text:
How many 2x4 Lego bricks would it take to build a real skyscraper?
As an exercise designed to communicate the scale of plastic waste in the oceans, which was estimated at 268,940 tons in 2014, I'm trying to describe how many life-size buildings one could construct with your basic 2x4 lego pieces of the same weight. A believe a 2x4 piece is 31.8mm long, 15.8mm wide, and 9.6 mm tall, not including the studs, and 2.32g.
Naturally, I don't aspire to simulate skyscrapers that anyone could actually live in, but I'm trying to come up with a defensible estimate for the number of bricks in, say, a Lego Empire State Building (1,250' tall, not including the spire).
One idea is to imagine building a solid structure that is completely enclosed. Another is to make a hollow one with double-layered floors and a solid base.
Forgive me for the open-ended question, but is anyone familiar with the mechanics of how one builds a extremely large structure with Lego pieces that, while not necessarily structuring sound for human consumption, and least holds together?

I would have thought that the bricks would collapse under their own weight, but alas, you could build up to a couple of kilometres high! http://www.dailymail.co.uk/sciencetech/article-2242973/How-Lego-bricks-stacked-the-breaks.html

Apparently you could build a tower of 2x2 bricks 3.5km tall before it starts to collapse under it's own weight (2x4 bricks would probably collapse sooner). See also What's the Largest LEGO Construction Ever for an example of a (full size, albeit around a metal frame) house made from 3.3 million bricks.

Great question. Others may have better answers for a more "realistic" design, but the math for a solid structure is actually pretty quick. Take the Empire State Building for example:
Height: 381m
Base: 129m x 57m
Volume: 381m × 129m × 57m = 2 801 493m³

And a basic 2x4 brick:
Volume: 31.8mm × 15.8mm × 9.6mm = 4.823424e-6 m³

The number of bricks needed to simply fill the volume is total volume over brick volume, so:
Number of bricks: 2 801 493 / 4.823424e-6 = 580 810 022 092 bricks
Weight: 580 810 022 092 bricks * 2.32g = 1 347 479 metric tons

Basically, you're looking at 580 billion bricks weighing in at ~1.3 million metric tons for a solid structure the size of the Empire State Building.
This puts you at about a fifth of an Empire State Building's worth of bricks dumped in the ocean in 2014.

Yeah, a quick back of the envelop estimate for building a double layer shell, along with 102 double thick floors only comes to about 4,000,000,000 bricks. However, you'd use less if you modelled windows and doors, more for interior walls and stair cases ;)


text:
How to use the ultrasonic sensor on mindstorm NXT
I've been struggling for some time on this. I'm trying to code the robot to move when the distance is above a certain integer and stop when the distance becomes lower than the certain integer. I'm coding in Eclipse Helios. My code is below:
import lejos.nxt.Button;
import lejos.nxt.Motor;
import lejos.nxt.SensorPort;
import lejos.nxt.UltrasonicSensor;

public class robot {
    public static void main(String[] args) {
        UltrasonicSensor us1 = new UltrasonicSensor(SensorPort.S4);

        System.out.print(us1.getDistance());

        if (us1.getDistance() >= 25);
            Motor.A.setSpeed(50);
            Motor.C.setSpeed(50);
            Motor.A.forward();
            Motor.C.forward();

        if (us1.getDistance() < 25);
            Motor.A.backward();
            Motor.C.backward();
            Button.waitForAnyPress();
    }
}

Welcome to Bricks.SE! How does this behave currently? What changes to your program have you tried?

It's a little unclear from your question where this is currently failing, but I do see a couple issues with your code.
1. Your if blocks are probably not doing what you expect. You should include braces to conditionally run the block following an if statement. As written, all of your code executes all of the time. This is a tricky bug to spot, as it looks correct, but isn't. You probably want to change this:
if (us1.getDistance() >= 25);
    Motor.A.setSpeed(50);
    Motor.C.setSpeed(50);
    Motor.A.forward();
    Motor.C.forward();

To this:
if (us1.getDistance() >= 25) {
    Motor.A.setSpeed(50);
    Motor.C.setSpeed(50);
    Motor.A.forward();
    Motor.C.forward();
}

2. You say that you want the motors to stop, but it looks like you are actually reversing them. You'll likely want to change this:
Motor.A.backward();
Motor.C.backward();

To this:
Motor.A.stop();
Motor.C.stop();

Your code may still need some tweaking, but hopefully those two fixes get you back on track.

I suspect the OP is more familiar with Python, hence the mistakes in the if-syntax.....

Second if needs to be replaced by a loop... Very unlikely that the distance will be immediately less then 25 cm after starting the motors, you need to continuously check...
And stopping the motors can then be done unconditionally (i.e. outside the while loop)
Something like
while (us1.getDistance() >= 25 && !Button.ESCAPE.IsDown())
{
   Thread.sleep (1000);
}
Motor.A.stop();
Motor.C.stop();

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
What is the best way to sell complete used LEGO sets?
I have some used Star Wars LEGO sets (one is discontinued and has been for a while), some Marvel/DC LEGO sets, and some miscellaneous sets. What is the best way to sell these?

Selling is easiest via either BrickLink.com, it's direct competitor BrickOwl.com, or EBay. The "lots of money" part is the biggest problem: unless you truly have rare/collectible sets, and they are complete with instructions, it is unlikely you will make a lot of money after shipping, time spent sorting/cleaning and of course the fees levied by the marketplace of your choice. But we can definitely give you a better answer if you post the set names and numbers here ..

Making lots of money takes lots of time.  Getting money soon usually means leaving some money on the table.  So since you probably don't get to have your cake and eat it too you need to decide on what is a higher priority and go from there.

Are you sure that your sets are complete? You should verify that no pieces are lost, either by building the set or by checking LEGO's parts database (can do that on Brickset.com). If pieces are missing, you may want to order these.
On BrickPicker.com you find current market values of sets, so you know what asking price to set. That site collects eBay price data regularly. Then select marketplaces; eBay is used a lot by LEGO investors and it has an international audience of buyers. When it's time to ship your items you need to take care packaging the sets properly. To some buyers the condition of the box will be of great importance.
As you can see there's a lot of work involved with LEGO selling, and if you want to make serious profits you need to get economies of scale in your business, not just selling one or two sets.

Plus, if you have no prior selling history on EBay, and you truly have an expensive/desirable set, people will be wary of ordering with you. You would have to sell some smaller, cheaper items first to build up a reputation as a reliable seller, which takes time.

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

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Lego EV3 simulator and programming
I've been searching and testing for hours. There is little information on this subject though. I have some specific requirements for a Lego EV3 simulator and programming environment.

I do not want to continue to use Lego EV3 programming blocks.
I would like to use a robust, alternative graphical programming language such as Scratch, Modkit, or MakeCode.
The simulator needs to have access to current FLL game fields.
The programming environment and code needs to be portable to a physical robot.

I am aware of Robot Virtual Worlds and Virtual Robot Toolkit. Both are of interest to me and I am familiar with both to some degree. However, the programming aspect has been a challenge.
Virtual Robot Toolkit makes the EV3 connects to the programming platform over a virtual wifi connection. That's great if I want to use Lego EV3 programming, but I don't. So, is there another programming language that has a "bridge" to connect and program an EV3 running standard EV3 firmware over wifi? Specifically that works with VRT?
Robot Virtual Worlds has support for Robot C Graphical which is a potential choice. However, Robot C Graphical is really buggy and limited (no support for functions at all). In addition, I think the Robot C environment requires downloading a different firmware to the brick which is a drawback and eliminates it's ability to be used in VRT. I also don't know if they have any current FLL fields available in RVW.
So, does anyone know of a way to bridge one of these two virtualization platforms with a good graphical programming language while having current FLL fields available?

I don't know if this will work or not, but EV3Basic compiles to the same byte codes as the official EV3 software from LEGO, so it may be possible to use it with Robot Virtual Worlds, assuming that it uses the compiled .rbf file. https://github.com/c0pperdragon/EV3Basic

@DavidLechner This looks hopeful. I'm not opposed to teaching a simple to learn BASIC to students. It's where I started at 8 yrs old. I researched it briefly and it says it connects over bluetooth and wifi to the brick - so technically it should support virtual robotics toolkit which shows up as a wifi brick. Thanks for the tip!

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


text:
My Lego Technic 42082 wheel stuck and can't move
After I finished my 1st manual book, I found out that my crane wheel can't move. May I know which part that I did incorrectly?

