text:
Is there a way to plan and organize your LEGO project like a GitHub hosted software?
I have the idea to host, plan and maintain a LEGO project (building a MOC in several steps with different functionalities) like a software in GitHub. The project should have forks, pull requests and version tracking.

Is there a possibility to do this with existing software? LDD, Leocad, Stud.io in combination with GitHub or similar?
How to realize a crowd/community project that builds on a LEGO model? What functionality might be needed?

https://github.com/chicks-net/lego-business-card-holder is my example of what you're talking about.  I wasn't expecting much collaboration, but I like github for publishing things and showing the history of the project.

Can you export it to a data plan like JSON or XML? Those are versionable, with a bit of work.

While you could indeed manage the project with a tool like GitHub (using the Issues feature), you might be better off initially managing the tasks through a tool like Trello which allows you to create tasks and move them through various status (i.e. Planned, In Progress, Review, Complete) in a fairly simple, intuitive user interface.
An issue with managing the actual project files within source control is around the format of them - some file types work better than others when it comes to source control, and some formats of those types work better than others as well.
Git is a "Distributed Version Control System", which means that anyone can work on any file in the repository on their local machine - this is usually fine when working with text based files, but is not so good when you have binary files, because understanding the differences between two versions is often not easy. If the tool you choose stores projects in binary files, Git is probably not the best option.
I would strongly recommend that you consider a Centralised Version Control System such as Subversion (SVN) or Team Foundation Version Control (TFVC or TFS) as this allows your collaborators to "checkout" or "lock" a specific file to say they are working on it, and then when they've updated it, "check-in" their changes - this will (hopefully) get around the main pain points of trying to merge changes in these files, albeit with the caveat that you might still have people check-out a file and then "go dark" and forget to check it back in for a long time.
Sadly for you, most developers have moved to Git based source control, as it's very good at dealing with code files, and generally much quicker when working locally, allows for "offline" working, etc. and solves the problem of people working on different parts of the same file or project simultaneously, so most of the free options (GitHub, GitLab, etc.) focus on that. You might be able to use the free options within Azure DevOps to create a TFS based project, or find another SVN host for your project. Most of these also offer "Work Item" tracking for task planning and management.
In terms of the current software for building your MoC, the likely contenders are:

Stud.io - uses a binary (.zip) format. This doesn't play well in Git. Furthermore it's a password protected archive, so you can't easily extract the underlying .ldr files.
LDraw - uses a text based format. Potentially a better fit for Git, however the format itself would be very easy to mess up in merges if two people work on the same model files at the same time.
LEGO Digital Designer - uses a text (XML) based format. Potentially a good fit for Git. While XML can get messed up in merges, it's usually easier to see in merge tools where the changes should belong, and so easier to correct/adjust if two people work on the same model file. However, this is likely end-of-life now, especially with the announced purchase of BrickLink by The LEGO Group.

What about Studio and LEGO Digital Designer – what will happen with the
  two digital building experiences since they’re quite similar?
  The LEGO Group is planning to support and evolve Studio and will review opportunities
  for both services following the closing of the deal.

I would say that regardless of the file format, text merges do not make sense for a Lego model and even a human readable format should be treated as a black box.  Sure a merge might handle a color change correctly, but even if one piece is swapped out I bet any idea of a "merge" would be impossible.

@JPhi1618 agreed - it would be unpleasant to say the least, which further reinforces my recommendation for a centralised system.

I'll address some points from Zhaph - Ben Duguid's answer:

While you could indeed manage the project with a tool like GitHub (using the Issues feature), you might be better off initially managing the tasks through a tool like Trello which allows you to create tasks and move them through various status (i.e. Planned, In Progress, Review, Complete) in a fairly simple, intuitive user interface.

Github actually has this as well in the form of Project Boards. They integrate with the rest of the GitHub ecosystem, so you can reference issues, pull requests, assign milestones and labels, etc.

Git is a "Distributed Version Control System", which means that anyone can work on any file in the repository on their local machine - this is usually fine when working with text based files, but is not so good when you have binary files, because understanding the differences between two versions is often not easy.

This was a painful point for a long while. However, git now supports Large File Storage. It stores references to the files, so checking changes between commits would show that a file was updated and not waste space trying to calculate diffs. I have used this for images and other binary files and it works well, though it does add a small extra step to upload or download the files when pushing or pulling.
You could easily use LFS for the various binary files the programs use for creating.
Edit: File locking

I would strongly recommend that you consider a Centralised Version Control System such as Subversion (SVN) or Team Foundation Version Control (TFVC or TFS) as this allows your collaborators to "checkout" or "lock" a specific file to say they are working on it, and then when they've updated it, "check-in" their changes - this will (hopefully) get around the main pain points of trying to merge changes in these files, albeit with the caveat that you might still have people check-out a file and then "go dark" and forget to check it back in for a long time.

Git LFS also has file locking (Since 2.0, March 2017). I do agree that it is more complicated than SVN. I do not know if the web platforms or desktop apps (GitHub Desktop) show locks, but I do know that you can lock and manage locks via the command line:
git lfs lock file.ext    # lock file
git lfs locks            # show locked files
git lfs unlock file.ext  # unlock file

You can enable locking for an extension across a repo by adding *.[extension] lockable to your .gitattributes file, and if a user has locked a file and disappeared someone with the proper permissions can unlock the file with git lfs unlock file.ext --force.

Good point on the GitHub's boards and integrations, however that might still be overkill for the project, and more confusing, especially if most of the contributors aren't used to all that ceremony. I also agree that LFS is a possible option, but that's more to work around the file size limits (100MB) and performance impact of working with those files. You'll still be unable to review any changes to binary files in any meaningful way. Hence my suggestion of a centralised system that allows users to lock the file centrally to say "I'm working on this" and (generally) avoid these issues.

@Zhaph-BenDuguid I'm not sure how GitHub's projects would be confusing, since you can use it exactly like Trello if you want. I do agree that locking is the better method for editing binary files, git LFS even supports locking files!

I meant that throwing in references to pull requests and milestones might be confusing ;). Good to know about locking in LFS - feel free to update your answer with the steps required to enable that for .io files across all instances of the repo and the on going use, it's more complicated than SVN or TFS if you've got to fetch and then lock, and remember to unlock after a push... As is the nature of open-source, who knows if the 2.5 year old documentation is out of date, or whether LFS 2.9.1 has a less "early release" version of locking?

@Zhaph-BenDuguid Good point about updating my answer, done! It does seem more complicated than SVN and I haven't been able to find if it is supported in the various web interfaces, but it seems like a handful of the most popular git platforms do support the feature. I also haven't found anything else about updates to the locking, so it might have been "good enough" in 2017 and hasn't needed any more attention since then.


text:
Use D output in 42099 (4X4 X-treme Off-Roader) set
How I can use the D output for an additional motor in the 42099 set? Or how can I use a custom control skin?

At the time of writing this, it is not possible to use the Control+ hub and motors in any other configuration than the already existing preset ones. This situation is expected to change, but there are no promises regarding functionality or timeline from LEGO.

source: Stack Exchange

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

sort: votes


text:
My Mindstorms Spik3r can't turn around
When I use the button for turning it just goes backwards. Why does this happen? I've checked the instructions and didn't find anything.

Thank you but I'm sorry I've didn't sad it correctly. It works once but when it goes forward it just ruins the wheel and then. It is not working.

What do you mean by "ruins the wheel" and "It is not working"? Could you please post images, videos or detailed descriptions of the encountered situation?

I've „meant ruins the position of the wheel and it's tilt" so it can't turn.

I have updated my answer below, check if any of that helps.

According to this article, the turning is supposed to function via a

wheel on the bottom that while the car moves forward stays straight but that once the car moves backward moves a little to the side and forces the car to turn.

If correctly built, it should look like this:

A bit later the article offers a few tips on troubleshooting, among which there is your issue as well:

Problem: My Spik3r doesn’t turn
This looks like a construction problem. Check the above photo to see how the flying wheel is supposed to look like.

Edit after an update to the question
The wheel marked with the red free-hand circle is meant to slide freely in forward motion (the head of Spik3r is seen at the bottom of the picture), as it is pivoting around the axle with the yellow half-bushes, and get stuck in reverse (as the blue pin catches on the black undercarriage), thereby braking that side of the Spik3r and causing the model to turn towards that side.

If this wheel gets stuck during reverse, then it is working as intended and should provide enough friction to turn the whole model.
If it does not get stuck, then it is due to a mistake in the build.
If it gets stuck but does not force the model to turn, then you might need to change the friction between the wheel and the ground it's running on (e.g. use it on a carpet or any other surface rougher than the polished hardwood shown in the background).

@Deatroyer You're welcome! Feel free to read the [tour] and the [help] pages, and don't forget to click the checkmark icon to show that the answer has helped to solve your issue.

Thank you but I'm sorry I've didn't sad it correctly it works once but when it goes forward it just ruins the wheel and then! It is not working

@Deatroyer Wdym "ruins the wheel"?

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


text:
Any idea what this part is?
I have bought a mixed bag, with not many booklets. This LEGO part has no part number, I'm trying to find it's set number.

This should be this part Windscreen 8 x 6 x 2 Curved
which appeared only in one set wit those stickers: Separatist Shuttle 8036

The middle decal seems to be backward between this and the OP's piece...

@DarrelHoffman presumably it was applied incorrectly?


text:
Which set did this assembly came from?
Does anyone know which set did this came from? I got a bundle without instructions, some of it's partially built. I have no idea how to finish it for my kids.

Hi Pavel and welcome to Bricks.SE! Rin Rio-Oki has already answered the first question ("Does anyone know which set did this came from?"), to the second ("I have no idea how to finish it for my kids.") I'd recommend giving this and the entire lot to the kids and let them finish / alter / disassemble it as they see fit. Quite possibly they will end up having a lot more fun than if you handed them a completed official set.

