also, very useful to understand your comments.

I'm afraid a guide covering all possible applications does not exist. Actually, this would be impossible as people keep finding (and using) new applications of existing bricks.
Keep in mind people are different. Some just keep using certain parts they are familiar and comfortable with. While others may keep using different set of parts (bricks) for a similar purpose.
To learn different building techniques, it is advised to build other people's creations as building instructions are pretty common these days. You will be surprised when you see what people come up with to solve issues during the creation of the model.


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Looking for an affordable high density storage solution for my individual bricks
As my collection of bricks is growing, my storage space is limited and I'm increasingly interested in doing my own MOCs, I'm looking for a high density storage solution to keep my individual pieces organized efficiently without spending a fortune on it.
The most interesting solution I've found so far is the PapiMax storage box set. However, the price of £85.96 (about €95 or $140) just seems way too steep IMO for only 8 boxes.
Can anyone here recommend a storage system that is similar to the PapiMax storage box set in terms of efficiency but more affordable?
Note that I live in Belgium, so a storage system only sold in the US is probably not going to be an option, considering the huge shipping & import costs that go with shipping from the US to Europe.

Very specific to your region (and mine):
The ALDI chain carries the following hobby sorting drawers from time to time (about once a year):

They are very cheap, about 7 Euro for each type and they are VERY popular with AFOLs in Belgium and the Netherlands. Unfortunately it is hard to predict when ALDI offers these and they are often sold out immediately.

Thanks for the tip. It does look very suitable for small pieces, and I don't think a better price is possible. Too bad it's not only available so rarely :-(

Try "Iris storage drawer" on amazon.co.uk. They sell transparent drawers and boxes in several sizes. These (3 large drawers or 6 small drawers) cost about 30 pounds. They are similar to the system that Jangbricks in his LEGO parts tour is showing.

Thanks for the tip. Someone at Reddit proposed the same storage system, and I found their 8-drawer system @ Blokker for 28.99 Euro... which definitely is affordable. I am a bit worried the trays are a bit big for small pieces, though...

@JohnSlegers i use these style drawers and plastic food storage boxes inside them for smaller parts - allows you to take out just the brick type you need, and as you can get many different sizes of box it makes the space very customisable based on quantity and size of brick being stored.

In this video, I made some boxes out of paper, which is a very cheap way. You can make them smaller or bigger when you want. They are not as stable as plastic boxes, but if you reinforce the bottom with cardboard, they are pretty stable. In this video, you can see my DIY shelf, made from plywood and some bars. In my country you can buy plywood and the seller cuts it if you want. The only thing I made by myself is cutting the 24mm x 48mm bar into 72mm long pieces and glued everything together.

You could also go to AVA and use cheap food containers - the 500ml and 1L microwave ones are quite popular. Nice for parts you don't use too often; but manipulating stacks of those can be cumbersome at times so you may want to build a frame in which to insert them, in which case they can work as makeshift drawers (for these you don't need to buy lids). Not ideal, but could be cheaper and it might be nice to have the same containers for parts you use often and those which are stashed away

Here, my mom found this useful when I had Lego bricks:


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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?

Such a nice collection. Do you have the instructions and boxes? First make sure that you won't regret selling the sets before you offer them. I think Ebay is the best option for (partly) assembled sets. In a local sale, you might have to reduce the prize drastically. I'll have the Caterham, the Simpsons House, Wall-e and the Saturn, thanks :)

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:

Since most shipping costs are calculated by box dimensions, your shipping costs will likely be higher than when you ship the sets broken down.
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.

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.

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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Looking for a spike
I spend some hours looking for the part attached to the microfigure of this picture:

Can anyone identify the spike attached to the head of the microfig.

That does not look like legit LEGO, it looks like a knock off brand

Welcome! Both the gun in the minifigure’s hand as well as the “spike” on the microfig’s head are not LEGO pieces, but third party accessories from BrickArms.
The “spike” is this bayonet piece, and the gun is most likely this piece.
The bayonet:

Thanks so much for the answer!!! i really appreciate it :) Do you know where to find the torso and this head with the bloody scars?


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3rd Party Light Kits
Does anyone have experience with any of the 3rd party lighting kit companies for sets? Do you have any information or stories about how these lighting kits work out in practice?  These are the two companies I am looking at:

https://www.lightailing.com
https://www.brickstuff.com/

The brickstuff system looks really good Very small lights and thin cables. But so expensive! 50 Dollars for 8 lights in the basic kit.

BrickStuff is very high quality, I have used them many times. They are US based, make all their light kits with thought and care, and stand behind their products. I especially like that their lights can be controlled for various light-effects and intensities. Flickering soft lights for candles and fireplaces, bright pulsating lights for emergency vehicles, etc. They are, however, expensive.
I'm not familiar with the other company, but it seems like they are just resellers of the light kits made by Chinese companies and resold by a number of websites (BrickLoot.com is another one that I'm aware of selling these kits, but there are others as well). I do have some samples of these products, and they are okay. Not as good as BrickStuff, but more affordable. By "not as good" I mean that the components are not as high quality, and the connections are often not as clean and nicely finished as with BrickStuff products. You also get a lot smaller variety of lights and effects. But they do work, and are usually cheaper than BrickStuff.
Whatever light kit you end up using, be prepared to be running lots of very tiny and delicate wires. This makes the interior spaces of the buildings/vehicles (where you will be hiding the wires) less attractive and less usable. BrickStuff does have some suggestions of minimizing the visibility of unsightly wires, but ultimately, they can't be avoided.
Having all those wires running also makes the models hard to play with. For example, if you install light kits in the LEGO Modular Buildings, lifting off the floors is going to be tedious. The wires are also delicate, so you want to be careful around them so they don't get damaged. Light kits with wires work best with display models that won't be moved around.
While personally I prefer BrickStuff when it comes to wired light kits, I haven't fully committed to them, as I like to keep my displays modular and accessible for play, display, and modification. Currently, I'm waiting for the release of i-Brix.com products. These are wireless lights for LEGO that work with the same technology as wireless chargers for electronics. The system includes a special transmitting surface that you can place under baseplates, road-plates, etc., and any i-Bricks lights you use over this surface will automatically light up. There are no wires between lights, or the lights and the power source.
I-Brix had a successful Indiegogo campaign a couple of years ago, and they are getting ready for release of the first batch of their products sometime soon. Check their website for updates. I think the combination of wired light kits for stationary displays with various interesting light effects, and wireless lights for moving and more dynamic displays is going to be an excellent combination.

Thank you so much for the run down. While most of my sets are for display, the modular building issue I had not thought of. I-Brix however sounds very promising. I will certainly check them out and see what they offer.

Just noticed these on Brickstuff. Seems to resolve the wiring issue between the floors of the modular sets: https://www.brickstuff.com/store/p111/Vertical_Power_Connectors_%282-Pin%29.html

Yes, that's something they recently added. I don't have it yet, but it does appear to be a great solution.


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What is the three-position lever in the Bugatti Chiron supposed to do?
I've just finished assembling the Bugatti Chiron (42083), and there's a three-position lever in between the two seats that -- probably -- isn't working: one position connects the wheels to the engine; the other two positions appear to do nothing.
The lever itself moves a gear "collar" (I guess) back and forth; that has three positions, and moves correctly.
What's the lever supposed to do? Where did I go wrong in assembly?

A quick look at the instructions showed that pushing it backwards would push the interlock forwards onto gears that connect to the red axles, while forwards would push the interlock backwards onto the gears that connect to the yellow axles - I didn't follow those two axles back to see what they connected to though?

You have two of three right:

One position is the Drive, where the wheels are connected to the engine via the gearbox
The middle is the Neutral, where there is no connection between the wheels and the engine
And the third should be the Reverse, where the wheels are connected to the engine but with passing through a reverser instead of the gearbox.

This is the relevant part, the lever in question hooks into the gray transmission driving ring in the middle and connects the central axle either to the red or the blue gear:

If the reverse is indeed missing, you might have made an error during assembly. Finding and correcting such an error will most probably involve disassembling the whole bodywork and some of the undercarriage, then rebuilding everything back again. For this reason it is generally a sound advice to double-check the parts added in each step and periodically check the already built subcomponents to see if they work as expected.

"For this reason..."; I did; apparently something came adrift when I mated the two halves of the car together.
Even as I was doing it, I was thinking that it'd be useful if the instructions had a section of "turn this thing; this other thing should move" at critical points in construction.
Moreover, it wasn't clear to me at the time what the subcomponent was for, so "work as expected" wasn't really relevant.

We had similar problems with the Technic Extractor and ended up taking it completely apart to reuse the parts for an alternative build.  There should definitely be checkpoints along the way to make sure you haven't made some minor mistake.  It isn't obvious until way too late.

It turns out that the lever works, but in the reverse position, there's a lot of "play" in the drivetrain -- you have to move the car quite far before the engine reacts. That seems odd, but since everything's moving freely, I don't think it's wrong. I had to run it up and down the downstairs hallway, rather than on the dining table, before I got any movement. I think I need to invent some kind of rolling road for it.

I found it much easier installing the wheels and tires at the end of book 1 and testing all of the drive line. If something doesn't work, it is much easier to correct.

@JerryHindman That is what I did too. If you wait until the end to check it is a mess.