LEGO Technic sets are the most complex builds in LEGO's selection, and they are not forgiving. Any little mistake, and the model won't work. LEGO Technic sets are not easy to build, as you have to pay careful attention to each and every step. In addition, if you do make a mistake, the models are not nearly as easy to take apart as regular LEGO sets.
Your issue could be anywhere. It could be a mistake of where you connected a part, you could have used the wrong part in a step, or it could be that you made one or more of the connections too tight.
Unfortunately, there is no way around it; you will have to retrace your steps and disassemble the model until you find the issue. You could take apart the whole thing and start over, or you could reverse your steps carefully, until you find the problem.
To avoid such issues in the future, you should test that everything is still working after each step. In other words, if you are adding working gears in one step, and in the next step you are instructed to add more gears or some other components, test to make sure that everything is still working correctly when you add the additional parts. You should do this after every new section. It makes building a bit slower, but it assures that the finished model is working right.
Although LEGO Technic sets are challenging builds, they are also some of the most rewarding. You can learn quite a bit about mechanics, engineering, and complex machines.

Thanks for your advise. i might need to relook into all part. :)


text:
Help identifying giant blue LEGO Bionicle set
I have what appears to be a giant Bionicle. The head is the size of a small human head almost the size of a mask.
It is blue in colour and in 5 bags. It looks like more than 100 pieces. The instructions and box are lost. No idea what it is.
Any ideas? Can post pics if needed.

Picture would definitely help. There are a number of sets I can think that this might be.

It's better to post pic

Gadunka (8922) came somewhere around 2007, and was part of the underwater themed bionicle sets. When assembled it is quite big. Maybe this is set you were looking for?

Another candidate would be the 8894 Piraka Stronghold or "Lava Chamber Gate":

as it contains the largest Bionicle mask/head piece in blue.


text:
What is this 2x4 brick with a 2x3 rounded plate with hole attached?

I found this LEGO brick and have no idea what it does, it’s name, or which set it is from. It is a 2x4 brick with a 2x3 base plate with a rounded end and a hole in it.
Can anyone tell me about this brick?

Great question! Welcome to Bricks.SE!

For more on the history around the use of these, and the use of glue to attach the figures to some of them, see this answer here.

It's a magnetic base that minifigs are attached to.

Hi @Isaac, if Alexander has answered your question, you can also click the tick mark below the vote counts :)


text:
What is an effective way to clean clear LEGO bricks?
What kind of cleaning products are good and safe to remove smudges and finger prints off clear LEGO parts? Normally I would just use the Clorox wipes. The parts in question are 1x2x2 panels in clear plastic.

Almost all LEGO can be washed with dish soap and warm water (Do not use dish washer soap though, it sometimes contains grit to help grind off dried food. This will scratch your bricks)
Second best option is windex, which isn't too bad for plastics.
I would advise against clorox wipes though. I believe they contain bleach, which while is great for getting things clean, it will react with the ABS plastic.
I tried bleaching some old lego a number of years back, and I soaked the bricks for a day or two and I found that, while they wer very clean, they also slightly expanded as a result of reacting with the bleach. They are very sticky, and are hard to separate now. Additionally, they seem a little harder and less flexible.
Note that this occurred after being immersed in a water bleach mixture for extended time. One swipe of bleach will probably not have much effect, but it shows that it does react with the plastic, so that is why I suggest against it.
Warm water and dish soap cures most problems.


text:
Can you identify a set containing a zebra and spider minifig?
I have 2 bags of unopened Lego bricks but I cannot determine what set they belong to...bag 2 344R6 and bag 4 344R6. They are probably from Lego Junior. I can tell there is a zebra character minifig and a spider character minifig.

Welcome to Bricks.SE! Can you post a photo of the bags?

I don't think the marking you quote identifies the set, but with pictures we are often able to help.

@Lindsay: It sounds like we have an answer you're happy with.  Could you click the check box by the answer to "accept" it?

Batman baddie ZEEEeeeebra-Man,

and tough gurl TA-TAH-Taaaarantula !!!
From Set 70907-1 Killer Croc Tail-Gator.

You guys are the best! That is it! Thanks so much! I have a very happy 5 year old!

You're welcome Gurl!  Happy to help!


text:
What dark green and lime BIONICLE do I have?

If anybody could tell me what BIONICLE this is I’d greatly appreciate it, it’s driving me mad!

My answer totally springboards off of Alexander "Hawk-Eyes" O'Mara's astute observation of its suspected authenticity.  Nice job Alex.
I looked up BIONICLE knock-offs and got a video that named the brand as "конструктор последний воин", then Google Image searched that phrase for a pic of our Greenie Meanie, and Voila!:

Google translates the Russian/Mongolian to:

"конструктор последний воин":
"Builder of the Last Warrior".
And this guy is named "ЛИЗОРД":
"Lizord" or Lizard.
The toy maker is, "1Toy Растем вместе!":
"1Toy Growing Together!".

There seems to be an entire, Builder of the Last Warrior line, with at least one dedicated community called RUSBIONICLE.

Impressive investigative work! I gave up after a Google image search yielded no results.

Thanks heaps Rin and Alexander! This was kinda surprising, but I was starting to suspect it may have been a knockoff. It just seemed like LEGO quality. Cheers

Thank you for this! This question was keeping me up last night, and I just couldn't find a match. I started suspecting it was a clone, but I'm not familiar with clones for Bionicle sets. Great work by both you and Alexander!

It's not a BIONICLE set or a LEGO set. The pins and axles aren't right for an official LEGO set, so I think this is some random BIONICLE-look-alike set by another brand.
LEGO pins would have a round center, not a flat one:

This axle hole in his hand appear rotated 45 degrees off the LEGO piece that looks like this.

I've never seen a LEGO piece that looked like this:


text:
Can you identify the set these white vehicle elements come from?

We got this big box of Lego bricks, and we don't have the manuals, please help!

I'd hazard a guess for 3661-1 Bank & Money Transfer, based off your Minfig, which shows up in only one set.

Free build instructions here at LEGO.com if you have all the pieces to this set.


text:
Program for NXT golf robot not looping properly

This is what I made:

I will put this robot straight in line with the ball
I have to make this robot go forward and once it reaches the ball, I have to make it stop and hit the ball with the swing shown in the picture
I used ultrasonic sensor to determine if it reached the ball

It has to identify if it's a red ball or blue ball with the light sensor.
If it's a red ball the robot should hit the ball and if it's a blue ball it shouldn't hit the ball.
I used while and if statements but it doesn't seem to work properly. If I use break; then it stops the program instantly when I start it, so I didn’t use break, but if I start my code, it goes forward and stops and then continue this
It just wouldn't go continuously
Here’s the code I wrote:
#include "NXCDefs.h"
task main() {
  SetSensorLowspeed(S2);
  ClearSensor(S2);
  SetSensorType(S1,SENSOR_TYPE_LIGHT_ACTIVE);
  SetSensorMode(S1,SENSOR_MODE_PERCENT);
  ClearSensor(S1);

  while(true) {
    OnFwd(OUT_AB,75);
    if(SensorUS(S2)<=16) {
      OnFwd(OUT_AB,0);
      if(Sensor(S1)>49) {
        OnFwd(OUT_C,-70);
        Wait(2000);
      }
      else {
        Wait(500);
      }
    }
  }
}

Looking at your code, there are a few things that you need to consider.
Firstly, you have a while (true) loop which will run infinitely.
The first thing you have after the loop is OnFwd(...) which will turn motors A and B on.
Together, this means that whatever you do next, when then you will run the code again, turning on motors A and B.
The next thing to be aware of is that Wait(2000) is milliseconds. 2000 milliseconds is 2 seconds, so you will only turn motors A and B off - stopping the robot - for either half a second, or 2 seconds before the loop starts again, and the robot starts moving again.
In the case where both if statements are true (presumably when it detects a red ball - but I haven't double checked either the Sensor or SensorUS commands), the robot will stop, the motor C will start, then 2 seconds later the robot will start again.
I would suggest increasing the values in the Wait statements (you could use time constants such as SEC_5), and adding a break; after the Wait(2000);


text:
How much do the PF XL motors help speed in the 4x4 crawler?
I'm wanting an answer if anyone has swapped the PF L motors in the 4x4 crawler to PF XL motors and if this increases the speed or not.

You can speed up the Bucket Wheel Excavator by adding an additional XL motor. It is not just about changing the motor, it is also about changing the gear ratios. There is a very good instructional video here: https://youtu.be/aLQh_VWzy9Y


text:
How do I connect part 62113 together to form a ladder?
I am looking to build a ladder. I saw part 62113 and was wondering if its possible to connect part 62113? Here's what that part looks like:

Welcome to Bricks.SE!

There are many ways to connect these together to form something like a ladder. One simple way is to use this fairly common arm element (30377):

This technique is shown on the ladder in the Creator Treehouse (31010):

Here are the relevant instruction steps in case it is hard to see in that photo:


text:
Is there an API for the Duplo 10874 train set?
I intend to buy this train set for my daughter. Apparently, the locomotive can communicate with an app via a bluetooth connection.
My question is: is there any documentation available so that I can make my own app to communicate with these trains? Preferably, I'd want to connect with multiple trains at the same time. Then it'll be fun for her to play with the set and fun for me to program for them :-)

There is now official documentation for the Bluetooth protocol used by the Powered Up product line:
https://github.com/LEGO/lego-ble-wireless-protocol-docs
The community has created some tools to interact directly with Powered Up and Boost hubs. Here is one example:
https://github.com/nathankellenicki/node-poweredup
That tool supports basically every device using the Powered Up Bluetooth protocol, including the new Duplo trains.