Looks like a custom build, so no instructions.
I'm basing this answer off two parts in the pic:

Part #6046 - Brown Bar 9 x 13 Grille, appears in six sets with this color, and none of the sets seem to have a sub-build of this prison.

and

Part #2431px5 - Tile 1 x 4 with 'KEEP OUT' Pattern, appears in three sets with none of them resembling a hidden sub-build of this cage design.

Also, not really lego quality build, too random

Thank you. It is likely the person I got the lot from from built it himself. I was just wondering as I wanted to complete it for my kids. THANK YOU !

@Pavel You can accept this answer as a great way to say thank you also.

@Pavel, You're welcome!


text:
EV3 program runs fine when connected to PC but does not respond when copied to the brick
I am building the race car mentioned in the LEGO Mindstorms discovery book using an EV3 brick.
The problem I am facing is that the driving program runs fine when the brick is connected to the PC via USB. I can run it, I can use the remote control and test the car to steer, move back and forward as long as I like.
However, once I transfer the program to the brick, and run it without PC, it responds to the remote only twice and then stops responding.
This is very weird because if there was a problem in the program, it should not run in the first place even from PC directly, right?
So I guess there is something wrong in my program when it gets transferred to the brick.

Hi and welcome to Bricks.SE! Just to be clear, have you checked for the usual suspects, like loose cables, near-empty batteries, etc? By "stops responding" do you mean there are no outputs at all, for any combination of inputs? Does the EV3 respond to pressing its own buttons, as opposed to those of the remote? Is the "only twice" part reliably repeatable, or is it "usually twice, but sometimes once or thrice"? What do you do that enables the next two responses? Can you test a program that waits for a remote button press and in response turns a motor and increases a number on the display?

The difference between being connected to the PC and not is that the PC is constantly polling the EV3 for sensor values when it is connected, so it does change the timing of the program. Although I would not expect it to make a program "get stuck".

Thanks for the comments. I figured it out and the mistake was simple. I had two separate and independent program sequences each with its own start point in one program window. One sequence was for testing purpose to see if everything works and
 the 2nd sequence was the actual driving block. As I am new to this setup, I guess one window should have just one program sequence.
Once I deleted the test block and kept only the driving sequence, everything works fine. Posting this just in case some newbie might find it helpful in future.
For the veterans, I hope my understanding is correct that in one window, there should be only one start point.


text:
Can you identify if this part is original?
Recently, I bought a LEGO part from Bricklink (Technic, Steering Arm with 4 Ball Joints with Black Wheel Hub (x872 / x873)).
I'm not sure if it is an original part or not, because I don't see any LEGO trademark or ID number on the element and I cannot find any reference for that part. The only text on the brick is a single digit (e.g. "7").
Quality of the item is really good, so I believe it's original, but I need to be sure.

I've added the Clone-Brands tag off of the OP's suspicion of "doppelgangery", not that this piece has been proven to be cloned or not.

I got such pieces from sealed set (long time ago though) and none of these parts have any sort of LEGO brand identification.
So it could be legit part after all.


text:
Identification of blue and black tower
Can someone help we with identifying this set?

Not going to bother to search as this is again clearly not part of any official LEGO set as it is too amateurishly designed.

The list of sets containing Black Brick, Arch 1 x 5 x 4

(or its alternate version) and the list of sets containing Blue Slope 33 2 x 2 Double

has no common element, therefore these parts have never appeared together in an official set, so this must be a custom creation.

Thank you for your answer. I am impressed - can I ask how do you even know these 2 pieces were never together ? Is there some search engine or does it come from experience ? Thanks again and have a nice day

@Pavel The links in the answer point to the Bricklink queries listing all official sets the parts have ever appeared in. Then by comparing the two lists one can see there is no common element. So yes, there is the Bricklink search engine, additionally Brickset.com has comparable functionality as well.


text:
Bag #3, no instructions, no box
I bought a box of LEGO bricks at a flea market. This bag came in it and we want to figure out what it is. The polybag says "3" and the number on it is 135149 but that’s all I have.

Hi Emilee and welcome to Bricks.SE! Please don't add "thank you" as a comment, instead click the checkmark icon by the answer to indicate you are satisfied with it. Also see the [help] and [tour] pages to learn more about the site and our community!

I think that is 7937 "Train Station"
Method:

I recognised the white girder piece as being in the Saturn V set
Bricklink then shows all other sets with that piece
Of the eight sets that have that piece in white, the 7937 also has two blue chairs and some grey ladders.


text:
Anyone know the identity of this set?
Came in a single unnumbered bag with standard 2011 markings.

Based on the Tan Window 1 x 2 x 2 2/3 with Rounded Top
and the 4 Red Brick, Modified 1 x 2 x 1 1/3 with Curved Top
This is from 10696-1: Medium Creative Brick Box


text:
Does anyone know what set this is?
I have recently re-discovered Lego and was looking through my son's old sets. In a box I found this partially assembled "Bug". I don't have the instructions nor the original box so I am unsure what set this is.
If I can figure it out I can get the parts list and instructions and complete it.

Could you post a bigger picture?

I believe this to be part of the Insectoid space series,
I think set 6907:

https://www.bricklink.com/v2/catalog/catalogitem.page?S=6907-1
But could also be one of the other 3 sets that contain the stinger.
https://www.bricklink.com/catalogItemIn.asp?P=x239&in=S

Michael, I believe you are correct...I think it is the set # 6969....I will check more thoroughly tonight. Thanks for taking the time to answer my question. It is greatly appreciated!

Based on the wings, the magnet on the tail and the legs it must be 6907 indeed.

Yes, the 6969 has larger legs and only two


text:
How to make Spik3r move without the pincers moving
How do you make Spik3r move without the pincers moving as well? Seems like the legs are only controlled by the motor on port B, but the move tank and steer modules only allow for the use of 2 ports. Using ports B and C (vacant) results in an error, while there appears to be no way to tell the motor on port A (pincers) to not to move when ports A & B are selected.

Don't use the Move Tank or Move Steer blocks. Use the Large Motor block for controlling a single motor instead.


text:
Can you tell me what Star Wars vehicle these are from?

Not sure what those round grey parts are. They have a blue "light" on them. My son has almost exclusively Star Wars sets but we can’t figure out what these are from.

Welcome to Bricks.SE, Laura! These pieces are not very rare, and hence finding the set they come from is going to be pretty hard. With your hint that your son only has Star Wars sets, I think this is from 75166 First Order Transport Speeder Battle Pack, where these parts form the engine outlets of the small vehicle.

I have this set, and my initial thought was this one too. Does he have a few extra gray lightsaber hilts? The rest of the engines in question are the same part as the lightsaber hilt, except in a color not usually used for actual lightsabers. Also look and see if he has the riot shields from this set, as they are pretty uncommon in this print.


text:
Can 2 baseplates be connected to make 2 story level?
My young girls are creating a house and want to connect baseplates to make a 2-story house. Is there a way? Are there specific pieces that can connect them?

Perhaps this question and answer can help you: https://bricks.stackexchange.com/questions/7367/is-there-a-baseplate-with-connections-on-the-bottom

Wdym? Do you mean that one baseplate is for the second floor while the other one is meant for the first? If so, you might see that you won't be able to build a way to get to the next floor (i.e. stairs or ladder). In this case, you should add another slim baseplate next to the first floor's baseplate and build the stairs or ladder on it to reach the next floor. But youll need some floor there, too. Just remember to make a hole so that they could get to the second floor! Oh, and obviously  you'll need some bricks to build the walls on the first floor, then you can attach the second floor on top

As Michael mentions, the following answer is probably the one you want: A baseplate does not have connectors on the bottom

Well, only SOME baseplates don't have connectors on the bottom. It really depends on the size.

@mindstormsboi Can you name any that have connectors on the bottom? I think that's part of the definition. Ones that have connectors are known as plates.

They are quite small compared to the ones that don't have connectors on the bottom. Some are 4 by 4, 5 by 13, 4 by 11, y'know.


text:
Which set does this flywheel-like assembly belong to?
Please help me identify the set this part belongs to.

This assembly consist of two parts. Well, technically, four parts, as there are two Technic 2L pins in Black, but these come in multiple sets so out of interest.
Top one in Orange is Flywheel Fairing Lion Shape with Gold and Blue Feathers Pattern (70102)

And the bottom one is Flywheel Plate 2 x 8 with Metal Flywheel and Dark Azure Tire (Chima Rip Cord Base)

Top part was available only in 70102, CHI Waterfall set. And the bottom one was included in 22 sets.

What an odd set, I thought it would be part of some exotic motorcycle but this is more obscure.

@Mast Arguably a drunken, anthropomorphic lion riding a rocket-powered ripcord unicycle with a golden-feathered lion fairing in a jungle is the most exotic motorcycle concept ever.


text:
Container part identification
Please help me identify the set this part belongs to, we are going through three tons of bricks and try to put the sets together again...

That looks like Container, X-Pod Barrel Section 10 x 10 x 3 1/3, which were used to store bricks for X-Pod sets.

Such container was available in Trans-Red in single set 4415, Auto Pod

And 4417, Aero Pod was the only set to use it Trans-Yellow

Great picture choices help make this a really good answer.