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I'd like to build a mechanism to press buttons on a remote control. What is a good basic approach to use?
I have a small remote control like device with about 11 buttons. The centers of each button are placed about 1.1cm apart, and each are about 0.7cm in diameter (this means about 0.4cm between the edges).
For various reasons, I'd like to use LEGO Technic to build a mechanism that can press these buttons.
What is a basic approach I can use to build this?
I've only got a few Lego parts on hand to experiment, and not enough to do anything with, so it's mainly been a mental exercise. Before I go out to buy more, I'd really appreciate some direction in what I can do, so I know what to purchase.

Hi @tamsanh! A few questions to clarify: Are the buttons arranged in a grid, along a line or in a different pattern? Could you post a picture of this device? Are you looking for a mechanism to press any given button on demand (as in a LEGO remote for your non-LEGO remote) or rather program a sequence to press automatically?

Hi @zovits! They are aligned in a grid for the most part, with two buttons slightly offset. The sequence in which they would be pressed will be arbitrary. The plan is to send data to a controller to press whatever combination is required at whatever time.

In that case, you can use any 2 axis system (X-Y or polar, but the first is more suitable for the grid arrangement) to position a "finger" above the correct button and a third motor to move the "finger" to press the button it is hovering over. In order to position the "finger" correctly, I'd recommend investing in a Mindstorms set, either the NXT or the EV3 variant contains motors with built-in encoders that allow for precise positioning. If you have any other questions, don't hesitate to ask them, I'm curious what will you build!

Hey @zovits, thanks for the tip. To be honest, I already have a CNC like machine, and it has been subpar in its performance, hence my wish to move to direct actuation. Perhaps that will have to be a separate topic, haha.

What do you mean by "direct actuation"? Do you wish to have a separate actuator for each button? That would require either 11 actuators or some kind of demultiplexer, be it a mechanical switch (akin to a gearbox) or a pneumatical system with 11 pistons and the corresponding number of valves (and of course their actuators).

Or, if you are willing to stretch the definition of "remote control", you can have a separate pneumatic hose to each of the 11 pistons (plus one to pull the pistons back), and you could set up your side of the remote control with 11 corresponding pistons. But that would get messy and costly soon (but still way cheaper than setting up 11 motors and still simpler than building and controlling a demultiplexer with 11 outputs).

But I still don't exactly get your use case. Do you want to 1) press a button on your remote and this contraption should push the corresponding button immediately, or 2) press a button on your side and the device should press a pre-programmed sequence of buttons, or 3) build an interface that you can electronically control and pushes buttons on the specified input, or 4) something else?

The simplest solution I can currently think of is to use a linear actuator to push the buttons down because they are compact, strong, and have a lot of pushing force.
You can either have one actuator per button or use worm gears to finely move the actuator over each button. This would have to move in both the X and Y direction however because the buttons are in a grid, which is a little more complicated but possible.


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Trying to identify an old 2 x 7 white LEGO plate with a hole in the middle and 4 holes on the side
Recently someone gave me a huge bunch of old LEGO pieces. Among the parts I found a white 4x6 plate with 4 wheel holes (those red wheels with a metal pin), a hole in the middle and an 2x1 extension on one end. Here's a photo:
I suspect that this part is from somewhere between 1960 and 1980. Can anyone identify it? Which sets may contain it?

This is
Part# 824 :  Train Base 4 x 7 with Wheels Holder
It appears in 2 train sets from 1966


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Color Chart Rosetta Stone
After discovering disparities between LEGO color names and families and 3rd party sites, I attempted to compile a sort of Rosetta Stone for the colors. Certain this is not complete but I believe a good start. Hope it helps. https://lego.pandorasdigitalbox.com/lego_color_rosetta.php
Any construtive ideas on how to improve it, or simple help completing it would be greatly appreciated.  Any suggestions or experiences you’d like to share would be welcomed too.

Welcome and thanks for putting this together. Unfortunately this type of post doesn’t really fit this site - a Q&A site - and I have voted to close this question.

My apologies for the mix up, but thank you for the help and information.

Hmm. It's unfortunate that this doesn't fit with the format. I think the link is super helpful, and I'm glad to have it. I wish @Ktulu9876 had enough reputation to ask and answer their own question.

If the link is helpful then it was all worth it. As more colors can be paired up updates will just happen. Thank you again and glad you enjoy the link.

@KurtisBeavers - you could create a question, and then Ktulu9876 could answer it, refering back to his site (and clearly state that this is his own site as a disclaimer - otherwise the answer might get flagged as spam). Something like “There are many different names for the same colors on various Lego fan sites, is there somewhere where you can look these up?”

Why don't we just get creative by slightly editing the cool post?  We just have to tack a question in there and we're good. Hmm.... So, what's a good question to answer?  Oh! Oh! I know!...

@KurtisBeavers Unless I'm missing something, you can always answer your own question, just maybe not an instant self-answer.

You should have added Brickowls color names also.. and i cant get that link to work about 99% of the time i clock on it.

As @AlexanderO'Mara states, this site is a little different from typical forums and the like elsewhere - we're based around Questions and Answers - if Ktulu9876 can post an answer along the lines of "I've created a Colour Rosetta here, it includes details from ..." (so that it's more than just a link answer), we can rework this into an actual question.

@NoobTheory, it seems as though you are looking for a way to associate all the various names of colors from many different sources. I may have an answer for you in the form of a chart that might help you with this. It is not from any of the various LEGO sites and represents work compiled on my own. I hope this helps and answers your question. https://lego.pandorasdigitalbox.com/lego_color_rosetta.php

You can look for missing data in currently available lists:
Old school Peeron (no longer updated)
Bricklink list most of the brick colors available for sale.
Rebrickable has attempted to bring all colors in one place.
Brickset has also some details.
Mecabricks has one also (as PDF).
LDraw project has such list.
It would also be good to define term "LEGO color". Is it for everything released by TLG or just the bricks with LEGO logo on them?
Last thing to note. People still keep finding genuine LEGO bricks made in officially not produced colors. So it is hard to mantain a complete list.
There are few people obsessed with LEGO colors, including Ryan Howerter. He has compiled a list of colors and details around them. If you wish to see these parts and participate in discussion you can get over to Ryan's Flickr picture gallery.

This color chart is from LEGO's Digital Draw program.

After doing a quick skim of it, I know you're missing the "Legacy" colors.  Whatever "Legacy" means here, I don't know.

Colors read from Left to Right:

METALLIC
316 - Titanium Metallic
315 - Silver Metallic
309 - Metalized Silver
297 - Warm Gold
310 - Metalized Gold
LEGACY
298 - Cool Silver, Drum Lacq
179 - Silver Flip/Flop
002 - Grey
153 - Sand Red
025 - Earth Orange
139 - Copper
217 - Brown
105 - Bright Yellowish Orange
003 - Light Yellow
017 - Bright Bluish Green
195 - Royal Blue
011 - Pastel Blue
027 - Dark Grey
009 - Light Reddish Violet
147 - Metallic Sand Yellow
145 - Metallic Sand Blue
050 - Phosphorescent White

Eventually, I would like to see real pictures of a brick maybe a
(2x4) in each color.
Oh, and please add the rendered pictures from LEGO's online
PICK-A-BRICK.  My problem there was with 3 colors Dark Grey, Light
Grey and White. After a while the grey shadows from the virtual
bricks started playing tricks on my eyes making hard to tell which
color I was buying. Very annoying.  I think the site has been like
this since 2008. Eye torture.
Great idea you got here!

Thank you very much, the addition of legacy colors might be helpful. My thinking was at the end of the day, all the pieces are from LEGO. So, I used them as the “gold standard”. Unfortunately they not only no longer have references to legacy colors/color families, most of the time they do not list all bricks in Pick-A-Brick, confirmed by LEGO through a phone call. So I piece nailed between LEGO/brickset. Going to “Missing Pieces” with a recent set number from brickset if necessary, hehe. But the addition of a piece image is a good idea. Thank you again and this project is far from done.

It is a nice idea to have a certain brick in all colors. However, this brick does not exist, as a quick survey of the bricklink catalog revealed. A DUPLO brick was available in most colors at that time! Maybe this has changed after about 18 months.

The DUPLO brick?! Crazy! Nice research on that post too.  Hmm... Well, I'm just imagining a scenario where I'm holding in my hand a brick I would describe as Dark Purple, and would like to buy more from LEGO online pick/brick.  I would never spontaneously think to search for "Medium Lilac".  So, maybe brick shape uniformity should come second, but what's more important to me is to have a real image of any colored brick to compare with what's in my hand, where I could visually verify that even though the duel describing words may be different, the color shades are the same.     .


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Using a remote control for an EV3 robot?
I have just started to get into using a LEGO Mindstorms EV3 robot. I know you have to create a program on the laptop, then it has to be downloaded to the EV3 block.
Can you use a remote control to start the downloaded program with cable disconnected?
I have the Education 45544 EV3 set, but I do not want to buy a remote control if it will not work.

You can't start a program with the remote (8885) or beacon (45508), however you can certainly have your program respond to a remote or beacon if you have the IR sensor (45509). So what you desire can for example be achieved by embedding your base program in one big loop and at the start of the loop have the program wait for a button pressed on the remote or beacon.
Unfortunately the education version does not contain the IR sensor (it is distributed with the commercial version 31313) so you will have to buy that one separately as well...