Official docs:

https://lego.github.io/lego-ble-wireless-protocol-docs/
https://github.com/LEGO/lego-ble-wireless-protocol-docs

Discussion:

https://www.eurobricks.com/forum/index.php?/forums/topic/162288-powered-up-a-tear-down/&page=3

Inofficial modules:

NodeJS: https://github.com/nathankellenicki/node-poweredup
Python: https://pypi.org/project/bricknil/

Products (based on "Push & Go" train base "Model: HUB NO.5 / IC: 3027A-28743"):

https://www.lego.com/product/steam-train-10874
https://www.lego.com/product/cargo-train-10875

Related:

How to disassemble LEGO train engine base part# 28743?

Thanks for sharing, and welcome to Bricks.SE! That's a lot of useful information!


text:
What is the best way to sell sealed LEGO sets?
My kids have inherited a massive LEGO collection. 90%+ is in mint condition, still sealed. There are thousands of sealed boxes - currently kept in storage. There are plenty of open sets that the boys will keep, but the bulk we are looking to sell. What is the best way to do this? Any advice would be appreciated. A large amount of sets are Star Wars.

Possible duplicate of What is the best way to sell complete LEGO sets?

I vote to keep this one open, since TJM is asking mainly about new and sealed sets in perfect condition. This excludes all efforts to check for completeness etc.

I've edited both this question and the linked possible duplicate to make it clear that this question is for NIB sets and the other is for open sets.

That sounds good to me.  It seemed like a dupe at first glance, but it was challenging finding the other "one".

If you really have that much (hundreds or more sets to move), you have some options:
Set up a Ebay store:
    Up front cost: None
    Profit: ~80% of net (Ebay takes a cut, Taxes, shipping materials)
    The slow burn option. You will eventually get rid of everything, but it will take some time, and many trips to the post office.
Go rent a table at a local Lego convention:
    Up front cost: probably a few hundred bucks
    Profit: After the booth /table cost, all the money is pretty much yours.
    This will get rid of stuff fast if you go to a sizable convention and you price reasonably. People buy a lot of lego at Lego conventions. You will have to plan this in advance, since tables might require being reserved months in advance.
Find a reliable Lego collector to sell it for you:
    I had a good friend who is an active member of the local Lego community do this for a family who acquired a huge vintage Lego collection. I think he took about a 20% cut and had most of it sold off in a few months. The upside of this approach is that you don't have to do anything but count the money you make. Make sure you get someone who knows what they are doing though. Older collectors are good choices, since they know a lot of the history of sets and themes.
I don't know how good sites liek Bricklink are for selling sets. It is a fantastic place to buy sell loose parts, but I don't know how quickly sets move there.


text:
Help me identify what set this bag of mostly white tiles and panels belongs to

Can anyone tell me what set this bag belongs to?  It could be 2011 but not sure.

Have you tried to check the set inventory of the 10214 Tower Bridge? It seems that you have several bags from that set.

As Aziraphale hinted at in a comment, this is a bag from Tower Bridge (10214).

You can see this bag clearly in unboxing videos.


text:
How do I connect the LEGO Powered Up remote control?
I'm trying to use the Powered Up remote control to control my new train set, but it doesn't seem to work. Is there some process that I need to follow to connect or pair the remote with the Smarthub?

The Powered Up system uses Bluetooth for control, so the remote needs to be paired with the Smarthub. To accomplish the pairing between the Powered Up remote and the Smarthub, you simply press the green buttons on both devices at the same time as shown in the instructions and in this review by Beyond the Brick:

If the pairing process works correctly, both devices should have their lights lit up in the same color.


text:
Is there a current source for the LGEO parts library?
I'm working on a povray render of a model. I've seen the LGEO (not a typo) part library referenced in various places, but I haven't been able to find a working download link.
Is there a current source for an updated version of this part library?

Perhaps this Eurobricks thread is helpful: https://www.eurobricks.com/forum/index.php?/forums/topic/108739-new-parts-for-lgeo-library/
It seems that the lgeo library itself is no longer maintained but this person maintains his own version. The download links are on the first page...

The library you linked to does not include the original LGEO parts by Lutz Uhlmann, nor the updated parts by Owen Burgoyne.

As stated in your "various places" link, the LDraw.org web site maintains an All-In-One-Installer (AIOI) which contains and installs LGEO and is updated in January every year so I assume they use the latest version of LGEO.
BTW, I found an LGEO quirk when launching POV-Ray from within LPub3D which I use for generating building instructions.  I kept the screenshot below highlighting how you have to tell LPub3D that LGEO is not available, even though the AIOI installed it:

Thanks for that. I was aware of the AIOI, but I don't use Windows, so it's not super helpful. In addition, the LGEO link on the AIOI page 404s, so it wasn't clear if this is updated or not.

Sadly the AIOI download doesn't allow easy extraction of it's contents. You'd need to install it on a Windows instance and then grab the LGEO stuff. However I think Michael's link to the forum is your best bet for up to date parts.

This wiki page describes how to get all the LGEO parts.
https://wiki.ldraw.org/wiki/LGEO

This is now available on Github.
I was able to find a working download of just the original LGEO library on Eurobricks thanks to some help from the other answerers. I trimmed that down a bit, as that download required integrating some other files in order to work properly. This repo should now work perfectly on its own, but it only includes parts up through 2008 that were created by Lars Uhlmann.
If you are looking for a more complete and cutting edge set of elements, Darats' version (from the accepted answer) seems to be the most current and high quality.


text:
Looking for ideas to make wire connectors compatible with Lego Functions
I like to make custom battery packs for Lego Power Functions. Is there any simple way to make wire connectors?
The only option that comes to my mind is to buy LEGO Power Functions Extension Wire # 8886, cut the wire, and connect it to my custom battery pack. Would that work? Is there a better idea?

The only option comes to my mind is to buy LEGO Power Functions Extension Wire # 8886, cut the wire, and connect it to my custom battery pack. Would that work?

Yes it would work, and people have done it.
Here's a YouTube video someone has made on their own custom Power Functions batteries.

Is there a better idea?

I don't think it would really be possible to produce a Power Functions compatible connector for less that the $3 LEGO charges for their cable at a small scale, so that's probably your cheapest option.

The video is helpful. When I searched youtube, I could not find anything. May I ask how did you find the video?

@AllanXu I had searched custom lego power function battery on YouTube, and it was one of the results.

Yes, I have done so. Wanted to motorize the Wall-E set. Initially did so with a AAA lego battery box in his belly, but with the wires and everything, not really enough room.
So I indeed cut up an 8886 extension wire and connected the wires to a clip you can get in any electronics store on which fits a 9V block battery.
When powering an SBrick or IR-receiver, only the outer wires need to be connected to the clip. When connecting immediately to motor or PF switch, only the inner wires need to be connected.

I made a battery holder following these instructions:
www.instructables.com/id/Lego-AA-Battery-Holder

It works great even without glue. It requires only Lego and 4 clips.

Welcome to Bricks! That looks like a nice way to make a custom battery box. Unfortunately, this doesn't appear to answer the question about how to make connectors for a custom battery box. We're really looking for answers that directly answer questions rather than those that might add to a conversation.

Thank you for your suggestion. This triggers so many other good ideas as well. The idea can be done with simpler bricks as well. Perforated bricks are harder to find.

This is just an alternative way =) Do not use (and try to somehow connect) the original holder, but make everything from simple parts...


text:
Is there a list of the most common Lego Technic parts?
I searched the internet for this and I found a list of complete sets. But I am looking for a list of the most common (and in some sense the most important or most helpful) individual Lego Technic parts. Is this available somewhere?

I'm guessing that this would probably be the Technic Pegs (with or without the friction nubs), as most Technic sets include a fair number of them to join things together, followed by axles and cogs.

On Brickset, you can browse parts in the technic subcategory and you can  sort by "Set count", i.e. the number of sets the element appears in.
https://brickset.com/parts/category-Technic
So that would take care of your "most common" requirement. I'm afraid that "most important" or "helpful" is rather subjective and hence difficult to quantify and have lists sorted by those measures...

Big +1 for solution that works for "most common" anything and likely will not get outdated.

And then you also need to click through to sort by "number in each set" - for example the "Connector Peg with Friction" not only comes in the most sets (almost 1900 at the time of writing), but it's also in very large quantities, the first 30 or so results contain at least 200 of them.