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

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


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

Digging a bit into the C source code for the pybricks firmware, I was able to find these two lines:
PT_SPAWN(pt, &child, lsm6ds3tr_c_xl_data_rate_set(&child, ctx, LSM6DS3TR_C_XL_ODR_833Hz));
PT_SPAWN(pt, &child, lsm6ds3tr_c_gy_data_rate_set(&child, ctx, LSM6DS3TR_C_GY_ODR_833Hz));

...which means that the IMU is set to a sampling rate of 833Hz.
Please note that this is how the IMU electronics are configured when pybricks starts - this does not necessarily mean that the pybricks firmware nor the hub's microcontroller CPU can keep up with that rate, or that they can run some of your python code 833 times per second, or that pybricks will run python code at that rate.
It should be possible to change the sampling rate by modifying the pybricks C code and recompiling the firmware. If you want/need to take on this endeavour, read https://github.com/pybricks/pybricks-micropython#development first.

In the comments of one of the accepted answer on the question here:
What internal electronics do Spike Prime and Mindstorms Robot Inventor use?
it's mentioned that the pybricks people have determined that the IMU module is a STMicroelectronics LSM6DS3TR-C.
Googling for this I found the following document on the manufacturers website: https://www.st.com/resource/en/datasheet/lsm6ds3tr-c.pdf
Which list output data rates from 1.6 Hz to 6.6kHz, probably depending on which mode the chip is configured in... I have no way off knowing which mode/value applies, but perhaps someone else does...


text:
What sets are in these mixed bags?
I don't have the instructions nor the original box so I am unsure what set these are. Does anyone know what are the names of these Lego sets? Where to find the instructions?
1

2

3

4

5

6

7

Apparently you have a large amount of sets from different themes and eras mixed thoroughly, which only allows the identification of a few sets that have quite distinct pieces. You could pick out the pieces for those sets and try to identify the remaining heap starting by the most unusual pieces.
For instructions I'd recommend checking Brickset. For example if you need the documents for 3847: Magma Monster, you'd look up that set and find the instructions below the main image.

Now, for your photos:
The balloon tires in the first image are called Tire 81.6 x 38 R Balloon, available in 16 sets. The thinner tire is called Tire 94.2mm D. x 22mm Motorcycle Racing Tread, available in 8 sets. The Orange Dish 8 x 8, as identified by Phil B., appeared in 3 SpongeBob sets from 2006 and a city set from 2010, besides an obscure FIRST LEGO League set.
The baseplate in image #2 is Baseplate, Raised 32 x 48 x 6 with Level Front, contained in 3 sets in gray and two in tan (presumably the one under it has the same pattern).
The wings in the third image are Wing Plate 20 x 56 with 6 x 10 Cutout and No Holes in dark bluish gray, these are definitely from 7683 - Fight on the Flying Wing.
The orange baseplate in image #5 is Orange Baseplate 16 x 16, from 3847 - Magma Monster.
Images #4, #5,  #6 and #7 depict seemingly unopened bags, which would mean their contents belong to a single set.
The top bag of #6 has Technic Engine Cylinder with Side Slots (2850a), Technic, Liftarm, Modified Bent Thick 1 x 11.5 Double (32009) and Technic, Gear 40 Tooth (3649), which together with the red fairing have only appeared in 8051 Motorbike.
Bag #1 here seems to be from 8088: ARC-170 Starfighter, as the Dark Green Brick, Round 2 x 2 Dome Top with Pearl Dark Gray Pattern (R4-P44) only appears in that single set.
Image #6 bag #2 has both Dark Tan Wheel 31mm D. x 15mm Technic and a Light Bluish Gray Technic, Brick 1 x 14 with Holes, together only ever released in 8096: Emperor Palpatine's Shuttle.
Bag #3 of Image #6 seems to be from 7930: Bounty Hunter Assault Gunship based on the Dark Bluish Gray Technic, Axle 8L with Stop, Dark Bluish Gray Plate, Round 4 x 4 with Hole, Dark Bluish Gray Wheel 31mm D. x 15mm Technic, Yellow Cylinder 4 x 4 x 1 2/3 with Pin Holes and Center Bar and Dark Green Cylinder Half 2 x 4 x 5 with 1 x 2 Cutout.
On the bottom left, bag #4 has a Light Bluish Gray Technic, Axle Connector Hub with 3 Axles, a White Plate 4 x 6 and most importantly one White Tile 2 x 2 with Groove with Ninjago Cracked Red Skull on Black Circle Pattern, which only appear together in 2506: Skull Truck.
The packages in image #7 are way too hard to identify, since they are not laid out neatly as in #6, so partially overlap each other and the loose parts underneath them, so please upload a separate image in the style of #6 if your own efforts remain unsuccessful.

That 3961 Dish 8x8 in Orange is in 5 sets, including 3 from the Spongebob series.


text:
Trading and Lego VIP
What websites can be used for trading? I want to  have as many rare ones without buying anything. Does someone want to trade a Lego minifigure for free? I have been trying to get many Lego minifigures for a stop-motion movie.
Finally, how do I get all my free stuff from Lego VIP without buying anything?

hello! if  you have  been to the lego website, there is a new thing called lego vip. if you signed in your account and sign up for the vip there is some cool rewards about it.

The go-to sites regarding LEGO brick trading are bricklink.com and brickowl.com. They operate as marketplaces where people can buy and sell sets, parts and minifigs alike. There is one site I've found that is marketed as a dedicated place to trade (or in other words swap) minifigures: swapfig.com - Note that there is not much experience with this platform, so exercise caution when operating there.
Regarding the "Finally" part: I don't know of any such opportunities, could you please clarify what have you heard/read and where?

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


text:
Instructions for these two LEGO bags?
Looking for some help. Christmas morning was a blur, and we ended up with two LEGO bags with no matching instructions. Can you all help identify the contents and correlating instructions?

that's is from set set 11018-1

Both bags appear to be from set 11018 - Creative Ocean Fun

Building instructions are available from Lego customer service here.


text:
What is the axle length of this?
What are the lengths of the bottom axles on this picture? Like 5L

That's quite a bad picture. I'm not even sure what belongs to the assembly that you're talking about the bottom of, so I have no idea how to help you.

To find the length of an axle, you can just hold it next to a regular lego brick or plate, and count the studs. If the axle is as long as 5 studs, it's a 5L axle.

I have updated the picture so it is more clear

which video are using?

delayed, I'm sorry for that video

It's running through 2 33299 Technic Crank pieces and is as wide as the pins of 2 crank pieces side-by-side.

That would make it a 4L axle which typically are black.


text:
Does anyone know what is this LEGO Mursten set?

I'm having a hard time identifying what set this is. I want to sell it but I don't know how to name it.

It's apparently LEGO Mursten 700/6 Gift Package, specifically the first variant from 1953-1954.

Early versions of this set from 1953 through 1954 had only automatic binding bricks type windows and doors without glass. In 1954 they were replaced by tall classic windows and doors with glass. From 1956 to 1965, the set had only the classic type of windows and doors.

It appears it is listed as 700.6-1 Gift Package (Lego Mursten) on BrickLink, however the inventory appears to be of later versions of the set with newer windows.
Figuring out what it might be worth is likely going to be very difficult. There aren't may similar sets listed or sold on BrickLink. What you have appears to be fairly rare, but it may be the kind of rare that nobody really knows about to look for and buy.


text:
Lego China Cabinet
I'm building a Lego china cabinet and I'm looking for some nice pieces to put in it. (Fancy dishes, table settings etc). Here's a picture of what I have so far:

Here's some pieces I've identified in my want list so far:

dragon bowl
Minifigure, Utensil Bowl with Gold Rim and Stripe Pattern
Minifigure, Utensil Bowl with White Rim and Waves Pattern
Glass for Window 1 x 2 x 2 Flat Front with Ornamented Window Arch Pattern
Minifigure, Utensil Sun Disk
And of course the usual goblets and wine bottles.

Can you suggest any other nice pieces that would go well in this build?

How about tea cups with saucer? That’s a recent mould that should be easy to get

There are some nice tea bowls in the Tranquil Garden Set. You could also appropriate some pieces as figurines, such as the famous frog in a pretty color, or some of the tiny flower combinations. My grandmother used to keep such china figurines in her cabinet.

You could go macabre, and source a pirate skull, or a ninjago villain such as this snake head
http://76.my/Malaysia/lego-ninjago-snake-villain-spitta-minifigure-newl-yesbrick-1307-08-yesbrick@1.jpg

Make it a gruesome trophy case huh?  I would but this is a christmas gift so I think I'm looking for a more traditional look


text:
Need help identifying two unopened bags of Lego
We were cleaning out a drawer in my son’s room, and we found two unopened bags of Lego. We don’t know what sets they are from. Bag 2 has a brown oar and a black bat (like the animal)in it. Can anyone help us figure it out? Thank you so much!

Does this answer your question? How can I identify a set based on one or more original sealed bags?

Based on the parts
Black Bar 1.2L with Top Stud and 4 Bar Arms Up (Palm Tree Top)
and
Light Bluish Gray Wedge 4 x 4 (Slope 18 Corner)
these bags can only come from
40597 Scary Pirate Island


text:
How to fix this Error in EV3 Classroom?
So I got the error "Heads up! Couldn't open this project" and did research and found out that it is a generic error, then looked up the exact error on this site: https://legoapptools.azurewebsites.net it showed me this error:
#WARNLONESTK1 Lonely stack ev3move_rotation-wheel()
#WARNLONESTK1 Lonely stack procedures_call()
#WARNLONESTK1 Lonely stack ev3sound_playSoundUntilDone()

I understand that the problem is that I have Blocks floating in my project, but I don't know how to fix it. Here is a link to the project file: https://www.dropbox.com/scl/fi/aqsg90fv7mptqmi1o5zhc/WRO2024-1.lmsp?rlkey=nd6j1b8dlcrt45iadyqy5ri2d&dl=0

The Lonely stack is not an error. This particular file contains a null value in a list which isn't valid. I updated my answer at https://bricks.stackexchange.com/a/16945/3498 to describe how to fix this.

Here is a link to the repaired file WRO2024 1 - fixed.lmsp.