Hi thanks for getting back to me I am into technic building my son gave me a  mindstorm book I am 73 and very keen learn about programming I think I am trying run before  I can walk what signal does remote control uses to the IR sensor What I would like see in book is a full program so I could see what is happening Its has been less than week I have looking at mindstorm thanks

There's a fan-made book about EV3 programming, I remember it talked about doing a remote control program in chapter 12. To me, you're running at 60 miles per hour before driving at 20 miles per hour, and it should be the other way around.


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What is the name and part number of this round decorative gold part?
What is the name or part# of this round piece? Thanks.

It looks like a Wheel Wagon - Ornate Huge.
You can tell from the link, but as you explicitly ask, I guess I should say that the part number is 15744.


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Advice on Power Functions for an 11-year-old?
My 11-year old son wants to add power to his creations but neither of us know quite how to start this new adventure. He doesn't have any Technic or Mindstorms sets.
Looking through sets online, it seems the best approach might be to purchase the Power Functions Motor Set 8293, along with a Technic set of some sort. He will need instructions to figure out how it works, and then might be ready to build his own creations using the parts he has. (If you can recommend some fan sites appropriate for 11-year olds, that have good instructions, that would be helpful too.)
Appreciate any advice!

The easiest way to start out with Power Functions is to get an official LEGO set that comes with Power Functions. This will allow your child to really understand how Power Functions works.
If he is more into traditional LEGO building with standard LEGO System pieces, one of the LEGO City Trains with Power Functions would be the best options. They include all the Power Functions elements needed to operate the train, and he can also reuse these parts in his own custom LEGO creations once he understands how they work.
If he is into advanced mechanical builds, the LEGO Technic line is a great option. Some LEGO Technic sets come with Power Functions already included, but they tend to be large and expensive. Others do not come with Power Functions, but alternate instructions for adding Power Functions are made available either in the instruction booklet, or at LEGO's website.
Some LEGO Creator Expert sets also have alternate instructions with Power Functions added. The #10257 LEGO Creator Carousel and the #10247 LEGO Creator Ferris Wheel are some examples. Again, with these sets you have to purchase the Power Functions elements separately, but it is made very clear what is needed and how to install the parts. (LEGO Power Functions components are available individually at LEGO's Online Shop.)
Please note that currently there are two LEGO Power Functions systems on the market, and they are NOT compatible. One is the original LEGO Power Functions system (now referred to as LEGO Power Functions 1.0), and the other is LEGO Powered Up (also referred to as LEGO Power Functions 2.0). The new system has similar components, but they are not interchangeable, and they cannot be mixed. The new system works with Bluetooth wile the old system uses IR. The new system can be operated either by a traditional remote or an app. The old system only works with a remote.
So, it is a good idea to make a decision right now which system you want to invest in, and pay careful attention that sets and components you buy are compatible with the system you choose. In general, you can power LEGO sets with either systems, even if it calls for the other system, although some features may not work, or not work exactly the same. The components have a similar size and shape (i.e. you can install the new Power Function system in sets that were designed with old Power Functions in mind).
As far as resources for custom Power Functions projects, I found YouTube to be the most helpful. Power Functions can be a bit complex, so seeing exactly how something is installed can be very useful. Once your son learns the concept of how Power Functions works with an official set, he will start to have his own ideas of what he wants to power. At that point, he can do a search on YouTube, and will probably find someone who already worked on a similar project.
One of the most well-known and respected LEGO Technic and LEGO Power Functions builders is Sariel. His YouTube channel is full of tips, tricks, custom builds, and reviews of official LEGO Technic and LEGO Power Functions sets. His channel is professional and child-friendly: https://www.youtube.com/user/searme/videos
To give you an idea, here is a video by Sariel with some more advanced tips and tricks for using LEGO Power Functions: https://youtu.be/vfIBGIIleCI

Wow, incredible information, thank you so very much for taking the time to write a detailed response. I need to do some more homework for sure, to figure out what makes sense for my guy before investing. I can see what you mean about the various language used... when I called a local Lego store this morning to ask about all of this, the guy told me there's not a lot in production right now for Power Functions, that they're bringing out a new version so I guess that is what the Bluetooth enabled Powered Up type must be about. Okay, more searching and reading to do, thanks again!!

You're very welcome. If you have any other questions in the future, just come back and someone can answer them for you. There are lots of knowledgeable LEGO fans here. :)

I can suggest to look into Rebrickable. There are lots of unique designs as well as modified sets. All come with some sort of instructions.
As a bonus you can add all your sets and parts as an inventory and later check against a model you wish to build. It would provide you with the list of missing bricks.


text:
Where to place your own LDraw parts
I just started designing LEGO instructions. I used LeoCAD to built the model and Web Lic to create the instructions.
Being a Linux developer, Windows is hard to use and access.
It seems bricks should be created with MLCad, but it does not seem to run on Linux. Anyway, I tried creating a brick with vim and information in this tutorial, but can't find where to place my unofficial parts (.dat) files and how to see the result.
How to use my own (created by me) parts ?

By hard to use I mostly mean psychologically.

Staying away from Windows is not something to be embarrassed about.  I'm happy to help keep the Linux users moving forward. :)

Cannot comment on LeoCAD as I've never used that, but LDCad is far superior over MLCad and it works well on Linux natively. LDCad uses same part library format as MLCad - LDraw. You can find LDraw file documentation here.
It is not clear from your question if you wish to create your own parts or just add the ones not currently available in the official LDraw package. If you are interested in the latter, there is a guide. It can be easily adapted to Linux.
If your intention is to create your own parts, LDraw contains nice documentation explaining the file format. The process of adding a newly created part into the library is the same as explained in the section above. Just make sure to put your file for the new part into the .../Unofficial/parts directory under your LDraw package installation directory and make sure to run make-list to include the newly added files in the list of available bricks to build with.

I'm writing my own part using vim.

I've updated the answer. Once you create your part/brick and place into required folder there is a need to generate new parl list. Otherwise applications using LDraw library won't see any changes.

I've found LeoCAD to be a bit buggy on bigger models.  I'm going to try LDCad.  It sounds good.


text:
Which set is this 2 x 6 slope with holes from?
I picked up a bag of loose LEGO at a thrift shop and cannot identify which set this piece comes from:

The holes pass all the way through the slope but have small details inside that prevent a standard technic axle from going through:

If anyone has seen it before, knows which set it comes from or what its purpose is, please let me know. Thanks.

Welcome to Bricks.SE Matthew.  Thanks for the excellent pictures of the part in question.

You have a Fabuland Roof Support Slope, 6 x 2.

If it's like the similar ones I've seen in Duplo, it probably came pre-assembled into one of these:
Fabuland Roof Support with Gray Roof Slope without Chimney Hole

Fabuland Roof Support with Red Roof Slope with Chimney Hole

Fabuland Roof Support with Red Roof Slope without Chimney Hole

Thank you for the information. I would not have guessed that and I spent a few hours trying to find it in a database. You have put my mind at ease.


text:
How deep can discounts on Amazon get?
I'm looking at the Hogwart Train set on Amazon right now and they are 20% off the MSRP. I recently bought the 60198 set at a 5% discount, now it is 16% off.
I wanted to know typically how deep the discounts can go and how far into a release do they start discounting and how quickly they sell out.
Can people who have a lot of buying experience on Amazon comment please?

For me this is one of those things I assume everyone already knows about, similar to complaints about too many or too long YouTube commercials.  Everyone knows about Adblockers and how a mere 32 second web browser install/restart can nix out a lifetime of meaningless commercial watching.
So, how about online buying? How do I know I'm getting the best deal on Amazon.com?
TRUST ME:
It'll take you longer to read this than to get the results you're looking for ALL FOR FREE!

Go to CamelCamelCamel.com.
In the search field type in the word "LEGO + SET Number or KEY WORD".
Hit "Enter/Return".

WHAT'CHA GET:

CCC price tracks ANY ITEM on Amazon.com.
From the lowest price EVER by date.
To the highest EVER by date.
FOR FREE.
Allows you to set in a price alert (free by email) when an item's price falls to an
entered amount, or by an entered percentage off.
Again, ALL FOR FREE.

BOTH YOUR EXAMPLES:

Example 01:  Search "LEGO Hogwarts Train":
Example 02: Search "LEGO 60198". (last picture.)

List of potential items with that name to click further on to see its
price history.

After you zeroed in on the item you want CCC shows a price history
graph.  Gives options to get email alerts when the price hits certain
threshold on either Amazon or 3rd Party sellers.

FINAL SAY:
I don't know why more people aren't using this it's free and it's not really a secret it must the its silly name that throws folks off...
EXTRA CREDIT:
There's another Amazon Price Tracker named KEEPA, but I've never used it.

As a general practise discount can be quite big (I've seen -50% off) for a small set and tend to be much lower (around -25% off) for a large set.
Discounts tend to vary even during the same day. So it is worth keeping an eye. Some sites, like Brickset tend to announce LEGO sales too. They even have a tracker for Amazon and other services. I suggest to look here to have a sense of understanding how much discounted the set can get.

I picked up the Heartlake Cupcake Store for $8 on Amazon.com last year (RRP $40). That’s an 80% discount. Amazon was the seller.
Often those extreme discounts last only a few minutes, an hour or two tops though.

It can help to clear your browser cookies, or open an incognito window and search for the same set. I've seen prices tailored just for me. Sometimes they're more expensive; sometimes they're cheaper.