724 in the bucket wheel excavator, you can use bricklink for an accurate part count, it doesn't source its inventories from the lego replacement pages, they're done manually.
We should take into account the nature of this element though; it's THE pin, it's how you connect things with technic, basically having the same function as studs in system lego...


text:
Is it legal to sell a custom element that provides a Technic pin connection?
I'm wondering if it would be legal to produce a custom piece for Lego Technic and sell it? The piece features 4 compatible connection holes for Technic pins. From what I've researched in the Lego Technic patents, the claim (in the first sentence of each patent) applies to "sets" not individual parts. Here are the patents:

https://www.google.com.gi/patents/US5964635
http://www.google.com/patents/US6736691

Does anyone know if there are specific patents covering the pin hole system?
Note: I would of course make sure to use my own designs and not copyright infringe on any of their trademarks regarding packaging, marketing etc.

I am not a lawyer, and I recommend you consult one before you start dropping money on injection molds, but as far as I know this should be fine. SBrick definitely already does this:

In most jurisdictions, patents have a term of 20 years or less. The Technic pin connection dates back to Expert Builder in 1977, so it is not patent encumbered at this point.
The two patents that you linked to from the late 1990s appear to be for ZNAP, which uses a different connection system:

Many companies with LEGO-like products seem to get away with simply stating "compatible" on the box. They don't mention LEGO but everyone knows what this toy is compatible with.

Thanks jncraton. That makes things cleaer. I will consulate a lawyer before investing any money into it. If by chance you know where to find the patent from 1977 it would be much appreciated! I can't seem to find it.


text:
What are these strange black disc LEGO pieces?
What are these discs? Ammo maybe or ice hockey pucks? I did not find any id numbers.

That would be Sports Hockey Puck, Large:

It comes from the larger Technic-based Sports Hockey sets from 2003-2004.

(Puck in the above set has stickers.)


text:
How do I see which stores have all the parts I want on Bricklink?
If there are four different parts I am wanting on Bricklink, is there an easy way to see if one shop has all four? I would want to get it from one shop to reduce shipping. I know I could do it the long way, but if I don't find one early it could take a while.

Not sure if this answers your question, but what I did was I added the bricks I wanted to my wanted list. Then I clicked Easy Buy. Another way is to click on your wanted list, click buy all in the upper right hand corner, and this you will see a scroll down tab/list that is labelled sort by. Just select min buy and click auto select. However, I'm not sure about the shipping problem.

I just want to find them all in the same shop.

Sorry, not sure about that...

The way to do it is to make a wanted list in BrickLink, selecting all the different pieces and quantity of each that you want.
Then select all of the items by checking the boxes next the items you want or selecting the upper box to select them all and then click the green buy items button, this then brings up a list of stores selling the items.  The list is sorted by which store has the most of your selected items available to sell.  The two important columns on this list under each store is "unique lots" which is how many of your different parts the store has followed by "item count" which is the quantity of those items they have.
If you then click on the individual store, their shop will have a wanted list tab, which will show you everything on your wanted list that they have to sell.
It's not uncommon to have to purchase from multiple shops to get everything (different items and quantity) you need/want.  So it often requires checking multiple stores to combine it into the smallest number of purchases, I am not aware of any automated method of doing this, I just end up opening multiple tabs in my browser from the list of stores generated by my wanted list query and figure out the best option myself from there.


text:
How do I install the Lego BOOST software on a phone instead of a tablet?
Officially, the Lego Boost software is only available for devices with at least an 8 inch screen:
https://www.lego.com/en-us/service/device-guide/boost
However, it would be nice to install the software on an old phone rather than a tablet for my child to use. Is this possible? How?
Edit: LEGO now officially supports tablets and smartphones. This question is now mostly irrelevant, but it could still be useful as a guide to installing the app on an unsupported device.

You can install the software using an alternative App Store such as APKPure. You can alternatively download and install the APK and OBB files directly from various online sources as demonstrated in this video. Once installed, this software seems to work for me on my Galaxy S4, and I assume it would also work on other Android devices. I can connect to and control the Move Hub without any issues, but I haven't tested all features of the software.
I was unable to get this to work on an S3. The app crashes during the loading screen. This could be due to many factors, but I suspect screen resolution could be one culprit, as the S3 has a 720p screen and the S4 has a 1080p screen.
It should also be noted that these devices aren't officially supported by TLG, so this software may be buggy and/or stop working in the future.
Devices confirmed working:

ASUS ZenPad S
Google Pixel C
HTC Nexus 9
Lenovo Yoga Tablet 2
Lenovo Yoga Tab 3
Nvidia SHIELD Tablet (LTE)
Samsung Galaxy Tab S
Samsung Galaxy Tab A
Samsung Galaxy Tab S2 (Nook)
Sony Xperia Z2 Tablet (LTE)
Sony Xperia Z3 Tablet Compact (LTE)
Xiaomi Mi Pad 2
Samsung Galaxy S4
LG G3
Samsung Galaxy S5
Google Pixel 2
BQ Aquaris X5 Plus
Huawei P10 Lite
Motorola G5 Plus

Devices confirmed not working:

Galaxy S3

The official list of devices can be found here
https://www.lego.com/en-us/service/device-guide/boost


text:
Why is there a hole in the large surf board (6075)?
Why does the large surf board (part 6075) have a large hole in it? The hole is larger than a normal stud. An example of this part is found in red in Coast Guard Starter set (60163):

Here's a closeup of the board so that you can specifically see the large hole that I'm asking about:

This part is sometimes used to build a windsurfer as shown in Stephanie's Beach House:

The hole is larger than a stud because it is designed to receive a towball connection of some kind, usually a mast such as this one:


text:
Saturn V set from the 60s?
I have some of my dad's old Lego sets from the 1960s when he was a kid. There are circular discs that fit on top of each other to connect and form a rocket. Is this a Saturn V rocket model (the ones that took the Apollo astronauts to the moon) or perhaps some other rocket? What Lego sets like this were available in that period?

Welcome to LEGO Answers! If you have these pieces handy and could upload a photo, we could identify the set they come from more easily.

Yes, well, they are currently  in a bin with about a 1000 of my kids' other Legos.

It's hard to answer this definitively without a picture identifying the exact parts you have, but this sounds a lot like the set Rocket Base (358-1) from 1973:

That was one of the first space themed sets. The round parts are similar to what you've described. It looks like an obvious tribute to the Apollo program, though it isn't licensed or branded that way.

The rocket pieces look exactly like what I have, but I don't recall ever seeing those antenna pieces. Maybe they got broken before I came around though.

I could certainly imagine those antenna pieces breaking or going missing. Do you have the red baseplate that this is built on? Red baseplates are uncommon, and the one for this set also has a unique dot pattern: http://peeron.com/inv/parts/10p03

I'm not sure about the baseplate. I vaguely remember a broken piece we got rid of when I was a kid that might have been that. Or not. I'm going to have my dad take a look at this.

Those antennas are notorious for breaking, so I could easily imagine them being tossed sometime in the last 45 years, which might explain why you don't remember them.


text:
Is using the term "Legos" always wrong?
LEGO tries very hard to protect its brand name. There is a company policy to use the expression "Lego bricks" rather than "Legos."
I am fortunate to live close to a Legoland and a LEGO retail store. However, I occasionally hear an employee say "Legos," and of course the (American) public uses "Legos" all the time.
Is this incorrect? Are we just being lazy?

No. It's not wrong. It's just sad that no one corrected them when they were young. I blame their parents, really.

See also the answers to Can anyone find a photo of the "LEGO Bricks" not "LEGOs" insert and the Meta question "Do we use LEGO or LEGOs" for both TLG's policy on usage and ours ;)

You can say "Legos" if you want to. But for The LEGO Group it's an important matter, because if people start saying "Legos" about similar products produced by other companies, LEGO might lose their brand if it is deemed genericized.
For instance, see Wikipedia which has an entry about "Legos" in the Generic trademark article:

The Lego Company has worked to prevent the genericization of its plastic building blocks following the expiration of Lego's last major patents in 1978. Lego manuals and catalogs throughout the 1980s included a message imploring customers to preserve the brand name by "referring to [their] bricks as 'LEGO Bricks or Toys', and not just 'LEGOS'." In the early 2000s, the company acquired the Legos.com URL in order to redirect customers to the Lego.com website and deliver a similar message. Despite these efforts, many children and adults in the United States continue to use "Legos" as the plural form of "Lego".