@DavidLechner thank you very much I saw you're answer to the other post but I couldn’t solve it on my own. You are a life saver! I hope they will add an easier solution to this. Greetings Jonathan


text:
How do I get a variable and image into the Lego Mindstorms EV3 image editor
I am making a project and I want the EV3 brick to have a GUI-like interface. It also needs to display a variable on the GUI. Is there a way to draw the GUI and have the live variable reading as well? The image text block just replaces the whole image. I would like to do this without drawing out a state for every single possible variable value and then updating it to match the variable.

Can you share a screenshot of the program that you tried that does not work?


text:
Has anyone had problems fitting the stalactites and stalagmites in the 76252 Lego Batcave?
I have got to stage 403 and, whilst I have had problems fitting the pieces together previously, at this stage I simply cannot get the stalactites or stalagmites to fit into the studs - they seem to have a bulbous end and they simply will not fit. Is glue the answer? Has anyone else had the problem?

I guess you have a question regarding 76252 set? Glue is NEVER an answer for official LEGO set. It would also help if you added a picture of your assembly at a location you are having issue with.

Step 403 of the instructions for set 76252 - Batcave - Shadow Box constructs two stalactites like follows, so I'll assume that's the set you're talking about :

Given your description of what doesn't work for you, the only thing I can think of is that you're trying to insert the 1x1 round stud with hole (the middle part in the assembly) upside down. Look closely at the image, and make sure it's the right side up, and it should fit just fine.

No I am definitely trying to insert it at the right end !

@MikeP : then it should fit as shown. Can you clarify what you mean by "a bulbous end" ? Maybe add a photo to your question ?


text:
Cat D11 calibration starts then stalls
My Cat D11 lego worked perfectly a few months then it stopped having full range of movements (blade, rear ripper, stairs) but still drives ok. When I try to calibrate, it starts the process but then it stops and nothing happens (no gearbox sound or movement). Any idea what to check/do?

Does this sound like the same issue you are having? https://bricks.stackexchange.com/questions/18325/calibration-freeze-on-d11

Yes very similar thanks!


text:
In what set does this purplish star-stickered part belong?
Hello I need to identify this piece. In which set is it related too.

It seems like it's a medium lavender 2x4 tile from 41055 - Cinderella's Romantic Castle, based on this sticker sheet found on Rebrickable:

It is used to represent a bed/sofa there:


text:
LEGO Studios Movie Maker Camera (1349) (2000)
A few months back I had purchased the LEGO Studios Movie Maker Set (1349) and have been tampering with it, specifically the camera, to see if I can get it to work on my Windows 11 laptop. Was able to download the software off of Internet Archive, yet whenever I plug the camera in it does not respond. My laptop recognizes when the USB is plugged in, yet the movie maker software does not. From what I have noticed it could be the drivers, as whenever I try to update them using Device Manager it seems to not work, assuming it is because how old the camera is. The software itself works perfectly fine; it is just the camera that cannot be recognized on the software. If anyone knows how to solve this issue or has any tips, please let me know!

Do the answers in LEGO STUDIOS Moviemaker Set help you out ? It sounds like it's not trivial trying to get the drivers to work on a modern Windows version. Maybe a virtual machine with either Windows XP or 98 will get you further ?

Hi, the manual included with the set does not really help me with anything. The drivers within the camera seem to be missing whenever I look up the connection within Devic Manager. Have thought about downloading a version of Win XP or 98 on my Win 11 laptop to see if I could get the camera working from there, but I am not 100% sure where to look.


text:
Is it possible to connect a motor to a spike hub without connecting the cables?
I know it sounds foolish but can I?
I've tried Robot Inventor, but it just doesn't connect and doesn't work.

Hi cnvıkyghb and welcome to Bricks.SE! Please note that this is a Q&A site, where volunteer participants take their time to share their knowledge with askers, since they believe in the value of sharing and helping. Please show your respect to these people and this idea by taking your time to properly spell and format your messages here, if you wish to participate in this community. If you plan on staying, I'd recommend that you read the [tour] and [help] pages to get acquainted. Have fun!

Definitely not. Without cables, no electric current can flow so the motors would not be powered. Wireless power transmission at such wattage levels is not yet part of LEGO's technology stack and probably won't be for a long time. Wireless control would be possible though, but that would still necessitate some kind of power supply at the motors (batteries, mains converter, or such).


text:
What set do these four bags belong to?

Found these four sealed bags. Any idea what set they go to?

I've got a few parts leading to this query leading to 4 sets. I'm thinking this is a millenium falcon but cannot be 100% sure.

Does this answer your question? How can I identify a set based on one or more original sealed bags?

@LKBricks you can clearly see an experienced member of this community is struggling to identify the set. What kind of outcome do you expect OP (a new (!) contributor) would be able to get out of the linked article?

Starting with IvanSanchez's search (sets with at least two of trans-red projectile 8L, two of dark bley 4x6 plate w/ door hinge, two of light bley 3x12 wing/wedge), this is probably the 2019 millenium falcon 75257
If you look correctly bag 7 contains C3PO and in bag 8 is a R2D2 body.
When going through the instruction of this set you see C3PO is in bag 7 and R2D2 is in bag 8

So that's what the golden bits in bag 7 were. Good eye!

I only recognized it when going through the instructions. Was more focused on finding the red part in bag 8 in the instructions


text:
Bag Identification: Bag 5 Possible Alien kit
We have an unidentified bag #5. It matches the color palette from Space Mission 11022 bag 5: Black, Magenta, Grey, Purple, Neon Yellow.
Distinct pieces include 4 silver grey ray guns, 4 silver grey chalets, 5 purple bionicles.

Please add a photo of your bag and its contents.

Hi Meagan and welcome to Bricks.SE! I took the liberty to edit your post to better fit the site's rules and customs, but I can't figure out what you meant by "chalet" - surely not the Alpine lodging. Similarly, there are hundreds of Bionicle pieces so that's not something one can use to identify your set. I can only second Alex's request for a photo, where the individual pieces are clearly visible (take care with focusing, lighting and resolution). Meanwhile, feel free to take the [tour] and read the [help] pages to learn more about the site and how things are done here. Have fun!

Going out on a limb here, but can it be that your bag is indeed THE #5 bag from Space Mission 11022? It ticks off all boxes:

Matches the color palette of bag #5 from Space Mission 11022 (obviously):

Has exactly four of Minifigure, Weapon Space Ray Gun - Rounded Heat Diffusers in flat silver:

Has four Minifigure, Utensil Goblet pieces in flat silver (the words "chalet" and "goblet" do sound quite similarly):

Has four plus one spare, so five purple Barb / Claw / Horn / Tooth - Medium pieces, which (in various colors) have indeed appeared in 24 Bionicle sets:

This was our original thought as well. However, we completed all builds and were left with a significant amount. None of the items like the goblet were referenced. We wanted to make sure we didn't miss a build. It looks like these are for create your own. Appreciate your response.

@Meagan "we completed all builds and were left with a significant amount"
That's entirely intentional - see this excerpt of the official product description:
"Includes everything kids need to create 10 space-themed toys, plus lots of LEGO® bricks for free-build space creations". Have fun with all the creative possibilities :)


text:
How can I remove a Lego 4x4 plate from a non-Lego baseplate?
I have tried using a brick separator, prying with fingers, bending the plate and stacking bricks on it.

Hi @CluelessLegoenthusiastically and welcome to Bricks.SE! If you can, please upload a picture so we can see what sort of baseplate you're faced with - the type, thickness and positioning might all offer possible solutions. Meanwhile check out the [tour] and [help] pages to learn more about the community, its rules and customs here. Play well!

Have you tried combining the already tried approaches? For example, adding some 2x4 bricks on the plate to act as a lever (in the direction of the longer side of the 2x4s), then bend the plate and the baseplate in different directions and slip the edge of a brick separator in the (hopefully) revealed space between the plate and baseplate.


text:
Help identifying set just with a bag of common bricks
I have a picture of this bag with LEGO bricks in it. Any idea what set this is?

Does this answer your question? How can I identify LEGO sets from a box or bag of parts?

Or this? How can I identify a set based on one or more original sealed bags?

❤trying to solve this for my patient. Definitely not a Lego aficionado

Do you have a larger picture? There seems to be a lot of common parts, so it isn't easy to identify anything reasonable at this scale.

Based on the 6 x 12 tan plate and some of the other more basic elements, this appears to be a bag from Bricks and Houses (11008):

If this is the only bag you have, it isn't a complete set and you likely can't build any of the models from the instructions. This set is an assortment of basic elements, so you could still get some good free building value out of the parts you have.


text:
Please help me identify unknown bag of lego
I got a bag of LEGO bricks at our local share shed with the number 4 on it. A QR-code on the bag encodes the number 6172089. The bag says 2017.
Pieces are all khaki tones, tan, beige, sage green, brown. There is a large circular time piece and what looks like gear pieces.

Are you sure you don't want to upload a picture? Are you sure you don't want to use the search?

Hi Katy and welcome to Bricks.SE! As you can see, we already feature a guide on identifying sets based on sealed bags. Please give that process a try and let us know if you have any issues while doing so. We'd love to hear your feedback and could help both you and anybody else with the same problem later on.


text:
Looking for instructions to a set with many different sized round cogwheels
This bag came in a large box but the bags didn’t have identifiers ie: 1,2,3 and we lost the instructions. Two small bags came inside the larger bag.

This is set 11019-1 Bricks and Functions

Key parts:
14t plate gear (35446) in Lime
Turntable Base (61485) in White
and a 1x4 gear rack (3743 or 4296) in White


text:
How do you open this thing without damaging it?
It's a 9008 DUPLO Activity Set from 1986. Looks like this on all the boxes.