I've watched the the BrickSet Amazon.com notices for the last year or so.  Most of the discounts are in the 20-35% range, but sometimes they get up to 50% off for $9.99 sets.  If you're on BrickSet all of the time anyway it is easy to setup your news feed to include these.  When I see one come up I click on any that might seem interesting.  So far the discounted sets have been for things I haven't cared about.  Based on that I expect I will find something that I want to buy 10x of for parting out before I find a set that I want for the set itself.


text:
A Technic set from ~1997 with a long grey batter box
I had a Technic set when I was a teen, about 1997 (by looking at the wheels, see picture). From what I remember, it was a tank truck. In its tank it was carrying 3 C batteries. In the picture, you can see the tank closed above, opened in the middle and on the right, the numbers written on the parts. The number "1-01" (or "1  01") is on the tank's three parts. The other (4351) is only on one of the three parts. I'd like to know its set number so I could find its instructions.

This battery box had been produced in two variations: 4350c01 (without switch) and 4350c02 (with switch). It doesn't seem to appear in a set you describe.
This was probably two sets. The other set has been 8865 since it is the only set to have pictured wheel (part number 3739) in white.

Looking at that part and doing a little digging, could this be the set you were thinking of. it is not a Technic set as such, it is a much older set but it seems to be the only one with a tanker and that wheel in.
Basic Building Set
Item No: 740-1
Year: 1985
https://www.bricklink.com/v2/catalog/catalogitem.page?S=740-1#T=I

740 set mentioned here doesn't include pictured tire (part number 3740). Here is a list of all sets with 3740 part included: https://www.bricklink.com/catalogItemIn.asp?P=3740&colorID=11&in=A And 8865 set is the only produced with that wheel in white: https://www.bricklink.com/catalogItemIn.asp?P=3739&in=S

Thanks Alex, as I guess I did mixed 2 sets, since I remember the Technic set 8865! ... And that's what I was looking for!


text:
How much does the full-size LEGO Bugatti cost?
I read that the LEGO developers have built a real driving Bugatti from Lego Bricks.
Did they only use original LEGO parts? Which ones and how many? Which sets does one need to buy and how many? And how much would that cost?
And bonus question, is there a "legal" (LEGO only) way to make it faster?

From Top gear's article on it:

This was laid over a steel frame; one of three ‘parts’ that aren’t actually Lego (the others being the real Chiron wheels and a steel roll cage).

So no, not only original LEGO parts. I don't think (and can't see why they should have) kept track of which parts they used, so noone can really answer the rest of your questions, but from the figures we know (for instance from the linked article):
- 1 million Technic pieces
- 1,5 tonne
- 2304 motors
we can estimate the price. As a significant part of the pieces are probably in the expensive end (an average weight of 1,5 gram matches that), 1/3€ is probably not completely off as an average piece price. Motors are significantly more expensive, they haven't said (or I haven't read it at least) what kind of LEGO motors they use, but they cost 10-20€ a piece, giving a total for the motors of at least 20.000€, so in total the car might only (compared to a real Bugatti Chiron) cost ~350.000€, and then there's the "13,500 man hours", salaries vary a lot, and if you were to replicate it you would actually have to pay it, just spend the time, and it is more than 1,5 year (working 24 hours/day).
Edit: I forgot the bonus question. The 2304 motors they used take up a bit of space, and typically LEGO motors aren't manufactured to have a very precise speed, so when connecting more I would think a differential would be need for each (except the first), they also take up space. If you could fit more motors (and differentials) in there, you would theoretically increase its power, as things are I think (but the physics is not really my area) it's hard to tell if it would manifest itself as more speed and if such how much, but it wouldn't be impressive. I don't see any other ways to increase the speed than adding more motors.

Naah, you just have to switch the small and the large gear and it goes twice as fast :)

You don't have to use a differential to connect two motors, even if they do move at slightly different speeds. A slower motor will put a small load on a faster motor. But practically that will probably be less load than the friction of a differential block, and both are negligible (<1%) compared to the load of the vehicle.


text:
How tall is the Saturn V set in LEGO units (studs, bricks etc.)?
I'm building a MOC to scale with the Saturn V set and am having trouble figuring out how tall the 1st stage engines are but the entire thing would be really helpful! Thanks!

I know this is already solved, but based on one of the amazon reviews it stands over three feet tall. And yes, I know that's not specific enough.

I've been contemplating this question for quite a while.  In the great tradition of this site I felt this needed practical verification.  I decided to make a ruler based on scaling up set 5005107, LEGO Buildable Ruler to measure the Saturn V myself.
tl;dr
| STAGE             | Studs Tall | Bricks Tall |
|-------------------|------------|-------------|
| S-IC first stage  | 52.2 studs | 43.8 bricks |
| S-II second stage | 33.8 studs | 28.3 bricks |
| S-IVB third stage | 50.5 studs | 42.1 bricks |

My conversions are not perfect based on the calculator, but they're close enough that I don't think I messed up anything.
Overall
As we know, this is a huge set.  I needed my ruler to be >32 studs tall to measure any of the stages.  Here's my setup:

I've included pictures of the bottoms of the rockets since they nest somewhat so you can see how tall the rocket engine part ends up being versus the entire shell of the rocket.
S-IC first stage
The bottom:

The top:

I read that as 52.2 studs or 43.8 bricks tall.
S-II second stage
The bottom:

The top:

I read that as 33.8 studs or 28.3 bricks high.
S-IVB third stage
The bottom:

The top:

I read that as 50.5 studs or 42.1 bricks tall.

This is great! I'm glad that you are finding things to do while stuck at home. :)

Thanks so much!  I have been working on the ruler for about a year, but I do have much more time lately.

Other answers seem to be focused on stage dimensions, rather than engines as asked in the question, so I'll address that.
Scaling is a pretty easy math. Stud is 8 mm and brick height is 9.6 mm. Given that the entire 100 cm (1000 mm) Saturn V rocket is 125 studs or 104 bricks and half plate high (104.166667).
The real Saturn V is 363.0 ft (110.6 m) tall. So given the height of a rocket of 1 meter scale is very easy to calculate as 1/110.6 or rounded to 1/111.
Now let's get to the size of Rocketdyne F-1 engines made from LEGO. The following image shows side engines are made of just 4 parts (height wise) and are 1+2+1/3+2=5 and 1/3 bricks tall (or 16 plates). Converting to studs we get 6.4 studs and in metric it is 51.2 mm.

On the box the entire rocket is shown to be 100cm. I just measured the first stage, that is 40,7cm.
Else you can go to service.lego.com and download the instructions aand start counting/calculating (the studs face in different directions, so you can't just count).


text:
What is the name or ID of this mechanical part with multiple pin connection points?
Trying to locate this particular piece on BrickLink though I’m not having very much luck. It’s appears to be a grey bar piece/ zip line bar of some sort. Any assistance you can provide is greatly appreciated

I think this is Part # 30375 : Torso Mechanical, Battle Droid


text:
Ordering of Pages in Printed LEGO Catalogues
While looking at some of the scanned LEGO catalogues on BrickSet, I have noticed that the UK catalogues (at least the ones I looked into) seem to be ordered "backwards" compared to what I'm used to from Germany: They start with LEGO System (or even Technic) pages, while Duplo is appended at the end (e.g. look at the 1997 one).
In German catalogues, in contrast, pages are invariably ordered roughly by age ranges, i.e. the catalogues start with Duplo, followed by Basic (or whatever it was called in the respective time), followed by "System" (town, knights, space, ...; possibly starting with juniorized town in the years that was a thing), followed by Technic.
Is there a specific reason for that? (e.g. is that the usual way to order toy catalogues in the UK vs. Germany, was it just started differently and then LEGO stuck with its respective tradition in the respective countries, etc.?)

I think this is just basically something they did on purpose. I would suggest that you check more like this to confirm your suspicions, but as far as I am concerned, different countries maybe have different styles of doing things related to counting.

Hi LegoCrusader and thank you for this contribution! I took the liberty to edit your answer a bit, as your age is in no way relevant to the correctness of your ideas or answer. On the other hand, could you please elaborate a bit on what you mean by "doing things related to counting"?


text:
Building advice for "hunched" mech lower torso design?
Another mech based question, let me clean up as best I can...
So, in LDD, I'm working on an Evangelion Unit from the popular manga and anime, Neon Genesis Evangelion, and have decided to build EVA Unit 01 (Picture here).
I've built the entire legs section ("lower" quarters) of the Unit, but am having difficulty capturing the "hunched" nature of the mech in Lego, let alone LDD. I don't even know where to start.
I did find this image online to try and assist me in replicating something similar, but it hasn't been of much use (here). But this image should give a general idea of what I am hoping to achieve in LDD.
Any advice would greatly be appreciated.
As always, thanks for viewing!

Hi GipsyD! I'm afraid I can't see any questions in the text, aside from the one in the title which is unfortunately too broad. Could you please edit the question to include one question whose answer can reasonably fit in this QA format?

@zovits, Unfortunately, I think this is as simple as I can get it without sounding completely obscure. But never fear, I have found a solution to this question, of which can be found below...

This answer is pretty long and complex, so bear with me.
After a couple hours of toying around with LDD, I have finally come up with a design that suits my needs fully within the realm of "traditional" Lego Building techniques.
After digging around in the sub-categories in LDD, I stumbled across this block (here). This brick is essentially what made this entire build possible, as it allowed for the "hunching" for the lower abdomen to be captured.
To capture the hunching nature of this mech, I constructed 3 of these shapes to serve as the building blocks for the lower abdomen.