For LEGO guidelides, see this picture:

(I feel like this should be pinned to the homepage or something, as I've seen this question a LOT.)
Here is a link to their official policy statement:
https://www.lego.com/en-us/legal/legal-notice/fair-play
Relevant excerpts:
"A Trademark must be Protected
A trademark must be able to distinguish the goods of one company from those of another. If a trademark loses this ability, the owner may find that it can no longer prevent others from using the trademark. An owner must prevent the improper use of its trademarks to prevent the public from being deceived. This is why the LEGO Group is very active around the world in making sure that its trademarks are not misused."
"Proper Use of the LEGO Trademark on a Web Site
If the LEGO trademark is used at all, it should always be used as an adjective, not as a noun. For example, say "MODELS BUILT OF LEGO BRICKS". Never say "MODELS BUILT OF LEGOs". Also, the trademark should appear in the same typeface as the surrounding text and should not be isolated or set apart from the surrounding text. In other words, the trademarks should not be emphasized or highlighted. Finally, the LEGO trademark should always appear with a ® symbol each time it is used."

authors: Никита Белоокий


text:
EV3 not recognized by PC when attempting firmware update after interrupted update
I have just sent the following inquiry to Lego Customer Support:

I aborted a firmware update and now the Intelligent Brick does not get past the "Starting.." message when it is turned on. I followed the instructions at http://www.legoengineering.com/ev3-gone-wrong-what-to-do-when-your-ev3-stops-working/ and I can get the Brick to switch to updating, but the EV3 software on my PC does not see that the Brick is connected via USB cable. Is there anything else I can do? The Brick is new and should be covered by warranty - how would I send it in to exchange it?

I'd appreciate answers to either question.

I've edited and reopened this question after reading your comments on other questions. It sounds like your problem may be one we don't already have an answer for. For others, here are two related questions: http://bricks.stackexchange.com/questions/7642/ev3-screen-stuck-at-starting and http://bricks.stackexchange.com/questions/2688/ev3-brick-cannot-connect-my-to-computer/2696

You have done the right thing by contacting Customer Service. They'll be able to help you potentially fix this or replace the part if needed.
I know you said that you already tried this, but I wanted to list the steps for a firmware update here in case others find this question. Here's the exact language from the EV3 user guide:

Forced Firmware Update
If  you  need  to  update  your  firmware  manually,  follow  the
  steps   below.  (Note: the EV3 Brick still requires a USB connection
  to your  computer)

Make sure your EV3 Brick is turned off.
Hold down the Back, Center, and Right buttons on the EV3 Brick.
When the screen says “Updating”, release the buttons.

If the manual firmware update does not make your EV3 Brick work  the
  first time, repeat the manual update process.

Here are some general things to try if you haven't already:

Take out the EV3 battery and unplug from your computer and just let the brick sit for 30 seconds or so. Repeat the above steps.
Reboot your computer, or try using another computer, and repeat the above steps.
Try using another USB cable and/or USB port and repeat the above steps. This is unlikely to help in your case since the cable just worked for you, but it could be helpful to someone else.

Please post back here if Customer Service is able to provide a fix for this issue, as I'm sure it will help out someone else.

authors: ساره المقبالي


text:
Unknown stickers with silver lines on black 2x4 tiles
I found two stickers in a bundle that I can't link to any set.

Do you know which sets they may belong to?

Comes from Set #76047 Black Panther Pursuit.


text:
Can you identify this white, blue, and green train body?
Got that is a bag of parts. For some reason one part of train (it look like train to me) is upside-down by direction of stubs. Browsed through all 4 hundred sets by searching for 'train' on Bricklink but had not spotted that one.

I do not know much about LEGO, but that what you show in the photo looks like an airplane to me. Perhaps I'm right, perhaps I'm wrong.
Edit:
It's from A.I.R. Operations HQ (4620).

Yep, look like you are right. Similar although with different coloring https://www.bricklink.com/v2/catalog/catalogitem.page?S=4619-1&name=A.I.R. Patrol Jet

found the one with right colors - it's from https://www.bricklink.com/v2/catalog/catalogitem.page?S=4620-1#T=P

Thanks for your contributions, and welcome to Bricks.SE! I've edited this answer to be more complete based on the info from @AlexeiMartianov comments.


text:
Can several users control one Powered Up train using different devices?
According to this review of the new 60197 passenger train you can only have one Bluetooth thing talk to the new LEGO battery box at a time.

The new Power Up system as it currently appears in this set is very rigid. One remote or device can be used to operate one battery box/receiver, which in turn can operate one train motor. All of the flexibility of the old system seems to be gone.

I'm hoping to put a train in my office before Christmas and it would be great if multiple people could install the app and change the speed.  Is that too much to hope for with LEGO's current evolution of this technology?  This seems like a normal thing to expect for something that uses Bluetooth, but the review above makes me doubt that applies to LEGO. Has anyone tried this?

As far as I know, this is not possible using the current stock firmware. The battery box can only pair with one device. The UI on the battery box is a single button, and for simplicity the device is either in a mode where it is looking for a device to pair with (flashing light) or already paired (solid light). There isn't a way to pair it with another device once it is already paired, and pressing the button while paired cancels the current pairing.

I'm hoping to put a train in my office before Christmas and it would
be great if multiple people could install the app and change the
speed.

There are ways to allow multiple people to control a device, but it will likely require a bit of software development.
Update
My students and I have been working on a possible solution to this problem that I wanted to share. We've created an open source project for the Raspberry Pi called twitch-powered-up that allows a LEGO model to be streamed from a webcam and controlled via simple natural language commands on Twitch chat. Here's the basic idea:

I can confirm that using something like jncranton suggested (a third-party library that speaks to PoweredUp devices over bluetooth), you can use a computer to control several PoweredUp devices at once.
The limit seems to be the number of devices your Bluetooth will pair with.
The Remote is a smart hub like the battery box so each remote counts as one device and each battery box likewise counts as one.
When paired in this fashion, the buttons on the remote do nothing. You'll need to write code to dispatch messages to the battery box to perform whatever action you want your remote to control. I wrote a script that makes the remote behave like the remote in the box, i.e. it makes the train go faster or slower. But as the train only uses one side of the remote, I programmed the other buttons to raise and lower the gate at the level crossing, using a Boost brick which was also part of this program.

I've done some experimentation with using one powered up controller over two hub devices ... ( You must have one motor on channel A in Hub 1 & the other on Channel B in Hub 2 ) Seems to work, pairing involves turning on all devices at once, ( controller & Hub ) and waiting for it to sync + same with turning it off - press & hold all devices for 5 sec ...
The other program I've looked into ( but not tried yet ) is "The Lego Train Project". Found here : https://www.eurobricks.com/forum/index.php?/forums/topic/169318-control-all-your-powered-up-power-function-sbrick-devices-with-a-single-software/
Add : This program requires windows 10 to operate ... :(
Should give that a go to see if it can control trains from multiple locations ... :)

I'm glad folks are writing software to solve this problem, but I don't use Windows anymore so I can't try this one out.

Yeah, same here - I don't have a window's 10 system ( yet ) ... :/


text:
Why does the Duplo bathtub piece have an odd height?
I have recently come in touch with the Duplo bathtub piece.
While it is mainly a bathtub whose bottom is shaped in such a way that it can be placed on Duplo studs, one of the piece's sides also features two studs on top. This suggests the bathtub can be integrated into other constructions such as walls, similarly to other furniture pieces such as the toilet piece.
Curiously, though, the bathtub does not seem to have a height that fits with other Duplo bricks. It is taller than a Duplo brick, but not as tall as 1.5 Duplo bricks (or a Duplo brick plus a Duplo plate).
Why is that? Is there any way this non-standard height can be advantageous, just like e.g. the Erling brick's reduced depth that allows for sideways and upright integration? Can I combine the bathtub with its odd height with anything else at all?

One of our first ideas was to have the slide end in a bathtub. But with the bathtub's non-standard height, building a support for the slide is tricky.

I don't know why they didn't make it a standard height, but the studs on top are for attaching a shower head.

Although we probably won't get a definite answer to why this decision was made, unless a LEGO part designer steps in to answer the question, here are some things to consider.
The LEGO DUPLO bathtub, toilet, and sink all have two studs at the end. Looking through all the sets these pieces appear in, the studs are used for attaching accessories, like a shower head (for the bathtub), mirror (for the sink), or printed bricks with various bathroom accessories. They are not made to be integrated into a wall (at least not as a primary feature).
Even though the toilet and sink are 1.5 LEGO DUPLO bricks tall with two studs, I can find very few examples when this was taken advantage of by incorporating the pieces into a wall. In the vast majority of LEGO DUPLO sets, the bathtub, toilet, and sink are freestanding next to a wall, and often next to each other. To mimic realism, the bathtub needed to be shorter than the sink, but tall enough to fit a figure - thus the odd height.
In the case of LEGO DUPLO accessories, furniture pieces, and fixtures, this is often the case. LEGO DUPLO element designers will make sure a piece can fit with other pieces in at least one primary way, but there are other considerations as well, like scale in relation to other pieces and fitting the figures properly.
We should remember that while LEGO DUPLO is a construction toy, it is meant to be for the youngest of children. So, while building and rebuilding is possible, the parts are not designed to be attached using complex building techniques or repurposed in many different ways, as we see in LEGO System sets.
As far as the idea of integrating the bathtub with the slide, how about putting a couple of LEGO System plates under the pieces to even out the height? LEGO System plates are compatible with LEGO DUPLO if placed on the underside. I do not have the pieces to test this out myself, but OP's question made me curious.


text:
Can a v1 PF reciever power an XL motor and servo?
I have a v1 PF receiver but don't want to pay $35 for a v2 receiver and I was wondering if a v1 receiver can power a single XL/L motor and a servo.