Hi Beate and welcome to Bricks.SE! Have you tried pushing in the three tabs on the underside of the brick with a suitably sized flat-head screwdriver while prying the cover with a flat tool? Since the three tabs seem to hold the back plate simultaneously, you might need to depress all three at once, so borrow a pair of hands if possible.

I haven't! Was afraid it might damage it. Thought there might be some special tools of some sort. But I think I'll try on one of them, and get back to you with the results!

It's definitely not designed to be opened once assembled, but nonetheless it might be doable. Take it slow and be careful, but also keep in mind that ABS can easily be glued even if it breaks. And if you can manage it, please take photos of the process - so that you can contribute the answer for the benefit of future readers :)

We tried but wasn't able to pry it open :(


text:
What brand of non-Lego bricks are these with hollow studs and diagonal walls on their undersides?
Believe they are from the 1960’s, available in Australia.

I find the article Bricks on Display: a collection of interlocking building bricks on brickset to be a good source of information for this kind of question.
These appear to be Montini bricks (made by Berco Lux in Tiel, Holland, in the 1960s, as a clone of the early Lego Mursten) :

(images are from that same article)
The name of the brand should be engraved on the surface somewhere (between the studs afaict) - can you find it ?

1st guess Montini, made in The Netherlands, but mine had name atop.
Do 2×x have pegs to fit hollow studs? Made of softer plastic than Lego is.


text:
Cat D11 bulldozer - should the plough and the frame be connected?
I’ve completed this and now have some remedial work to do! Can I please check though, are the two parts at the back (the ‘plough’ and the ‘frame’ with the ‘pistons’ on) supposed to be connected in any way? I haven’t connected them but it seems like they should be.

Step 925 indicates there are four attachment points for the plow. I'd suggest checking your model against this, making sure each point lines up.

Thank you. I ended up rebuilding. I'd put two L shaped pieces on pointing down rather than up hence I couldn't link the back parts up properly. All good now :-)


text:
Are there LEGO pieces without "LEGO" logo?
I have a LEGO wizard, the green one with a wizard hat that has a dragon on it but the hat doesn't have a "LEGO" logo on it. Also the beard. But the rest of the torso and legs have markings on them. Are the hat and beard fake?

Is this a question about specific items you have mentioned or you'd want to know which LEGO elements have no marking on them?

Welcome to Bricks.SE.  A more general discussion of this question can be found at https://bricks.stackexchange.com/questions/15101/which-parts-do-not-have-the-lego-logo-stamped-on-them .

Does this answer your question? How do I identify a LEGO part?

Does this answer your question? Which parts do not have the LEGO logo stamped on them?

Some Lego parts don't have a logo on them, depending on the mold.
Like the helmet in this question
Need help identifying helmet
your figure is probably this
Part 6131pb03 : Minifigure, Headgear Hat, Wizard / Witch with Black Buckle and Gold Dragon Pattern

from
cas435 - Dark Green Wizard


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

Hi Ken, welcome to Bricks SE! We will find your question a whole lot easier to answer if you include more information about what you are building, and if possible a photo (or rendering) of what you have so far.

maybe the parts 73763 and 73764 will help?

What should be the range of vertical motion? How far should it be able to rotate (maybe unlimited)? Should the rotation and movement be coupled as to happen at the same time or should they be independent? How big should / can the platform be?

They are many ways for a "Lift and Rotate" platform.
The easiest way to do this is by using the rotary part 73763 (Technic, Gear Worm Screw 6L) and the stationary part 73764 (its housing), and a Technic Small Linear Actuator on the bottom that stays in the fixed rotation.
The second alternative is to use gear racks and bevel gears for the same effect.


text:
Is there any way to unzip an ev3 file into text and xml files?
I would like to access the text file of the project files (.ev3p) to know their structure. But in the Mindstorms software, I couldn't find any way to download the .ev3p files.

Hi theboguz and welcome to Bricks.SE! It seems there is a significant disconnect between the question title and body - do you wish to download an .ev3p file or unzip an .ev3 file?

Sorry, @zovits! I would like to unzip an .ev3 file into other files. Thanks in advance.

Does this answer your question? Export LEGO MINDSTORMS EV3 Lab Code

As several previous answers on this  stack exchange site have already clarified, an ev3 file is a .zip file. Rename it and change the extension to .zip and you'll be able to open it. What's inside it is documented here: https://afarago.github.io/EV3TreeVisualizerPages/filesyntax.html


text:
Looking for instructions to a set which contains bags that have the number 135149 on them
The box is lost. The QR code doesn't work.
I have tried looking up some random pieces online, but can't find them.
It's not the helicopter set. It seems 135149 appears on many bags.
Contains red and yellow flowers, and eyes.
3 bags with mostly red, yellow, and brown pieces.

Also providing a couple of picture will help us to help you ;)


text:
Windows XP (VM) problem with Mindstorms IR USB tower
So, recently I tried to make my old Lego Mindstorms (RCX) work again with modern hardware to avoid digging up my old PCs each time I want to use it. The USB tower works on true hardware (On a PC with Windows XP 32-bit and the driver updated).
I can set up the IR tower in USB and in COM - since my modern PC doesn't have a COM port, I skipped this option and tried immediately with the USB tower.
I know that the USB tower doesn't work with 64-bit PCs, so I made a virtual machine of a Windows XP 32-bit on a host PC with Windows 11 64-bit. I've read that the USB tower needs a driver update to work with Windows XP so I installed it before plugging in the tower and there came the problem.
Each time I plug in the USB tower, the cursor of my virtual Windows XP freezes, the VM seems frozen but I still can press Windows and interact with the keyboard, so XP is somehow still alive (I have difficulty closing the VM too after that). After that I tried to plug the USB tower directly at the start of the VM (with a USB filter in the settings of the VM), here the VM started up, and I saw the Windows XP loading screen and a black screen appeared right after that.
I don't see if I do something bad, maybe on the host machine the tower requires something?

Hi Pikafort and welcome to Bricks.SE! I've taken the liberty to copyedit your question to get rid of some typos - please fix any places where my edits might have conflicted with your intent. Meanwhile feel free to check out the [tour] and read the [help] pages to learn more about the community and its rules and customs. Play well!

Which virtualization software are you using to run the VM? (e.g., VMware, VirtualBox, Hyper-V, etc).
Also, I posted info regarding a Windows XP VM with the Mindstorms USB tower here: https://bricks.stackexchange.com/a/18913/27192


text:
How do you take apart the 4.5V Right Switch Track with White Ties?
I have part x879cx1, and its centrepiece that moves back and forth is broken (the lever snapped off, and a bit of the track on its lefthand side). Luckily I bought a bulk lot which had a loose one of these, so I want to replace it. I don't see how to safely take it out though: I assume you're meant to move it downwards since the base of the main piece has a lip that goes over the base of the centrepiece, and, looking at the loose centre piece I have, it has a little nib at the top (which sits under the main piece), so you can't take it out parallel to the main piece. I tried pulling the centre piece out downwards, but I'm scared of breaking the main piece so I didn't pull very hard (I don't know where to put my fingers when trying, since I don't want to put pressure on the tracks of the main piece).

Also, the white part doesn't seem to be separable from the blue tracks, so I don't think I can get the centre piece out that way:

Edit:
This is a photo of the stationary part found online, showing the connection points:

I don't have such a piece, but I'd try removing the white piece first, then applying pressure from above on the round "top" part of the middle element, where the nib is holding on to the main piece. After that is clear, try pulling the middle piece "down" as per your photo to clear the lower lip.

@zovits Unfortunately the white part seems to be moulded with the blue part: I can see a bit of blue colour on the edge of the white part so they don't look like separate bricks.

That's definitely curious, can you please take a close-up photo of the interface between the blue and white parts? As far as I knew, LEGO didn't manufacture overmolded pieces before 2009

I have a feeling that it's glued rather than moulded together.

@zovits Added two images to the question for you :) The blue part leaking into the white part appears 6 times on one side, and not at all on the other. I didn't notice it before, but the studs of the white part do appear under the tracks when they don't need to.

Thanks for the photos. It seems you're right in that these parts can't be separated easily, because they have been glued together using acetone, which melts the ABS. That process produces such drop-like marks at the interface. Since the broken piece needs to be able to move, it must not be glued there - might the white piece flex enough to allow for the removal of the nib of the middle element?


text:
Bugatti Chiron built and everything worked - now pistons don’t move. What could cause this?
Built the Bugatti Chiron and initially everything worked. With the shifter in "drive" the wheels turned and the pistons moved, in neutral the wheels moved but the pistons didn’t. The reverse gear also moved the pistons. The paddles worked and changed the gearing. But now the wheels still move together, but the pistons don't move.

Hi Kelvin and welcome to Bricks.SE! Thank you for the detailed description of the issue, I hope you'll receive assistance here. Meanwhile, please check out the [help] pages and take the [tour] to learn more about this community and how things work here.

The obvious thing to clarify would be what happened between the "used to work" and "now it doesn't work" states. Was the model dropped, modified, completed, just sitting on a shelf, etc? Or to diagnose the issue yourself, you might try to follow the motion of the wheels along the drivetrain to see if the problem can be constrained to the wheels, transmission, engine or the connections between them.

The model hasnot been dropped or modified. When working the paddles changed the gears and the pistons faster or slower, depending on the gear shift. I have tried to follow the wheels alon the drive train and as a far as i can see they are connected up correctly.  I can see the the gear leaver moving the gray selector but I am not sure that the  blue and red gears are moving correct.  I can see the white gear moving correctly, whether it is in D, N or R.   It seems that the connection to engine drive shaft is not working?