In the middle of the piece referenced above, a short staff was passed through down the centre of the piece in the hole provided in the centre. This assembly is then connected to a 1x1 brick with studs on all faces except the base. The piece of the staff that is sticking out at the back is covered up with a 1x1 cylindrical piece, making room for the "spinal" assembly of the mech. The entire assembly is then covered up with decorative assemblies and facades, as seen in the picture above.
The result can be seen below --

Unfortunately, no LDD file is provided, only images.
UPDATE
As requested by Aziraphale, here is a breakdown of one of the assemblies making up the hunched nature of the Evangelion Unit. Note the short staff going through the piece reference above, mounted to a 1x1 brick with studs on all faces, before being finished in a 1x1 cylindrical piece with a 1x2 detail plate.

Hi GipsyD, can you please show how the "spinal" element is connected to the surrounding purple elements? This seems to be useful also for other cases with odd angles.

I'm assuming you mean the white piece at the back of each section?

The "spinal" element is the white piece at the back of each assembly, which is connected to the assembly via the 1x1 cylindrical piece, fitted with a 1x1 round piece with a hole in it.

No, I mean how the grey hinge piece is connected to the black and to the purple parts. An exploded view drawing would be very helpful.

@Aziraphale, of course, will update the answer ASAP

Wonderful! The staff is a "bar, 3L", right?  Does it sit tightly in the hinge piece, or does it move?

You would be correct. The bar that connects the hinge to the assembly is a 3L Bar, this is the shortest bar that can be used in normal models before descending into minifigure scales. As the rigidity of the finished assembly. I would imagine that the assembly would sit tight, as it does make use of friction to hold it's form, but it is extremely flexible and moveable, going to become poseable


text:
Which LEGO set did this bags 4 - 10 with castle pieces come from?

I have bags 4-10 of 2011 LEGO group 135149.  I'm trying to find what set they are from. At first I thought maybe a castle due to the doors.
I have pictures:

Bags 5 till 10 are from
70404-1: King's Castle

based on Ladder and Staircase 7X4X6 in Reddish Brown.
It also contain the Plate 4X4 in green, and the door and wall pieces.
Bag 4 is from 9526-1: Palpatine's Arrest

Based on Corner Plate 6X6X45° in Medium Stone Grey and Brick 1X2 M. 2 Holes Ø 4,87 in Bright Yellow.
It also contain the red 2x6 and grey  1x8 technic pieces

Looks mostly from  Set # 70404 King's Castle. Minus bag No.4.


text:
Help Identifying a minifigure head - white, like a mime or clown
I have looked everywhere I know to look but can't find this minifigure head listed.  Any help appreciated.

looks really similar to the sad clown head https://www.bricklink.com/v2/catalog/catalogitem.page?P=3626bpb0915#T=C&C=1
the cross near the eyes are indicative of a clown-like figure, maybe a mime.

Could you confirm that it's a LEGO minifig ?

It is definitely a lego minifigure I got it out of the build a minifigure bin at the Lego store.  I have searched clowns, and mimes and looked through the entire minifigure database on bricklink and can't find a match.

I have looked through all the white heads on BrickLink, and find no match. Since OP said that they found it at the Build-A-Minifig bin, my guess is that it may be a head from an upcoming minifig/promotional item that wasn't released yet. An interesting find for sure!

I think it’s a Lego clown face from a mystery pack. I don’t know what series

I talked to a Lego expert on the lego.com online chat.  He told me that this particular lego head was an exclusive part for the Build a Minifigure bin and gave me the part number for it 6257472 mini figure head #2829.  I didn't know there were exclusive parts in the minifigure bin, I wonder if this is something new.  He seemed quite surprised when he found it in the lego database as being exclusive to the build a minifigure bin.

Great find, and thanks for coming back and letting us know :)

Awesome. Yeah I have a chimpanzee 95327pb02 that is difficult to find because it was in the Build a Fig bin, whereas the alternate print of it (95327pb01) is easy to find because it's included in 2 sets.

@raystafarian good to know!  Not knowing the build a fig bin had exclusives for a minute I thought they were kidding!

@bricknerdz I stopped by build a fig Tokyo today to try to find that head, no luck but they had other mimes I haven't seen

@Raystafarian  oooo cool, did you take pics?

I did not think to, no. Sorry

@raystafarian no worries, it just now has me wondering what exclusives the mini figure bin may have

Nuts. I found this thread while searching for a way to identify miscellaneous heads and read the discussion about build-a-fig stations. That got me interested in finding a LEGO store. googled the closest one and sifted thru a few photos. Lo and behold: a shot of this mime from last year. SF LEGO Store - Mime Minifig Head

Found it on brick link Catalog: Parts: Minifigure, Head: 3626cpb2325.
Title says it's a Minifigure, Head Mime Smiling Face, Black Star Eyes with White Pupils Pattern - Hollow Stud


text:
Arduino-izing LEGO Technic - ideas for a car / vehicle to choose
I am starting a project - Arduino-izing LEGO Technic - and now I need some ideas for a car / vehicle to choose.
This project starts out as a quest to find a way to combine the ease of LEGO Technic chassis building with cheap commodity electronics to motorize and remote control it. I am looking for a car / vehicle that is able to work for this. This could be a simple chassis:
https://www.instructables.com/id/Build-your-own-Custom-Arduino-Remote-Control-and-L/
https://www.hackster.io/Notthemarsian/take-control-over-lego-power-functions-ee0bfa
https://www.instructables.com/id/Raspberry-Pi-Remote-Controlled-Car-1/
This should be a part of a robotics workshop and therefore I need a LEGO-based platform for younger kids who grew up with Lego but cannot afford to spend hundreds of dollars to buy power functions, LEGO motors, IR remote, and EV3. Thanks to numerous examples on the net and several and Youtube tutorials on integrating Arduino with LEGO, I will try to start out with an interesting example.
Starting point: the kids should be able to complete this project with a small budget and I hope to incorporate this into my robotics workshop in the future.
The main thing is, I need to have the rear axle to be attached to a single N20 motor to move the kart forward and reverse via a TB6612FNG motor driver.
Front steering can be controlled by an SG90 servo motor.
Remote control should be able to be accomplished by a cheap IR remote/receiver solution based on

Arduino
Zigbee
Bluetooth

I understand that the IR remote hardware (and the method) is pretty hard part to implement and learn about a remote control system so it was a perfect option for this car.
Since this is just a proof-of-concept project and the design follows function - I need to have an idea.
The main question is: which LEGO car to choose?
How about LEGO Technic-8071 - the Service Truck?
What would you suggest?

The Arduino is a great platform for education and getting to the point of doing interesting stuff quickly.  There are a variety of Arduino shields for doing motor control and many forms of wireless.  A later optimization for you might be to make a shield for your students that merges those functions into one shield.  http://www.epanorama.net/newepa/2017/04/23/lego-power-functions-with-arduino/ is another way to do get your Arduino to talk to the robot.

If I were you, I'd try to use a car chassis as simple as possible.
This would achieve multiple goals:

By using a vehicle with the least amount of complexity you can keep the price low.
By avoiding unnecessary parts the students' attention will not be drawn from the topic at hand, e.g. they will be more inclined to listen and cooperate if they are not wondering about or playing with the bucket lifting mechanism of 8071.
The less parts included in the design, the less chances for something to go wrong.
Some space is needed in order to mount the required hardware (motor, batteries, receiver, anything inbetween) and this space is best left open for easy access to inspect, explain, debug, repair, replace, etc.
This approach leaves many ways to upgrade the "final result", either functionally (adding lights, brakes, etc), aesthetically (building a great looking body), electronically (adding additional subsystems like a parking assistant) or mechanically (include advanced steering geometries, suspension, etc) if you or the students wish to do so.
Minimizing the time required to build the mechanical part leaves that much more time for the intended topic of the workshop (the electronics).

Therefore I'd recommend building a simple steered front axle without suspension, a rear axle that is nothing more than an axle and two wheels and slapping both on a large plate or any equivalent flat assembly.

hello dear zovits, many many thanks for the advices and recommendations. These are very valuable and a great asset of food for thougths.
I will take them into account.  Many thanks again !

I'd be tempted to use the Batmobile (76112) design:

Basically, you have independent motors for the left and right wheels. This allows you to steer quickly and easily without the fuss of a traditional steering system.
The Batmobile is $100 MSRP, and can be found on sale. The included motor controller is Bluetooth based, and can be remote controlled via a smart device or custom software on a laptop. Basically, that set meets your needs if you can afford it.
If that is too expensive for you, I'd still encourage you to consider using a similar design using official LEGO motors. It's relatively complicated to integrate off-the-shelf motors with LEGO (I did this a lot as a kid), and the official motors are actually quite cheap these days. You can pick up Power Functions M Motors for $7.49:

That's $15 for the pair. You'd just need to cut off the Power Functions connector and connect the motor to your driver. This saves you the fuss of mounting your motors and integrating them with LEGO gears and wheels.
This is really outside the scope of your question, but on the electronics side I personally wouldn't use an Arduino. I'd probably go with something that has wireless built in, such as something ESP8266-based. Then, all you need is your microcontroller and motor driver for a working system. The system can be remote controlled from a PC or smart device. You wouldn't even need special software on the remote, as the microcontroller can broadcast an SSID and serve up a web-based controller to the connected device.
So then your BOM would be:

2x PF M Motors ($15)
NodeMCU or other wireless controller ($3)
A few Technic beams, gears, axles, wheels, etc ($5+)
Battery box ($2)
TB6612FNG or similar dual motor controller ($1)

You could probably do the whole thing for ~$30.