I just tried connecting an XL motor and a servo motor to a v1 receiver and yes, it works just fine. ( I knew it would anyhow :) )
The only thing that might be a problem is that some V2 receivers are not labelled 'V2' but are unlabelled like V1 receivers are. But I'm sure that I have still done this before V2 receivers even came out and it worked.
If you want the motors to be independent you must put them on separate channels of the receiver and have both the receiver channel selector and the remote control channel selectors to the correct channels in which the motors are connector.
V2 has slightly more IR range over v1 however I have heard that v1 has a higher output to the motors.
If you want the motors synchronized for whatever reason then you can put them on the same channel of the receiver.


text:
Are there additional motors and/or sensors that can be used to extend LEGO Boost?
What extra motors and sensors can be bought to extend the LEGO Boost (17101) set?
I have heard the WeDo motors have the same connector but not if they are compatible with the Boost hub. Are they available separately?

I don't have a good answer for you in terms of what actually works with the Boost app, but the new Powered Up motors are also electrically compatible.

Lego now sell Boost compatible motors separately
https://shop.lego.com/en-NZ/product/Medium-Linear-Motor-88008

I've tried attaching one of the Powered up motors from the batmobile set (76112) This motor looks identical to me as the WeDo motor (although brickset and bricklink don't list them as identical at the time of this writing)
I could not get it to work, all profiles of the fixed build models complain that the external motor is not attached. The free build profile doesn't have any block that looks like the M-motor and using the boost motor block doesn't work either.
So my guess would be that at the time of this writing, no additional components are currently available for the Boost set...
The other way around, i.e. attaching the Boost motor to the hub from the batmobile, works...
I also purchased LEDs last saturday from an official lego store (had to ask, they had them in the back) they work on the batmobile hub, but I can't get them to work on the boost hub.

It depends on which app you want to use. My impression is that the Boost app can work with one Boost hub, one Boost motor and one Boost color/distance sensor.
If you use the PoweredUp app, you can use WeDo sensors and WeDo motors as well. But you always have to set the ports explicitely and remember that the external ports on the Boost hub are ports C and D. The WeDo motor only offers "Set power to X" functionality, no "Set power to X and run for Y seconds" or "Go to position" or "Turn for 5 rotations". This is a property of the motor, the Boost motor has all these abilities when using the PoweredUp app.
It seems you cannot use Spike motors or sensors with the PoweredUp app and the Boost hub, or at least I could not. Although you can use the Spike motors reasonably well with the PoweredUp app and the small (Bat Mobile) PoweredUp hub. The only thing that is missing then is the position readout.
I do not own a large or extra large PoweredUp motor and no large PoweredUp hub. Given that using the Spike motor with the Boost hub did not work, but using the the WeDo motor did, I am really unsure about what to expect re. the larger PoweredUp motors. I would expect the large PU hub to behave similarly to the small one.


text:
Booty Bay from World of Warcraft
I would like to build a replica of Booty Bay from World of Warcraft.
Here's some screenshots:

To make the ramps angled correctly, I'm planning on using something like part # 44570:

Can you help me find the other side of this hinge?
How do I get the platforms to curve around in in a circle to replicate the bay?
I'm considering using brown Technic axles and twine to achieve the 'rugged jungle' look. Is that a good idea? Is there a way to get Technic axles shifted to a 30 degree or 45 degree angle?

Technic has plenty of angled connectors named #1 to #6. Below is a #4 - part 42156.

However, it may be easier to use part 53585, which is an angled ball joint, in tandem with 32174, a ball socket. This allows you to create any angle you want, but those angles won't be permanently sturdy.

For creating a curved dock, you can use hinge pieces like 2429/2430, or you can connect plates with only 1 stud between them and use that as a hinge.

Thanks for the help. Those angle connectors look useful. Is there way to connect a traditional 1 x 1 round brick to one of them?

You asked:

"To make the ramps angled correctly, I'm planning on using something
like Part #44570
Can you help me find the other side of this hinge?"

Part #44568 - White Hinge Plate 1 x 4 Locking Dual 1 Fingers on
Side .

Or maybe this x 2.

White Hinge Plate 2 x 2 Locking with 1 Finger on Top.


text:
Where can I find a LEGO collection of minifigure photos?
I am looking for a collection of LEGO minifig photos - something like this, but with each minifig pictured separately in a full-length portrait. I have not been able to find such a collection on the LEGO website or elsewhere.

Here are three options that have what you are looking for:
1) Brickset has the highest quality and best organized photographs of minifigs, but they are far from complete. For example, as of this writing, the gallery does not have any of the City theme figures. The collection is growing all the time. For example, here is their collection of Batman figures:

Pros: Free to browse. Very good quality. Well-organized.
Cons: Far from complete.
2) BrickLink has a fairly thorough catalog of almost every part and minifig ever made, and they have individual photos of most of the minifigures, for example:

Pros: It's free to browse. It has almost everyone.
Cons: It's inefficient, the photos aren't all high quality, and it may not have every figure. Organization and naming are not always obvious when looking for a specific figure.
3) The Unofficial Minifigure Catalog. This is a series of catalogs that attempt to document every minifigure ever produced. It's available as a printed book through Amazon (~70 USD), as a PDF e-book through Lulu (25 USD), and as a smartphone app. Here's a sample page, taken from Amazon's "Look Inside" feature:

Pros: High quality photos, thorough, well-organized.
Cons: Costs money. Harder to search and find specific photos. Takes effort to convert to individual digital photos if that is what you need.

Brickset has a gallery of high quality photographs of minifigures from both licensed and non-licensed sets.

I second the Brickset answer - Huw began photographing minifigures only a couple of years ago. Be aware that the Brickset photos are all copyrighted since it is for use on their own site, but they are amongst the best available. http://www.brickset.com/miscellaneous/articles/minifigPhotography/


text:
Star Wars 2013 Advent calendar codes
What are the four codes for the 2013 Star Wars Advent calendar online game?

The four codes are as follows:

December 01: Y15C05
December 08: Y30C03
December 15: Y73C14
December 22: Y12C34

Day 1 is y15c05
Day 8 is y30c03

They are on the 'instruction' flap for that day.

I'd like to see pictures of that!


text:
Can I download a programm written in C# into brick?
I use C# language and http://www.mindsqualls.net/ library. But I could not find how to download my program into brick. Actually, is it possible? Or I just have to control my nxt 2.0 robot via bluetooth? Are there any languages/libraries which allow to download programs into brick or it is only possible for mindstorms nxt 2.0 visual editor?

It doesn't seem to be possible. To quote mindsqualls' site:

MindSqualls is a .Net library for controlling a LEGO MINDSTORMS NXT or NXT 2.0 robot via either a Bluetooth- or an USB connection. It is written in C# and requires .Net v. 2.0 or newer.

Which means it allows you to control your NXT brick from the PC, and from the PC only. It does not offer any possibility to create a program which you would download on the brick.
But fortunately, the second part of your question has a more positive answer: yes, there are alternatives to the visual editor provided by LEGO, and there are actually a lot of them. This has been covered extensively in another question, so I won't get into the details again, but a good start is this list of alternatives compiled by Steve Hassenplug. Note that Mindsqualls is on that list, in the section devoted to software that only runs on the PC ("remote controls").

This is not currently developed, but I think it is a good thing to check out when it is done.
http://www.dcl.hpi.uni-potsdam.de/research/lego.NET/


text:
Is there a place where you can buy single pieces of LEGO-compatible systems?
I've acquired a set of MegaBloks and was amazed at the slopes with studs on top.
Unfortunately the set is $15 and there's only 6 pieces I need.
So I wanted to ask, are there any sites like Bricklink that sell MegaBloks?
(Note: I'm talking about dozens of a single piece. No mixed bags, no used sets)

I was under the impression that BrickLink could be used for clone brands too, but I was wrong: LEGO Products Only. And it goes on explicitely to: Other brand products such as MegaBloks are not allowed on this site

Market places for MegaBlocks include:

The Bloks Forum
eBay

I didn't realize there's a forum for that, I'll try that. But I fear I won't be able to get several dozens of one piece this way.


text:
Looking for instructions for Blok Bots 9337 SPY
Where can I find the instruction manual for Mega Bloks Transforming Blok Bots set 9337 SPY?

To save future would-be answerers some time, the instructions for 9337 are not included in this repository: https://github.com/TheProgrammer163/megabloks-instructions


text:
How can I repair a red 12v train motor from Set# 7730?
I have a LEGO 7865 Red 12 volt train motor from a LEGO 7730 train set.  The motor has stopped working as it has been dropped on one of the wheels.
How can I open the motor case to effect a repair?