Based on the comments (the rotation of the wheels is confirmedly transferred via the DNR selector and the transmission), it seems likely (and is basically the only possibility left) that the connection between the transmission and the engine is at fault. To check this, take a look at the black axle connector signified by the uppermost white arrow at this step:

If it came loose, there might not be a mechanical link that would transfer motion to the pistons.


text:
Identifying two unopened bags with earth-toned pieces
I have two bags that I need some help identifying what set they are from. I bought a mixed lot without books and seem to be a few different sets so far. Would love some assistance with these two please.

The first bag can only be from 76208 The Goat Boat:

Since the piece 18910 Panel 3 x 4 x 3 Curved with Double Clip Hinge has only ever appeared in Dark Tan color in this single set.

The Dark Tan Door, Frame 1 x 4 x 6 with 2 Holes on Top and Bottom only reinforces this.

But the second bag is from a different set, found by searching for the parts

Wedge, Plate 2 x 2 Cut Corner (at least 2)
Plate, Modified 2 x 2 with Bar Frame Octagonal, Reinforced, Completely Round Studs
Hinge Cylinder 1 x 2 Locking with 1 Finger and Axle Hole on Ends with Slots (at least 5)

This search gives two results, but the presence of the minifigure Tobias Beckett, specifically the back of his jacket  confirms it as 75215 Cloud-Rider Swoop Bikes

Absolutely is! Thank you! Appreciate your help

@Legofan You're certainly welcome! Feel free to take the [tour] and read the [help] to learn What should I do when someone answers my question? :)


text:
Need total content in Aragog's Lair, set 75950
Looking for info about Aragogs Lair, set #75950. I'm looking for the list of total parts for this set. I have 3 unopened bags with no numbers on them but they go to this playset - that's all I been able to find out. I was hoping to find out of all the total bags in the set and all contents in the box.

https://www.bricklink.com/catalogItemInv.asp?S=75950-1

Hi Robert and welcome to Bricks.SE! I've taken the liberty to edit your question to be more readable - feel free to correct anything contrary to your intention. You're also welcome to browse the [help] or take the [tour] to learn more about this site, the community that's running it and the rules or customs of contributing here. Play well!

@IvanSanchez That comment should be an answer, since this is exactly what Robert is looking for.

Both Bricklink and Rebrickable have lists of parts included within this set. I am not sure how you have identified which set your elements belong to, but based on this YouTube video (at 00:51) three bags are all this set has inside.


text:
Identifying random Lego bag
I have a random Lego bag. It has the numbers 127S5 and 1.

As usual with this kind of question: The numbers on the bag doesn't say anything about the set. I even suspect that the "1" just means it bag number 1, so we can conclude that it's a set with a minimum of 1 bag.  If you upload a picture of the bag, we have a chance, but you can also just read one of the many questions here about identifying sets, e.g. https://bricks.stackexchange.com/questions/18087/how-can-i-identify-a-set-based-on-one-or-more-original-sealed-bags

Hi Sarah and welcome to Bricks.SE! As other commenters have already noted, the information you have provided is not enough to identify the set it came from. Please edit your post with at least a photo - but more details would also be useful. Play well!


text:
Compact rotatable connection that supports pull forces?
I am looking for a "compact" (see my initial ideas for the approximate dimension I am aiming for) connection that can rotate around its axis (along the direction of connection) and that can bear a certain amount of pull forces.
I want to use it for some somewhat rigid trailer connection that can pull and push multiple trailers (think "Model Team scale" in terms of size and mass) up a slope with uneven terrain.
Some initial ideas:

A regular 2x2 turntable plate, turned up sideways. As the grip is entirely provided by four studs, at least twice (in front of and behind the turntable), not to mention the small inner turntable pin, I think this will come off too easily.
With a technic pin: E.g. a 1x2 brick with a pin connected to a regular 1x2 Technic brick with a hole. Two of these connectors were used to attach the modules of 6973 Deep Freeze Defender, and they came close to the limit of what the connection could bear there, so this is probably too weak for my use case.
The large Technic turntable is too large for my designs.
The small Technic turntable might fit and appears to allow for getting attached sturdily on both sides. Still, I do not have access to this part in real life and thus do not know whether the turntable halves would support any pull forces.
Just an axle in the direction of the connection - any such solution seems to rely on the grip of whatever prevents the axle from slipping out, which might not be sufficient.

Are there any tried and tested techniques for this building problem?

I would think the technic turntable is especially designed for the purpose you have in mind, i.e. being able to rotate while push or pull forces are applied. They are relatively cheap on bricklink.

The small Technic turntable is practically impossible to pull apart once snapped together. It can definitely handle forces that would break other connections first.

I can't answer, but may I suggest a name? A "compact rotatable connection that supports pull forces" sounds to me like a swivel.

An option for a longer axle that allows the axle to rotate but prevents lateral movement would be to use a Technic, Axle 10L Threaded with Technic, Axle Nuts as stoppers. Single axle nuts should work but for added resilience doubling-up the axle nuts should prevent them slipping on the axle as they rotate.

Wow, those are quite the exotic and antique parts! Thanks for mentioning them, otherwise I'd never known they existed - even if just until 1990.

Do you know how they were used in the models?

@A.L They were all used in rotating joints to stop the sections from separating. In the backhoe (instructions, see step 18), it was to hold the backhoe securely onto the main body and to rotate it. It was similar on the power crane (instructions, steps 12-16), holding the crane onto the wheeled body; and on excavator (instructions, step 13), holding the rotating cab onto the tracks.

I have done something similar myself a few years ago.
I used part
, axle with stop at one end. And ran that through a regular Technic brick with holes on each end of the connection. Then secured the other end with a stack of multiple half bushes . Putting multiple half-bushes against each other greatly increases the over-all friction when you attempt the pull the axle out of the set of bushes.
The half-bushes have far more clutch power than the 1L sized ones and the axle comes in various lengths up to 8L (if I recall correctly) so you can go up to 12 bushes (assuming 2L needed for the bricks that provide the mounting holes for the axle ) to add more friction.
This will give you way more holding strength than any stud-based connection would supply. And will probably be close (or better) to what the turn-table could do.
I would actually recommend to put at least 1 half-bush against the stop. I found that the flange on the stop is fairly small and weak and will deform when there is enough pull on the axle. A half bush as buffer fixes that problem.
These bushes come in variants with 4 internal ridges (as shown in the picture) and with 2 ridges. The 2 ridge versions have less grip on the axle and would be useless for this application.
And it seemed to me the yellow ones had slightly better grip than the grey ones. That might just be coincidence though, caused by minute differences in tolerances in the pieces.
A 5L axle with stop and 6 half-bushes (1 against the stop and 5 on the other end) is probably already strong enough to do what you want. And, as I said, 8L is avaialble.
If you have enough space horizontally you could even use a longer regular axle (16L or even longer) and simply use more half-bushes on each side.

I would try a 3L low-friction Technic pin, whose middle section is threaded through the pin holes of two half-width liftarms (these would be joined to the trailers), and the ends capped with 1L "liftarms" (aka. Technic cylinders or spacers) and plugging some bars (e.g. a lipstick) in the end holes to prevent the spacers from sliding off.
A shorter option would be to fix a 3/4 Technic pin in a half-width liftarm on the shorter end, attaching another one (or two) on the other end and locking both sides with any suitable 3.18 mm bar - maybe with a single piece across the whole pin.

Interesting. Your solution takes lengthwise slightly less space (using a 5L axle on my variant) as mine, but the width is a minimum of 3L and mine would fit in 2L (provided the mounting to the vehicle can be done in the vertical plane). A 2L narrow bar would also work instead of a lipstick piece (lipsticks are not very common pieces in my experience.)

This could be a good way of creating the rotation joint, but the half-width liftarms does not provide any secure way of attaching to the trailers. The half-width axle holes would likely provide too little grip. Is there another piece that could be used instead?

@sondre99v The half-width liftarms could be quite long and could extend in different directions, providing ample opportunities for various connections - depending on the available space near the connection. If empty spaces can be secured at a certain radius, additional pieces can be used to hold the liftarms against the trailers. Or just having a long half-width liftarm and attaching the trailers via 1.5 length pins blocked by bar pieces could provide a connection with enough strength that does not even exceed the envelop of the trailer.


text:
How to glue the Milky Way art piece?
I am getting ready to build the Milky Way art set that's meant to be hung and displayed. I am fearful of gluing in the process, in case I make a mistake and have to go back a few steps. This happens to me occasionally while building due to ADHD, or merely because pages are stuck together in the booklet. Is there a topical spray glue or sealant I can use after it's built to ensure it will stay together?

The recommendations in the suggested duplicate are all permanent glues, which contradict the requirement OP made regarding being able to go back a few steps in case a mistake is made.

Normally the clutch power between LEGO bricks is enough to keep them together - after all, the piece was designed to hold up under normal use (i.e. being hung). If you really want to protect it against stronger forces (for example something or somebody brushing against it), you could use a transparent spray-on glue after everything has been assembled. There are also water-soluble glues that allow one to remedy any mistakes.


text:
Does this part listed on Bricklink really exist? White 4774c01 Electric, Sound Siren 9V 2 x 2 x 1 1/3 with Two Town Police / Fire Noises

This part: White 4774c01 Electric, Sound Siren 9V 2 x 2 x 1 1/3 with Two Town Police / Fire Noises appears in the Bricklink catalog. It is visually identical to this part: White 4774c02 Electric, Sound Siren 9V 2 x 2 x 1 1/3 with 2 Space Noises.
When connected to 9v the difference between the two parts is apparent in that the former produces town fire/police noises and the latter produces space noises.
The sounds can be heard online here and here.
I have never managed to find a white 4774c01 and every one I have bought from Bricklink has turned out to be a mis-listed 4774c02 and every answered enquiry to sellers listing a white 4774c01 has resulted in them confirming an incorrect listing.
A while ago Bricklink used to list set 6483 as containing a white 4774c01 but the listing was changed to a white 4774c02. It would seem to make more sense for town sets to include 4774c01 with town sounds vs 4774c02 with space sounds.
Sets 6483 and 6482 are both town sets but are listed as containing white 4774c02 parts with space sounds.
Does anyone have a 6483 or 6482 set they have had since new and can confirm which type of 4774c0x was included?
Or does anyone own a verified white 4774c01 and can confirm that the part actually exists?