This is a great idea and simple to execute, but OP has explicitly stated that a driven rear and a steered front axle is required: "The main thing is, I need to have the rear axle to be attached to a single N20 motor to move the kart forward and reverse via a TB6612FNG motor driver. Front steering can be controlled by an SG90 servo motor."
Your input on the pricing and the recommendation for the microcontroller is nonetheless very valuable.

hello dear jncraton - many thanks for the answer with all the hints - very intersting ideas that are worth to follow. This is truely a great place for all brick-endeavours


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What Is The 3-stud Wide Red Cabinet Frame Piece In Picture?
I would like to know the name and part number for the red frame piece in picture. The one that is holding the white cupboard door.

Hey Nancy!
Part# 4532 Container, Cupboard 2 x 3 x 2


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42043 Mercedes Arocs Truck Crane Turntable Sticking
I have recently found that the turntable of the crane has been sticking when turning! Having taken apart the crane and investigated the issue, it seems to be the interplay between the turntable's teeth and those of the small black cog: they are not meshing smoothly! The cog moves nicely when turning the turntable, but is stuttering and jamming the other way round (the more useful way)!
Any help would be appreciated!
P.S. any tips on lubricating the yellow pistons?

It's best to stick to a single question at a time. Can you post a photo of the cog/gear mechanism you describe?

This is a known problem with that gear combination. It's a flaw with Lego's design of the bevel gears. See this discussion on the EuroBricks forum.
Bevel gears are typically designed to fit with only one other size of bevel gear. Specifically, the cone-shaped pitch of each gear needs to intersect with each other at a single point to ensure smooth operation.
All Lego bevel gears are intentionally designed with a 45-degree pitch so that any gear can mesh with any other. This means that only bevel gears of the same size can actually mesh perfectly, although in most gear combinations, the loose tolerance means the incorrect pitch isn't really noticeable.
However, in extreme cases like the 12-tooth-bevel to 60-tooth-turntable in the Arocs, the gear pitches are so mismatched it creates an extremely "noisy" or "sticky" effect.

I don't have this kit, but when you have an issue with cogs/gears meshing poorly it usualy has to do with how the forces are causing the tolerances to slip. It sounds like the load to the cog (or gear) is such that in one direction they are being forced together.
Ideally, we want gears to mesh within some ideal tolerances, so see how you can reinforce the shaft blocks so torsion doesn't change those tolerances too much.
Also, check for too much backlash, which could show you where the gears are meshing too loosely and then digging in.

The turntable gear you are speaking of has the same connectivity options on both sides. However, only one side of the gear ring on the black piece is actually beveled. If you use the turntable incorrectly (upside down), this will result in poor connection between the gears. So it is essential to place the turntable correctly.


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The Missing Handlebar
I've been trying to look for the handlebar piece but it doesn't show up. Can someone tell me why?

Where are you looking? I'm pretty sure it would show up if I looked in the right pile.

@Henrik unless the vacuum cleaner got it.

I'm not sure where are you looking, but it is readily available on BrickLink in seven colors: https://www.bricklink.com/v2/catalog/catalogitem.page?P=30031&idColor=85#T=C&C=85

Welcome User11225!
In your LEGO program or webpage type in the part number instead, which would be, "30031".
Why: Search words vary across media, and it's harder to misspell or mis-describe numbers.
Example:

On Bricklink.com the description includes the "s" to spell
handlebars.
In LEGO Digital Draw the description just calls this piece a "handle"
and drops the "bars".

Search fields can get finicky.


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Modified 3x2 Plate with Rubber Bristle Bottom and snap-on cover?
I've had this odd little part laying around my desk for some time - does anyone know what it is?  There's no Lego logo anywhere, and I've searched BrickLink somewhat comprehensively, so I'm guessing it's from a compatible set.
It's a modified 3x2 plate, but without a hole, and the red bottom part is sort of a rubbery, grippy substance.  The "cover" is softer, non-ABS plastic, and can snap onto the plate either way.
I'm guessing it came from my wife's nephews in a whole pile of stuff they gave us - mostly Lego but there was some MegaBloks stuff mixed in too.  Probably not from after 2000 at the very latest.

Definitely not LEGO. Part with red insert seem to represent a brush. Do both pieces come apart easily?

The two pieces are not difficult to get apart - it's clear the one is supposed to be a "cover" for the red part of the other.  The red stuff is a rubbery substance - like it was supposed to provide traction or something.

Is it not normal to close the newer question as a dup of the older one (granted the quality is about the same)?

So, the curiosity bug bit me again.  The mysterious part appears to be a Kre-O "Motion Brick" which appeared in various sets. In my research I found that there is a variation (hollow vs. solid) in the studs, as shown in the picture.


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Read power usage and respond when motor is straining
Is there a way to know if the drive wheels are "straining", like when locked up with an opposing bot?
This is for a Lego sumo bot using the Lego Mindstorms Education EV3 Core Set (EV3 Large Motor 6009430 and Lego Mindstorms EV3 Home Edition).
The approach that should have worked is based on the difference between the "regulated motor" green block and the "unregulated motor" blue block. The regulated motor retains a consistent speed, adjusting the power necessary to keep that speed, while the unregulated motor sends a constant power so the speed may change based on resistance.
There's a yellow block called "Motor Rotation" which has a setting to read something called the motor's "Current Power". Instinctively, I figured that would tell me the power being sent to the motor, so if it was driving using the regulated drive block, I would expect to see a number that would go up when the motor encounters resistance and needs more power. (And the number would go down hypothetically if the bot was going downhill and needed less power to maintain speed).
But, in practice, the number returned from the read "Current Power" matched the speed number I sent to the regulated motor block, and when resistance was applied, the number went down. I tested this by having the number displayed on the screen, the number displayed matched the "Current Power" number shown in the live "Port View" in the Mindstorms computer app, both went down when the wheel slowed.
Is there a way to read the real "Current Power"?
Is there any other way to know when a motor is straining?

I was playing around with my EV3 robot and I intentionally prevented it from being able to turn a full 360 degrees. Right out of the blue when it couldn't move a full rotation the EV3 light started blinking orange. When I let go it turned the rest of it's rotation and the program stopped, which makes sense since there were no other instructions for the robot to complete. I repeated this process and got the same results, and that was odd since the program didn't interfere with the light in any way.
I found out a few details about this:
• Even after you let go, the flashing orange light still stays.
• It occurs when the EV3 cannot move it's motor(s) far enough (in this case the big servo motors), specifically when it can't even budge.
• The program will not continue unless you allow the motor to continue it's rotation.
• It doesn't seem possible to program the EV3 to stop the orange light after the motor can continue it's rotation (or maybe it is, I'm not certain).
Again, this doesn't suit your needs, since the orange light will remain from that point on. The energy meter probably doesn't tell if the motor is stuck, and this automatic light system isn't suitable either. But at least I tried!

I don't have this project anymore, but if I were to continue on it, I'd try monitoring the degrees of rotation over time compared to an expected rate if the motor was under a normal load.  That's a good hint.

I believe the orange light indicates low battery or excessive motor strain, and I have noticed that it switches back to green after a short delay. Probably the one 360-degree turn did not last long enough for the light to return to green.

When I was looking in the sensors tab of the LABVIEW EV3 block-based coding software, I saw something that kind of looked like an alternative NXT Brick.

It was actually an Energy Meter, and because of its name, I thought it would suit your needs. However, it's wire port looks like it's intended for Lego Power Functions, but if it's in the EV3 programming software, then obviously there must be some sort of way to get it to work with EV3.

Have you checked what "Energy Meter" actually is? I don't think it is supposed to work in the setup described by OP. It has both PF and Mindstorms type connectors. With later one supporting the so called "E-motor" only.

Some details about "Energy Meter" can be found here: https://le-www-live-s.legocdn.com/sc/media/files/user-guides/mm/9688-energy-meter-guide-e526319e083ac417918f4fa7c1563fc1.pdf

What a curious little product.  +1 for including a link to the PDF.  Looks like this is designed to use a motor as a generator (motor becomes an input to the battery unit and some mechanical force pushes the unpowered motor).  Doesn't like up with the OP though, and is for an older version of Mindstorms NXT.

@efreed If it's in the EV3 coding software, then isn't it meant for EV3?

@mindstormsboi I thought for sure I saw a picture of an NXT device when reading the PDF, but must have been reading to fast.  I take back my NXT comment.  It's still a +1 for finding this, but it does not make possible monitoring the load/stress of a drive motor that is in use.

@efreed I have updated the answer and found another feature, but as of now it's quite pointless. Maybe you can contact Lego customer service and tell them about this and ask that the light turns off after motor can continue rotation, okay?

Or maybe there's a way to program it to flash green after you physically allow the motor to move?

@mindstormsboi You may have stumbled on something with monitoring the degrees of rotation over time compared to an expected rate if the motor was under a normal load.  I don't have my EV3 anymore to test, but if you post something like that as a second/separate answer, I'll mark it as the accepted answer.