Do you want to open the train unit or the motor itself?

I need to open the red case of the motor itself. I think that one of the gears has been forced out of engagement, maybe the shaft is bent,

According to Bricklink,  Set # 7730 has this motor :
bb12va Electric, Train Motor 12V Modern Type I with 2 round contact holes
For disassembly and repair you can look at this large post with pictures on Eurobricks by Andromeda

Unfortunately, repairing it will not work, if the shaft is bent, as the wheel would just fall off again.

Replacing shafts is something routinely done on non - LEGO mechanisms. Why wouldn't it work here, if it's bent?


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

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

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

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

"Variables" look like this:

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


text:
Rare Lego Mursten box. Where can I sell it and what would I ask?
Found this box in a rural vintage shop in northern Sweden. I’ve come to understand these were among the first boxes of Lego sold, for the Scandinavian market. This particular one seems to be for the Swedish market, the price list on the inside is in Swedish.
This should be with someone passionate about Lego, not gathering dust on a shelf in my home.
What could it be worth, and where might I find buyers?

Your box is a 700/1 Swedish box (a 700/2 doesn't have that much blue space above and below the image).  Value depends on what is inside as well: the bricks/windows/doors, as well as if the interior cardboard partitions are still there.
Also, I know several collectors (with deep pockets) who would be interested if you still want to sell this set.

Welcome to Bricks Stack Exchange, Gary; nice to see you here!

Thanks for sharing your knowledge, Gary! Welcome to Bricks.SE!

Hey Gary, your earthlink adress does not seem to work. My reply below.

As Syberion mentioned, Gary Isztok is the authority on old LEGO sets. Mursten (Bricks in most Scandinavian languages) is the old name for the LEGO line (after Automatic Binding Bricks but before LEGO System) at a time when the product wasn’t yet globally availaible.
I would strongly recommend reaching out to him (he has a facebook page as well, look for the Unofficial LEGO Sets/Parts Collectors Guide) - maybe send him the picture of the box? He is in touch with a large group of old LEGO set collectors - this could offer you a different sales venue than putting this on eBay or a local site.
Nice find!

Thanks for the tip! Gonna sign up for Eurobricks and see if I can find Gary somewhere.

I think this is 700_2-1: Gift Package (Lego Mursten)
Source: The Unofficial LEGO Sets/Parts Collectors Guide by Gary Istock
Can't find any price information, so i would make a post on Eurobricks to determine value and/or find buyers
also i found this post about restoring a 1954 700/1 set ,
this could provide some more background

Thanks, man! I haven't been able to find a single photo anywhere online of this set. Regrettably, it does not have the instructions booklet, but (I think) most of the pieces.

Dude.
Most of the website don't even have information on it.
here's what i have found:

It's from after 1950, but before 1955.
It should be filled with individual pieces.
I couldn't find any record of selling Lego Mursten
Lego became famous after 1955, meaning this is very rare.

I also agree that you should go on Eurobricks.
I found a dude who appears very knowledgeable, so see if you can contact him.
https://www.eurobricks.com/forum/index.php?/profile/1550-lego-historian/
Here is discussion about a similar set, and then about the see further down. however, none of them have the wide blue trim like on your set.
https://www.eurobricks.com/forum/index.php?/forums/topic/77152-unknown-lego-sets/&tab=comments#comment-3011350
Here it is on Brickset:
https://brickset.com/sets/700_1_1-1/Individual-2-x-4-Bricks
Now this is a cool one, the cover for the box art is from a promotional video:
http://brickfetish.com/timeline/1952.html
If that things got instructions you are looking pretty set.


text:
What LEGO set do I have?
I gave my father a LEGO set to help with his dementia. He lost the box and directions. I don't know what the set is. It appears to be a car. There is a windshield and some wheels. It's mostly black and red. It looks like only 2 bags. I know I didn't spend more than $15 on the kit.

Welcome to Bricks.SE! The items you have described are pretty common and it makes nearly impossible to identify the set. In order to help you we would like to have pictures added with as much elements as you can collect (partial assembly is also beneficial). We'll then try to identify less common or unique elements to use them for set identification.

These parts are from:
42089: Power Boat

Keypart : 62360 - Trans-Black Windscreen 3 x 6 x 1 Curved


text:
Extra Pieces for Lego Gadgets Book
My son is having a lot of fun with the Lego Gadget set (book and bricks), but he can only build one thing at a time, and would love to have a lot more of the types of Lego bricks that came with the Gadget set. I looked on the Lego website in the "Pick a Brick" section, and wasn't able to find these bricks. Does anyone know where I can find extra Lego Gadget bricks without having to buy more of the full book/bricks set? Thanks!

Rebrickable has inventory of elements included with this book. This website has also an options to add these elements to wanted list for Bricklink as well as BrickOw. Each element has links to both websites (Bricklink and BrickOwl) so use the one you prefer to acquire elements you actually need.
Once you know the element you need you could also buy them directly from LEGO via "Bricks & Pieces" found on LEGO Support page. Although it is a bit slightly more complicated since book doesn't have a set number and you have to look up each element individually.

You could buy extra parts on Bricklink or Brickowl
for example

Technic, Liftarm
Technic, Brick
Technic, Gear

BrickLink!
Unfortunately, BrickLink doesn't currently list an inventory of exactly what pieces are included with that book. So you'll have to search for Technic liftarm or Technic gear and the like separately.
If you let us know what pieces you are particularly in need of, we can help create a wish list, which will allow you to find the cheapest store(s) (or perhaps the store(s) near you) with all those pieces.


text:
Is it possible to add the power functions to Western Train Chase?
I recently got the Red Cargo Train and it's a great Lego set but a Cars themed train going around my Christmas tree would be even better.
Has anyone gotten the power functions to work on the Western Train Chase set? Are the trains compatible with the normal Lego tracks? Is the "magnetic car connector" at the same height and compatible with the connector on the Red Cargo Train?

Also similar to the Motorising the Maresk Train question.

You could motorize the train car. You just cannot attach lights.

According to the product description on the LEGO® webn site, the LEGO® Power Functions Train Motor 88002, can be used to motorise the Western Train Chase.
The train wheels normally fit directly to this motor, so I'm sure that this train can be used on normal LEGO® tracks.
Looking at the instructions for both the Red Cargo Train and the Western Train Chase, I'd say that the magnetic couplings are the same height.

Looking at the picture it seems the wheelbase on the train motor is much wider than the Train Chase set. Maybe it's the pictures deceiving me again.

Oh, and nice find on the product description . . . that's about as good a confirmation that it should work as I could get. Interesting that it's not on the box or description for the Western Train Chase.

All train elements in the Western Train chase are standard ones, including train wheels and magnets. The construction of the front is certainly a bit different, but I've seen people replacing that by a motor (9V, actually) without trouble. You could also motorize the first waggon, which may be easier to fit a battery box.

We tried motorizing our Western Train Chase with the Power Function box as suggested on the LEGO site. It doesn't work. Their isn't even enough power for it to pull the engine by itself. The battery box itself is really heavy. I wrote my complaint to Lego. On top of this problem, we also don't have enough curved track (despite the purchase of 3 boxes of track) to make a continuous circle. They apparently only offer enough curved tracks with their $130 plus City sets... I already had a train, so was hard-pressed to buy another when all I need is curved track. Sadly disappointed in Lego, they are usually awesome.

This may sound like a dumb question, but have you made sure the batteries in the battery box are fully charged?

I haven't tried it yet, since, well, I haven't gotten the Toy Story Train yet. But with the Red Cargo Train the weight of the battery box is what gives the train traction. If you notice the wheels of the train motor have a rubber "gasket" that also helps with traction. And the Red Cargo Train is able to pull or push just about anything I put on the tracks. The magnets between cars break apart long before the power of the train gives out. I almost think you have a dud train motor.

Oh, and if you do have a dud motor I'm sure Lego will replace it. Not sure how you prove it but give them time and they'll respond to an email.


text:
Does Power Functions 88002 fit a gray-era train and run on gray-era tracks?
Is the Power Functions Train Motor (set 88002) the right height for a gray-era train (set 7745)? Does the Power Functions Train Motor run OK on gray-era tracks?

As seen in this video, it is possible to add Power Functions to set 7745 and run the train on gray tracks
Lego Train 7745 with Power Functions

photo from Brickshelf gallery
Another video
Lego 7745 powerfunktion


text:
Identify LEGO set. Star Wars?
Trying to figure out what this set is from a large bin I bought.

This is from  Set # 75076-1: Republic Gunship

Keypart : Cone 2 x 2 x 2 - Open Stud in Dark Red

Thank you.  I was thinking gunship but searches kept showing the big kit.  Appreciate your help - am new to this side of LEGO - id’ing sets, parts, etc.


text:
Please help with set identification from the picture of this part made car
please help identify the set that this car is part of.