The video review of the 6483 set made by madaboutlego shows that this set did indeed make the space sounds and not the town ones. See https://youtube.com/watch?v=tDTQkA_4O7I from about 1:55.

@zovits Thanks for the link. While he does have the box, the condition of the parts looked quite used in the closeups so I am skeptical as to if all of the parts are original. I would love to see an unboxing but given the age of the sets it is unlikely.

There are sealed sets for sale on BrickLink (but they are a bit expensive) so you could buy those and do an unboxing.

@Henriksupportsthecommunity I am aware, but I already own both of the sets. I was hoping someone on here could solve the riddle without spending hundreds for sets I already own.

To answer your question, I do not actually own a set containing this piece, but if you look up "Lego coastal patrol set" on YouTube, there is a video where the guy talks about that piece - so I presume that it is indeed a real piece.

Do you have a link to the video? Because if you are referring to this one from JangBricks: https://www.youtube.com/watch?v=Bw50I0t3n8U then the part he has is the one with space noises (4774c02). See links in my original question for sound samples. Also, it looks like he pieced the set together as he is missing the radar printed tile, so I think that video is inconclusive.


text:
How do the 2x2 Sound Bricks work?
How is sound created by the Sound Bricks 4774c01 and 4774c02?
What is inside of them?
What electronic components are used to create this sound?

I don't have one to tear down right now, but I assume the contents are similar to those musical greeting cards that contain a tiny microcontroller and a piezo speaker. See for example steps 1-10 of this.


text:
Can monorail motor (2684c01a/b) be powered at 12V?
Does anyone know if the monorail motor (part 2684c01a/b) can be powered by a 12V supply?
There is this well-known article titled "LEGO® 9V Technic Motors compared characteristics" which provides information for many (if not all) of the other motors from Lego - and this supports what I have found in tests with the Power Functions M, L and XL motors, being that 12V is handled fine. However, it does not include results for the monorail motor.
The monorail motor is a much rarer and more expensive part than other Lego motors, thereby one I would really hate to damage, so I wondered if anyone had any knowledge on the subject before I start potentially damaging tests.

I apologize if this is an obvious answer, or better suited to https://electronics.stackexchange.com/, but:
You can use an inexpensive 12V→9V step-down DC/DC transformer. There's plenty of different options, but I picked a couple of available transformers in order to let you have a rough idea of their size:

The connection is straightforward - terminals marked "in" or "12V" go to the 12V power supply, and terminals marked "out" or "9V" go to the 9V motor.
Let me also quote from https://electronics.stackexchange.com/questions/448650/ :

The speed of a brushed DC motor is roughly proportional to the voltage applied, given the same countertorque.
There's a reason that motor is designed for 6V only. DC brushed motors are very forgiving, even the commutator and the bearing should stand 1.5 times the design speed for a long time.
But the gears don't.
It's most likely a plastic gearbox. Running it at overspeed will destroy the innermost gear very quickly. Don't do it.

Which means: do not connect your 9V monorail motor directly to a 12V power source. It will most probably run fine, but the gears made out of 30-years-old plastic will disintegrate.
See also https://electronics.stackexchange.com/questions/104749 and https://electronics.stackexchange.com/questions/112000/ - there's no further considerations to attaching a DC motor to a step-down buck transformer.

The information in your links is very helpful.  Having repaired a few Lego motors I know they do contain a plastic gearbox.  If it is the speed as opposed to the voltage that causes any damage then I would think that a 12V supply on a 75% PWM duty cycle brings us back to the operating tolerance of the gearbox (unless the on/off nature of PWM causes any additional stress?).  The first article from which you quote mentions a 150% tolerance for the motor itself.  Here 12V/9V = 133% so we are within that.

I read somewhere that Lego motors are in fact rated 12V but I can't find the article.  If anyone knows of it, I think it would be a valuable addition to this thread.

Finally, to shed light on the reason for considering 12V, it is simply that MN21 batteries (including holder) fit within a 2-stud space, so are particulary appealing where space is at a premium.  Whether they can supply sufficient current to operate the motor is yet to be established.

I guess your follow-up question about PWM is better suited to electronics.stackexchange.


text:
Any other Technic parts with a pinhole slot like part 18940?
I haven't kept up with new parts or sets for at least a decade, but recently when browsing BrickLink I ran into part 18940:

This caught my attention as I'm working on a MOC project right now where a major sticking point has been reducing off-axis slop in sliding motion. This is a very nontrivial problem in Technic builds because liftarms are ever so slightly thinner than a stud gap. The above piece caught my eye because it employs elongated pin-hole slots (see below) to solve this problem which results in a relatively rigid sliding connection that introduces impressively little friction.

However, these pieces have several other drawbacks, with half-stud-wide walls that create awkward spacing, and generally a lot of bulkiness that's difficult to build around just to take advantage of the pin slots. So I would like to know: are there any other pieces I am unaware of that feature a pinhole-slot like this?

I would think if the element you have in mind existed prior to when the slider elements were designed, there would have been no need to design the slider elements. There haven't been any improvements on the sliders in more recent sets. Hence I think it safe to conclude that the element you have in mind does not exist.

After scanning the relevant Technic part subcategories (plain Technic, Connector, Gear, Disk, Figure Accessory, Liftarm, Panel, Plate, Steering) on Bricklink, I'd say there is at most one such part besides your example and its various stickered versions:
Technic, Liftarm, Modified Bent Thick 1 x 11.5 Double

But the length of the slot is ... probably less than what you need.

Yeah that came to mind, but it's unfortunately definitely not a useable length of slot.

I can only think of Technic Beam Frame 3 x 19 with 2 Center Cross Beams, 3 Openings Thick being similar shape, with 3 elongated openings.

Unfortunately those are just full brick-width openings, not pinhole-width which is the specific feature I'm looking for.  It looks like there probably just aren't any other occurrences of that feature.

@PGmath you can put two half bushing onto your axle/pin to keep it aligned

Bushings are just like liftarms in that their diameter is slightly less than a stud unit, so there is slop when trying to slide inbetween liftarms.


text:
How do I make apps in Lego Mindstorms EV3 Education?
In the EV3 manual, it says you can create custom apps, in the same page as the IR control and Port View. How do you make a new app? I found a button under tools which says "Download as app", however this is pretty much the same as a usual project - is there a way to make apps special, or are they just the same?

As you guessed, the only real difference between an app and a project is which menu they appear in on the EV3.
Going a bit deeper though (and taking the title question literally), the LEGO "apps" that come pre-installed on the EV3 are not written using the LabView-based software. They are written in the LSMASM programming language, which is a language created specifically for the EV3. The source code for these can be found here.
You can modify these or create your own and compile them with the lmsasm compiler to create your own more advanced apps that can make use of all available EV3 bytecodes that allow you to do things you can't do in the other block programming languages.


text:
Type of Battery connector of Spike Prime & essential Hub
What is the type of the 3-pin connector used to connect the Spike Prime Hub or Spike Essential Hub to the rechargeable battery? It consists of 3 pins and has a male and a female side.
I have issues in charging the battery of the Spike essential Hub and want to check if the problem is with the battery or with the Hub.

If you're talking about this connector:

then I don't think there's a name for it - besides "3 pin connector (male/female)".
If you want to diagnose it, just attach pins, hooks or clamps to the appropriate contacts, as jncraton did here.


text:
Trying to identify pieces from an image
I'm trying to recreate this MOC but I'm having trouble identifying some parts just from the image.
1.) Can you tell me what part the 3 rear legs on each side are?
2.) What are the brown and beige pieces that connect at the end of its claws? The brown one looks like it has a clip on the bottom and the beige piece looks like it has a bar handle but I'm not too sure.
I figured out all other pieces but I'm not 100% sure about what is used for the butt so I would be happy to get some ideas, but it's not necessary.

The thorax is built using Reddish Brown Slope, Curved 2 x 2 x 2/3 with 2 Studs and Curved Sides pieces.

Rock and Stone brother!

The back legs consist of the following pieces:

53451 Barb / Claw / Horn / Tooth - Small
98313 Arm Mechanical, Exo-Force / Bionicle, Thick Support
92692 Plate, Modified 1 x 2 with Angled Bar Handles on Side

As for the front claw connectors, I'm not 100% sure, but it could be 25893 Plate, Round 1 x 1 with Bar Handle on Short Stem. I don't know if that piece is available in that color, though.

ah nice. i found the calw pretty quick but couldnt find the arm. thanks

@Choty Please see the following article: What should I do when someone answers my question?.

i can work with that. thanks :)


text:
Please identify yellow car-like set
I bought a bag of Lego. And one piece was not taken apart fully. Seems like a yellow car. Maybe from Technic series, but not sure. Could be older, like 2009-2014.

It is Cool Cruiser (5767) from 2011.


text:
What is this Bionicle-looking set?
Can anyone identify this set?

Apparently my father has a bunch of these, and he's trying to figure out what to list on ebay. It appears to be at least Lego / Technic compatible, but I don't know much about Bionicle sets, so I don't know if it's name-brand or a knockoff.

In my experience, those big Bionicle pieces all seem to have the word Lego and a mold number on them (albeit fairly tiny). To me, that weapon in the right hand (our left) looks like 55827c01 Inika Light-up Laser Axe, but that was in two sets, and neither is all-white like you have. So it appears to be a mix.