@efreed I've made it a separate answer now, I hope it satisfies you.


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What is the model/year of a white and yellow airplane with a sticker "96" on the wing?
I found this airplane in a bag at Goodwill, but not sure what set it's from. It looks complete and the landing gear pulls down.
Any idea what year or set this is from?

It is 42044-1: Display Team Jet from 2016.

Thank you so much for the fast/accurate information!


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Buy the complete EV3 set or only the brick?
I have an old NXT (or NXT 2.0, do not remember exactly) bought I think in 2007.
I would like to upgrade to EV3, but I am not sure if I should buy the complete set or only the central brick.
Is there any news about a possible new programmable brick in the near future?

Since the NXT 2.0 was released in 2009 you must have a first generation NXT set then. As per this question the peripherials (motors, sensors and of course their connecting cables) remain compatible. So you could just get the central unit and use the already owned NXT components. Keep in mind though that all parts (motors, sensors) have since been redesigned, so the EV3 versions will likely work better, and don't forget that the EV3 set includes an infrared sensor as well, which was not present in the NXT complement.

Well, then maybe it makes more sense to buy the complete set, so that I also have more components. Thanks

I've yet to find someone who prefers the infrared sensor to the ultrasonic sensor though.

From financial point of view it would be more cost effective to buy a single EV3 brick. However these are rarely sold alone and the price for extra parts could be negligible if bought as a set. It might be easier to find a good deal for a set as well.
It is hard to say if LEGO is looking to release EV3 successor. However LEGO has released a new series of powered electronics as they call them "Power Functions 2" or "PowerUp" with pretty much same specs as previous series, but with new type of connector. This connector is very close to one used with EV3, but different. The whole range is designed to be used with basic robotics system (Boost) as well as general consumer sets (Trains), basically making it one-fits-all. So there is some hope we might see proper robotics system in not so far future.


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How did this 1x4 plate look like before modifying?
As you can see someone modified this 1x4 plate. Can you tell me which brick this was originally?

My guess is that it was a Hinge Vehicle Roof Holder 1 x 4, but there are probably several pieces you could have modified to look like that.

This seems likely to be correct.  But it leads to other questions like... why would you go to that much work to end up with a 1x4 plate?

It looks pretty old... probably from back in the day when you didn't a magic machine that can deliver anything you want to your front door. Especially LEGO!!

@chicks I am interested in sets from the 80ties and 90ties, buying them used and on regular basis have to see in my used part inventory for single items. Right now i need 3 of those 1x4 plates white. I have to order them at Brinklink so I am thinking about using this item ;-)


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Where is an instruction sheet for Ausini set 25418 guitar?
I bought an Ausini brick set AUS-25418, which is a guitar, however as cheap as it was the price, it didn't have the building instructions, at least it looks like no piece bags or stickers are missing.
Does anyone happened to have those around? I would really appreciate any picture you could send me.
Here is a picture of the model:

I Googled for them for some days and send messages to a distributor but never received a reply. I even tried to build it from pictures of the finished model with no success.

Attack on the Clones: The Purist Punch-Back!
I'm posting up these clone brick instructions at the very bottom below, but I'm going further by offering a free digital instruction file to build this model with official LEGO bricks through Bricklink.com instead.
This model has 3 pieces that aren't direct clones,so they don't exist in LEGO, but we can easily use alternative pieces and make their need a non-issue.

2 x 2 plate with Inverted Studs.
2 x 2 1/3 Curve Top Brick.
Roof Tile 2 x 2 x 2/3 Plate.

The only left over issues are the stickers (the "wow" text, blue flame effects), and the screen printed 2x4 black tile, which represents the six round yellow tuning pegs on the headstock of the guitar. I haven't looked for equivalent official LEGO ones, which may or may not exist.
I just used an alternate build to replace all printed art that came with this set.

These clone knock-off brands are straight up shameless.  It would be just to reverse their blasphemy, knock them off financially, and offer plans to their designs in official LEGO for free.
I wouldn't mind finding the most interesting/popular Clone Brands, and just go to town on them. I realize in most cases it will be more expensive, but at least there will be an alternative for the purist who might be less inclined to patronize these clone pirates.


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Why are printed LEGO Catalogues distributed late?
Today is January 29, 2019, and toy stores in Germany (at least a couple that I've checked) still have only some remainders of 2018 July - December catalogues. 2019 January - June catalogues are nowhere to be seen, even though the first month of 2019 is virtually over already. As far as I remember, it has always been like this over here already during my entire childhood.
Why is that? Why do the printed LEGO catalogues not show up in stores at the beginning of the year, at latest along with the first sets released in the new year?
I have heard and thought about various reasonings over the years: That they wait for some toy industry fair before revealing the entire programme for the year (seems unreasonable in light of the complete novelties being visible on the web already), that they hope people will buy a first set in the year solely in order to get to see the included (smaller) printed catalogue (that strategy might work, it's precisely what I used to do as a kid every January ;) ), etc. Is there a publicly known reason for this delay in releasing the printed complete catalogues?

Might be another regional thing, because where I live we get our catalogues several weeks in advance.

I doubt that there is a strategy behind it. They probably noticed mistakes in the catalogue that could not be tolerated, and had to reprint the whole thing.

@Aziraphale: Then why is it like this every year, for the past 30 or so years?

Reviewers seem to think that this situation is exceptional and last year, the 2018 catalogue had been available even before January. See e.g. https://youtu.be/n5GSxr3xC68


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Narrow gauge train wheels metal axle?
Anyone know some way, (or someone that makes a mod) to make narrow gauge wheels that actually roll fast? Something similar to the metal axle trucks that are used for standard gauge trains.

Do you mean for lego train wheels that are plastic?


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Help identifying LEGO sets - Star Wars?
My toddler inherited a bunch of LEGO pieces that all seem to be Star Wars.  I was able to determine about 1/2 of the bunch were 4 Microfighter sets since some parts are unique.  I am stuck identifying the rest.  I have “two” very unique items but just can’t seem to place them... !
One item is a dome with a hinge and it has ‘paneling’ Design but it is not like the domes I’ve seen on tie-fighter sets, the other are sticks w/ a 1x2 on one end and a circle on other that are about 3.5” long.

Welcome Court!
Looks like  part# 42445 Bar 12L with 1 x 2 Plate End Solid Studs and 1 x 1 Round Plate End.
Part# 99784 Bar 12L with 1 x 2 Plate End Hollow Studs and 1 x 1 Round Plate End.

and
part #50747pb06 Windscreen 6 x 6 x 3 Canopy Half Sphere with Dual 2 Fingers and SW Tie-Fighter Pattern.

From
Set #9492 TIE Fighter.

Later!

Wow, thank you so much!  I knew this would work, these pieces were way too specific.  You are awesome!

Just a subtle correction: these are 99784, Bar 12L with 1 x 2 Plate End Hollow Studs and 1 x 1 Round Plate End.

Thx Aziraphale!


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What are the structural difference between a minifig and a minifig on a keychain?
Are there any differences in the components or construction of keychain minifigs compared with regular minifigs from sets?

A minifig on a keychain and a regular minifig are essentially the same. They are made of the same components. A couple of additional procedures turn regular minifigs into keychain minifigs.
1.) There is a long screw inserted through the head and neck-post of the minifig to be able to attach the keychain to the loop at the end of the screw. If you remove the screw, there will be a small hole left inside the stud on the head, and on the neck-post.
2.) The leg assembly is fused to the torso assembly to make sure they don't separate during use as a keychain.
In addition, keychain minifigs are made in China, so there is a slight difference in how they look. The plastic has a duller and sometimes a bit more opaque appearance compared to regular minifigs. The printing, however, is the same quality, which is what most people focus on. The difference in the shine/opaqueness is usually only noticed when the keychain minifigs is placed next to an identical regular minifig.

Do we know if the legs are glued on or if the plastic is molded differently to make it more resilient?

pretty interesting. Does the slight difference of China figs also apply to figs from the 90ties?

The plastic pieces for the torso and legs are exactly the same as regular minifigs. They are not glued, but the legs are fused to the torso with a solvent, that actually loosens the surface of the ABS plastic and allows the molecules to combine. Once the solvent evaporates, it leaves behind a cleanly fused surface with no residue at all.

LEGO has been using two types of solvents through the years to "glue" minifigs, sculptures, etc. One is called MEK (methyl-ethyl-ketone) and at some point they switched to GBL (gamma-butyrolactone).

@Fabian, the collectible minifig series didn't start until 2010. At that time, LEGO didn't have their own factory in China, but worked with a partner. Now they have their own factory and are more in control of the quality. According to the official LEGO history site,  https://www.lego.com/en-us/themes/lego-history/ LEGO didn't start working with Chinese partners until the 2000s, although it is possible that some of their non-brick items were made there even before (stationary, school-supplies, home décor, etc.)


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Is this gray clip hook an original LEGO part?
Is the gray "hook" an original LEGO item? Please see the red plate for size comparison.

This looks to be Arm Piece with Towball and Clip.
There are quite a lot of copycats these days. So there is always a chance it is clone piece. To confirm this is genuine LEGO piece best thing would be to look for LEGO logo, but it is not always available on small pieces. Alternatively you can look for "30082" which is a part number.

yep, that's the one. thanks! I am pretty sure it is genuine because it came with an old set which did not seems to be contaminated with modern fake parts

do you now where exactly the piece is used? on the arm of a minifig?

It is quite versatile part since there are at list 3 ways to connect it: 1) using the clip; 2) the towball; 3) the whole in towball (for a rope). There might even be 4th one - the bar between clip and ball, but I'm not sure it is wide enough for another part with clip. So there are many ways to use it. Do you happen to know which set this part came with?

in this case it appears in sets 6544 and 6339 - the space shuttle with plane or lunch pad. it is holding a satelite in the cargo bay of the shuttle

apologies, this is not the piece on those shuttle sets, it is item number 3614b


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Help identifying piece - wheels on arched base
I'm not familiar with this piece that showed up in an old bin of Legos from a second hand store.
The text of the copyright reads "2008 the LEGO group"
Is there anyone that can tell me a part number or set this might have come from?

this is: Part # 48394base
Bricklink:
Sports Promo Skateboard Base with Four Wheels from McDonald's Sports Set Number 7, Set 7921
Brickset
Set 7921-1: Skateboarder, Grey Vest


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How do the DUPLO Action Bricks work?
Does anybody know what is the technology the DUPLO Action Bricks are based on?
It is not any RFID or NFC because I printed out the white one on normal white paper which turns lights on/off. The symbol on the brick is not important - even a white paper with a printed symbol of rain drop turns the light on/off.
I'm not able to make coloured ones - blue, red, green or yellow. Is the exact color shade so important? If so, then how can one make their own Action Bricks?

Does this answer your question? What is the function of Duplo part# 38507 RAIL ACCESSORY, NO. 4

It doesn’t actualy. I needed to know how to make it. So the answer is to use correct color.

It is about color and length
The Duplo action brick uses a color sensor, so you want to use the correct colors
and it needs the length of the brick for the sensor to determine the color.
paper replacement (youtube)
How to 3d print your own

Color sensor for some amount of time.
I was able to make green Lego tiles work, if the area I covered was 2x8 (in LEGO scale, not DUPLO) bumps.  I put a standard Lego scale 4x8 brick under the Duplo track piece, and then built up the exposed area to the height of the center of the Duplo track, and then put 2 green Lego tiles (1x8) on top.  This worked really well, but is not child safe.

Trans green (even with solid green underneath) does not register.
I ran two tests to verify this.
I cut the center tie out of a piece of straight Duplo track.
I used a standard Lego scale 4x12 centered under the piece of track.
This alone, did not cause the train to reverse (due to distance from sensor).
I then built up the area by putting a Lego 2x8 on top, taking the Lego bump top to the same height as the center tie would have been.
This was a tile less deep than my previous test.
This worked, the train did reverse.
This also worked with a 2x10, but only the length of 8 was needed to trigger the reverse.

I then tried using a Trans Green duplo track (without the center tie cut).  I put the standard Lego scale 4x12 underneath and then built up the area on each side of the tie with Green Lego 2x4 bricks.
This did not work.  The center tie, where the color was trans-green (on top of regular green), was an interruption.

None of my solutions are considered child safe.  But if this is not a concern, I recommend the solution that does not alter the train track piece, and using Lego scale 1x8 tiles.

If choking is a concern, the solution where I cut out the center tie, and then use large standard Lego scale green bricks, is a bit safer.  But even this solution, where the smallest brick is 2x10 (standard Lego scale), does not meet child safety requirements.
I bought some extra green Duplo smart tiles.

As seen in this question there is a sensor below the train. This is most likely to be a color sensor which is how it detects action brick.

The following is deduced from looking at the train and its reactions on the tiles. (I know about electronics)
It seem that if no reflections are detected within approximtely 1 second, then the train switches off. In normal driving, the gray track parts reflect light on/off. But if you lift the train, then it sees no alternating reflections - and stops.
The colored tiles:
Looking at the bottom of the DUPLO train, you see a tiny window. Inside this is a 3 color LED diode. It looks as if the diode is cycling through the colors black (actually off) - red, blue, green, cyan, magenta, yellow, white.
These are the colors possible if each diode is just switched on or off
(I dont know if it uses brightness modulation - but I think not)
In the window is also some light detector, measuring the amount of reflected light. So a red tile will reflect a lot when the red LED is on, but a green tile will reflect very little when the red is on.
This provides 7 possible tiles for the coding.


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Can anyone identify this small 1x1 round brown part?
I have 4 of these unidentified parts and I'm not sure which set the originally came from (stud shown for comparison).

Those are Wheel 8mm D. x 6mm
Bricklink.com
In brown they were often used as wheels for cannons on sailing ships or castles.


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Unsure of how to use a switch that is time dependent
Have been trying to make a line follower that can auto-correct itself if it would lose the line. The follower is supposed to turn around, go forward and catch the line if the line has not been detected for about two seconds.
Can this be done by using a switch block where my current program goes into the true slot and the auto-correct in the false slot?

You have not provided your programming language of choice, so I'll answer in pseudocode which can then be adapted to the specific environment.
It should be possible with the following construction:
do {
  if (on_line) {                 // this may be a variable you update periodically or a method to call every time
    last_time_line_seen = now()  // remember that we have seen the line at this time
    follow_line_as_usual()
  else {                         // if the line is currently lost
    if (now() - last_time_line_seen > 2_SECONDS) {
      turn_around_go_forward_catch_line()
    } else {                     // we are off the line but the two seconds have not passed yet
      do_something_else_like_go_forward()
    }
  }
  wait_some_time()               // optional, may not be needed
} while(stop_condition)          // if you have a stop condition

This works by storing the timestamp of the last known time when the line was seen, and checking if that was more than 2 seconds ago in the case the line is currently lost.
I haven't seen in your question what your robot should do if it has lost the line but the two seconds have not passed yet so feel free to fill that part with any behaviour.


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Where to get bulk GBC soccer balls?
I am running a middle school robotics club, and this year we are focusing on building a Great Ball Contraption (GBC). One problem I'm having is acquiring the balls. On BrickLink, the discontinued soccer balls are going for nearly $1 each, and I figure we'll need about 200.
Any ideas?

A quick search on Eurobricks says a lot of people just get bulk cheap 14mm plastic balls.

Do they have to be lego balls? Why wouldn't marbles or something else work? Those would be way cheaper and easy to acquire.

You should research if there is an RLUG (Recognized Lego users group) active near where you live. These are groups of LEGO fans for which the LEGO company provides various levels of support.
Often they have the means to buy LEGO directly from the LEGO company through the LUGBULK program. The program allows the members of the LUG to buy LEGO in bulk directly from the LEGO company itself at a discount rate.
I have in the past succeeded in purchasing a reasonable amount of soccer balls this way (among various other elements).
However, there is only a narrow time frame in which you are able to register for the program and it takes nearly a year until the lugbulk is delivered, sorted and sent to the various members. I'm not sure if the registration is still open or already closed. At least the final selection of items hasn't happened yet AFAIK, so perhaps your RLUG can still select the elements as a favor...

Registration for the current one closed just a few days ago.

While LUGBULK seems a good option it takes quite some time before ordered items are delivered. It takes almost a year. So it is a good option for those planning way ahead.

On LEGO's customer service under "Bricks & Pieces" (not sure what it's called in english the page is in danish here, and I couldn't quickly see a way to change that) you can buy parts. If I search for part id 6261264 (an orange "BALL Ø14,2"), it "only" costs DKK 4.94 which is ~$0.76, quite a bit less than $1, and shipping is usually quite cheap from there, but I think there's a limit on 100 of each piece, so you might need to make more orders.

Correct URL is: https://www.lego.com/service/replacementparts?chosenFlow=3 for the Bricks and Pieces service.

I got them from here; https://pv-productions.com/product/lego-gbc-balls/ work perfect in my gbc modules. Also they have very cool glow in the dark gbc balls

Here is a link to LEGO compatible soccer balls. These GBC balls work flawlessly and were tested at the Brickworld Show on several dozen GBC machine. The balls are still working and are GREAT!
100 pcs = $22.77 or a sample pack of 25 = $9.48.
https://www.brickloot.com/products/white-soccer-balls-for-gbc-great-ball-contraption-fits-lego-balls
Note: I work for Brick Loot on our Original Light Kits and Light Linx, Brick Loot's DIY Lighting items for MOCs. Basically my title is "The Light Guy" lol. If you were at Brick World Chicago you may have met me as I am always there :)

Thanks for sharing this. Are you affiliated with Brick Loot? It's not a problem if you are, but we do ask that you disclose this in your answer.

No problem and happy to. I work for Brick Loot on our Original Light Kits and Light Linx, Brick Loot's DIY Lighting items for MOCs. Basically my title is "The Light Guy" lol. If you were at Brick World Chicago you may have met me as I am always there :)
I would like to send you free a pack and up to 2 more mods or highly trusted members you suggest to check them out for free. Please LMK @jncraton♦

Oh cool! I've updated your answer to include this disclosure. I haven't done GBC, so there's no need to send any of these to me. We don't really have a platform for reviews. We try to stay pretty focused on being a Q&A site, but if anyone else here wants to put together some sort of Q&A content testing these out or comparing them to official parts, I'd personally be open to that.


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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.

The bag date and number are for the bag, not the set FYI - see comment here

Thank you! First time really getting into legos now that I have a little boy that’s interested!

Looks like set 79108 Stagecoach Escape by matching the horse, saddle and the minifig head.