The white shoulders seem to be 53545 https://www.bricklink.com/catalogItemIn.asp?P=53545&colorID=1&in=A so perhaps start from there?

Thank you, those links are very helpful!


text:
What is the best way to exhibit extra large sets, like Taj Mahal?
Before buying our dream set (Taj Mahal) we are wondering with my Wife how to exhibit it properly? The set is much larger than any other construction we have (23.03x19.29x7.48 inches) and will not fit any furniture we used before for exposition.
We are wondering, what would be the best way to exhibit such large sets, so that they are simultaneously visible and safe? Should one use large glass display cases or some other solutions? I would be grateful for photos of inspiration. Should we buy some generic furniture, or custom made, or could we make it ourselves?
Certainly we would like to protect it against dust. White bricks yellows when exposed to UV light for a long period of time, at least those old one, I don't have long enough experience with the newer ones. Is the Taj Mahal prone to yellowing?

This looks like one of those times when you have too much LEGO. And I find it more (space wise) efficient to keep my big sets disassembled. There's a ton of benefits apart from being able to show off.

Hi Piotr and welcome to Bricks.SE! I took the liberty to edit your question, as here all questions are expected to have an objectively true answer - and "how do you do X" can be answered in as many ways as there are answerers. Whereas asking for the best way is a bit more unambiguous, especially since you have provided the space of possible answers and your preferences.

Disclaimer: I don't own the set in question and I'm not affiliated with anyone selling products mentioned below.
Searching in Google for "lego taj mahal acrylic cover" reveals a staggering selection of acrylic dust covers clearly intended for this specific model. Judging by the supply side I can only conclude that the demand side of the market must be equally large then. Which means many people use such a cover to both display and protect their Taj Mahal, just like you wish to do.

The Taj Mahal model has a specific issue, in that the tall minarets are not very stable and are close to the four corners of the model. A cover that protects them from being knocked accidentally would be a good idea, aside from any other issues displaying large models in general.

Just my observation. I read that acrylic could be UV Filtering or UV Transmitting and none of 5 or so covers I've checked tell which version is being used.


text:
Identify part with handle, rod and loop
I have been trying to figure out this part for 2 days now,  using every descriptor I can think of. There is no visible part number, just the LEGO stamp and 2-01. Please help!

I can remember those were used in old sets I played with as a kid (back in the '90s), mostly as kind of "blasters" with a transparent piece attached to the pin or the 1-pin part.

It was used in 42 sets form 1996-2014.  About half of those seem to be in the 96-97 timeframe, fitting kopaka's memory.

That is the Space Scanner Tool 30035.

You are awesome, thank you!!!


text:
Help identifying minifigure torsos
Was unable to identify these in Bricklink and goatleg.
Can anyone identify any of these?
Note that heads, arms, legs could mismatch. They all have the Lego logo on the neck stud.

The leftmost one is Black Widow - Black Hands from 6869 Quinjet Aerial Battle:

The second has a pair of generic grey legs and the torso of Snake Oiler:

The middle one has the legs of Blackbeard from the Pirates of the Caribbean:

And the torso of Hector Barbossa:

The fourth one is Dengar from Star Wars with different hands:

The rightmost one has the torso of the Porsche 911 Turbo 3.0 Driver:

Was just about to post this, Marvel characters are pretty iconic in their look. Middle one I believe is from Walking Dead, and I think its safe to say that they are all figures based on movie/TV IPs.

Last minifigure is not related to HP, but has Porsche logo instead.

@Thanks Alex, I have realized the difference between the Porsche and Hogwarts crests too late :D

wow! Thank you so much!


text:
Accessing an EV3 brick on computer without MINDSTORMS Home
I am trying to hack my EV3, and I know I can make it execute commands I send via USB thanks to the communication developer kit.
When I connect it via USB, it is only visible by the MINSTORMS Home app and the system report (I am on Mac).
When I try to list serial ports, with for example ls /dev/tty.*, the EV3 doesn't show, which means I can't connect to it.
However, if their app does it, then there is a way around. Has anyone encountered this before, or does anyone know how their app does it?

The Bluetooth connection appears as a serial port, but USB does not. Instead USB on the EV3 appears as an HID device. So you will need a library that provides low-level (raw) access to HID devices.

I'll try that when I'll have the time, thanks for the answer !

For those who have the same problem and are looking for a library, go here


text:
How to open first version of the pneumatic cylinder? (Part no 4688c01)
I have a Lego Technic set 8040 from 1984 with the first version of the pneumatic cylinder. Unfortunately, the shaft on the cylinder broke.
Apparently the top of the cylinder (lid) is glued. Is there a way to soften the glue (maybe with warm water) and open it? Or is my best option cutting it open and than gluing it again?

I have no experience with this specific piece, but I'd guess warm water shouldn't affect the glue. If it were to do so, then the glue could easily be softened by nothing more than direct sunlight, which LEGO would clearly want to avoid.

Thanks everyone for the answers. It gave me the courage to take the piece to the cutting block... And guess what? I now have an almost functional piece. It's not extending 100% and sometimes I need to give a little push. But at least my son can play until I get a replacement on BL.
Here is what I did:

Cut the top off with a sharp blade (yes, it isn't kind).

Inside is a rubber gasket and a plastic piece underneath it. The tip of the plastic shaft, which holds the plastic piece, was broken.

Using a piece of PVC pipe, I made a small extension and glued it to the tip of the shaft. I used superglue and baking powder for that. Here is where things could have gone better. The extension was not very well aligned with the shaft. So the plastic support became a bit off-center. Had it been better aligned, I believe the fixed piston would work better.

I placed the rubber gasket and plastic support on the shaft and used hot glue to secure the piece in place. I then put a little Vaseline inside the cylinder and closed everything with hot glue. I decided to use hot glue in case I ever needed to open the cylinder again.

It's not pretty. But it works - sorts off

Nice photographs! Please note: It is perfectly acceptable on this site to accept your own answer after a few days as "the solution".  Accepting any answer (by clicking on the checkmark to the left of the answer) will mark the question as solved make it available to cross-link it with (future) duplicate questions. And you can change your mind later and make another answer the "accepted answer" if necessary.

The original glue was solvent based. This means that both sides of the joint are more or less fused/welded together. It is not a simple case of "2 pieces with glue in between".
Any solvent that dissolves the glue will also eat the plastic itself.
I think your best bet would be to use a very sharp scalpel or thin-bladed hobby knife to carefully score along the grove around the top until you have cut through.
That should give you a nice clear cut and (after gluing it back together) should be almost invisible.
I can't give you any good advice on what glue is best to use.
I've used acetone myself a couple of times, but found it dissolving the plastic too aggressively, which makes a precision glue-job next to impossible.
(It might be ok if used in very, very small amounts.)
Polystyrene glue (used for those plastic model-kits) will work on Lego, but doesn't have much strength. I doubt it would hold the cap in place when air-pressure is applied.

It might be hard or impossible to fix this so I'd rather address how to fix the issue of having non-functional element instead. You can look into acquiring a used version of the same LEGO item from Bricklink. It might be just cheaper, quicker and easier to do.


text:
I want to recreate a few things I saw but I don't know what pieces I need. Can you identify these bricks?
I want to recreate a few things I saw but I don't know what pieces I need. Can you identify these bricks so I can buy them on Bricklink?

Most of the bricks seen there are fairly common - plates, tiles, round bricks (2x2, 1x1 and cone 1x1).
Among the "uncommon" parts I can tell:

Technic thick liftarm, 2-long in blue.
Round 1x1 plate with swirl, in silver.
1x2 plate with perpendicular technic pin on top, in white.
I can't tell exactly how the 6-stud-long round parts of the scroll are done, but I suspect some clever SNOT plus something like 1x2x1 curved slope in white.
Barb/Claw/Horn/Tooth (small) in either silver or pearl grey.
Bar 4L in reddish brown.

The SNOT in the scroll is particularly tricky - the correct alignment between a curved slope and the 2x2 round bricks cannot be achieved with the usual parts used for SNOT, as far as I can tell (bricks with stud on side, etc).
For that SNOT assembly, I'll suggest using 1x1 plate with bar handle on long stem  together with 1x1 plate with horizontal clip plus a few plates, like so:

As for the stickers, they seem custom-made.

What's SNOT? I've not heard that one before.

See https://bricks.stackexchange.com/questions/61/what-is-snot-building

I got some Technic thick liftarm, 2-long in blue and Round 1x1 plate with swirl, in silver and some Bar 4L in reddish brown. I tried putting it all together and the bars are too small to hold it all together...they  fall out of the Round plates and liftarms.

Unfortunately I cannot know how it is held internally. Maybe they're held by non-lego means, such as plasticine or clay.

Bars inserted through technic pins?


text:
Impact of Mindstorms sets being discontinued?
I was given some Mindstorms sets a while ago and I'm waiting for my kids to grow up so they can use them. Does the recent announcement of their end mean it will brick (pun intended) the kit? Will the software parts still be available for download?
NOTE: I've never used Mindstorms yet, so I'm not sure what it involves.
Side question: are they being replaced by something else?

The questions about downloads being available and being replaced by something else aren't really answerable since, one, they can only be answered by LEGO and, two, the answer may change over time. This question could be improved be rewording it to only ask things that don't rely on speculation.

Your Mindstorms kits will work as well as they ever did, as long as you don't upgrade your computer to something incompatible. This happened before with the Serial IR base.
The software is so common now that it seems unlikely you'd ever not be able to find a download, likely from Lego themselves.
I've read that FIRST Lego League had effectively already moved to Spike Prime, but I can not yet spot any official statement to that effect.

https://www.eurobricks.com/forum/index.php?/forums/topic/183377-why-are-lego-rcx-sets-so-cheap/ implies that it will, even better than the USB tower.