This belongs to 41034-1: Summer Caravan


text:
Can you identify the parts for this red wizard?
Can anyone identify the hair, head, or the sapphire gem in this photo?

Hair :

Part # 16691pb01
Minifigure, Hair Long with Nougat Headband Pattern

Head :

Part # 3626cpb0931
Minifigure, Head Dual Sided Black Eyebrows, Cheek Lines, Chin Dimple, Determined / Bared Teeth with Red Eyes Pattern (Superman) - Hollow Stud

Gem:

Part # 30153
Rock 1 x 1 Jewel 24 Facet
in Transred


text:
What is this Mandalorian helmet/jetpack from?
I found this flat silver & blue Mandalorian helmet & jetpack in a mixed bag of minifigs. I'm pretty sure it's not LEGO - there's no LEGO mark or part number and the only thing printed is the number "2" on the inside of the helmet.   There is no color on the jetpack.
All the LEGO Mandalorian parts I found online have the helmet and jetpack as 2 separate parts - this one has them connected.
Can anyone find what non-LEGO set or figure this is from?  I didn't think anyone else had the rights to make Star Wars parts.

This is probably a clone branded item. LEGO uses jet pack as a separate item: https://www.bricklink.com/v2/catalog/catalogitem.page?P=64802

The clone-brands are notorious for ignoring licensing rules.  Also, the LEGO Star Wars helmets I glanced at are smooth on the top.  The dimple in the middle of your helmet could be due to lazy injection molding, which is another sign that this is a clone brand item.  That doesn't stop someone from knowing and answering, so we'll see if anybody knows.

This is part# x50px2
Minifigure, Headgear Helmet SW Rocket Pack with Jango Fett Colors Pattern
it belongs to Jango Fett (Balaclava Head)
From set 7153-1: Jango Fett's Slave I

Holy cow - good find. This was not coming up on my searches!

According to OP "there's no LEGO mark or part number", and the flashing on the visor is a lot more visible than on the pictures in Bricklink; both indicators of a clone part. Does anyone know where the LEGO marking should be on an official part?

It is real LEGO, these old boba fett/jango fett helmet and jetpack assemblies have numbers on the inside and no other markings such as the word LEGO.


text:
Identify this larger castle similar to Medieval Castle 31120
I purchased this set second-hand, and unfortunately the castle fell apart while boxing it up.  It looks similar in style to Medieval Castle 31120, especially the red and white banners, and the gatehouse above the drawbridge, but it is distinctly different.  There are more towers, including two towers with cannons atop them.  The gatehouse windows are arched rather than square,   There's a distinctive blue "shingled" roof composed of different shades of blue.

The shield above the gate has a lion's head:

Any idea what set this is, and where I can find the build instructions?

I'm baffled by this one. The brown 2x2 maraconi tiles would suggest set 10305, and the pentagonal blue roof tiles would suggest set 21325. But I cannot find a pentagonal tile with that lion head (see https://www.bricklink.com/v2/search.page?q=Tile+Pentagonal+lion ), and I cannot find any yellow 3x3x6 corner panels with that sticker/print with cracks. Can you please check if there are "lego" or "mega" markings on the bricks?

Also, part https://www.bricklink.com/v2/catalog/catalogitem.page?P=22409 is not available in grey/silver.

I think this is Reobrix 66006 European Century Golden Lion Castle

I think that's definitely it.  I never heard of Reobrix but I guess I'm now an owner.  Any idea where to get the instructions?

Instructions can be found here yourwobb
under Other


text:
What are the essential resources for learning the fundamentals of LEGO building?
After years of buying and building LEGO sets, my six-year-old son is tearing through the first level of the Master Builder Academy. He's fascinated by micro-building, and generally seems liberated after learning some of the fundamentals of LEGO design and building.
There are so many books and blogs, but many of them just show (fantastic) finished projects. I'm looking for the best published material (of any era), websites and individual blog posts that teach techniques and ways of thinking about building with LEGO -- that show and tell.

I'd particularly recommend The Unoffical LEGO Builder's Guide. It covers all of the basics and gets into many of the more complex building techniques.
If you're interested in getting right into the details, The Unofficial LEGO Advanced Building Techniques Guide by Didier Enjary covers a wide variety of building techniques and is freely available. I don't know a lot about this document, but I first came across it on The Brothers Brick.

These are great. I followed the links at the bottom of Enjary's wonderful guide and ended up at some old Brickish Association newsletters. Good stuff there, too.

I highly recommend the LEGO Ideas Book by DK Publishing. It shows several building techniques and ideas for projects and it is full of full color large pictures and building steps for several of the projects. Also, all the LEGO books by No Starch Press. They are more advanced, but with the speed your son is going he might enjoy them. Get one and see how he likes it and then get the others.

I've heard great things about the LEGO Ideas Book, but had never seen the No Starch Press offerings. Thanks much!

I second No Starch, especially the trio of books from Yoshihito Isogawa.

Isogawa's books look really great. Both of my sons love playing with their grandmother's Dacta Technic collection. She's a grade school teacher and brings them home with her for summer vacation.

Don't forget the most important resource: LEGO parts.
In my opinion, there will be a point later on where you will want to consider whether offering yet another book is worth it versus spending the same amount on bricks.
In my opinion, this is a key factor when you'll want the creative design process to successfully shift from printed documentation to your son's brain - you'll want him to be able to come with his own ideas too. Of course, this may not be for now, but don't forget to ask him from time to time if he prefers more books or more bricks.

I'm very grateful for this. And I could not agree more.   In the end, these resources are things I want to have absorbed myself so that I can help nudge him along whatever paths he opens up for himself through play and experimentation - it's to know what to put in front of him when play makes him hungry for that kind of learning. But that approach, too, can get in the way of the kind of learning you're talking about here, so I'm very glad for your response!


text:
How can I transmit horizontal torque to vertical?
I have a setup where I have a step motor which I am attaching a gear onto. The motor will make the gear stand horizontal in a small vehicle. Is there any good gear combinations of LEGO gears that can transform the  horizontal torque of the gear into vertical torque that drives the wheels of the small car I am building?
Are there multiple combinations of LEGO gears that can provide this kind of torque transmission?

you may want to omit the "gluing" part - it may have people flee in disgust and it's not really relevant to the question anyway

@Joubarc Thanks for the comment, i am doing it since regular stepper motors powered by an arduino needs to have a "starting" lego brick attached to their rod that spins

That said, this question is very similar, if not a full duplicate, of Strongest gear configuration

There are a number of ways to do this. Here is one of the easiest and earliest methods:

For that design, you'll need this part (3650):

And one of the 8-tooth gear variants:

You'll also need suitable Technic axles, Technic bricks (3700 is used above), and Technic plates (32001 in the example) to match your overall design needs.
You can also do something similar using a combination of bevel gears or double bevel gears:

Don’t suppose you can identify all the bricks in the top photo please

@marklowns I've updated my answer with part numbers and links to appropriate parts.

I'd like to cover two other techniques that work well, they both transmit horizontal torque to vertical but in slightly different ways that I believe may be useful for different situations.

Worm Gears

Worm gears are fairly small (less than two studs long). Worm gears are designed to be operated in one direction and can only be driven by the axle with the worm gear. You can get some very high gear ratios when combining a worm gear with another gear.
Knob Wheel

Knob wheels are only compatible with other knob wheels, they cannot be used with gears. They can be used parallel (like standard gears) and at 90 degree angles (like crown/bevel gears).
I find knob gears are easier and more comfortable to turn by hand and they appear to be more commonly included with recent Technic sets.


text:
Using motors to ring a bell?
I would like to create a motor set up so I can use it to ring a bell inside a small tower. Since I haven't used any of the current LEGO motors was wondering what the group would suggest.

which motor to use.
which battery/switch to use.

What I need is a simple switch with a motor. Something that I can turn off and on with out much trouble.

I'm guessing this is not a Mindstorms question. If it were, I'd suggest the original RCX motor, a loop of string around two pulleys, making the on/off button a touch sensor.

do you want one bell ping per button press, continuous ringing while button pressed/switch on, or some other pattern? The answers vary. And what bell will you use, since Lego don't AFAIK make a metal bell. Or do you mean a piezoelectric buzzer (or similar)?

@Ӎσᶎ I'm going to assume the question asker is going to use a metal bell since he/she would like to use a motor. It would be helpful to have those other points clarified.

LEGO Power Functions would probably be the most suitable option. You could use a PF M-Motor (8883) combined with a PF AAA Battery Box (88000) which has a two-way switch and is more than capable of powering four medium size or two extra large motors (each item sold separately).

As to the design, that's completely up to you and dependent on the construction of your bell tower. I'd be more capable of answering your question if you gave some more details.


text:
Where and when did the straight block letter LEGO logo appear on brick studs?
The LEGO logo that appears on the tops of brick studs has had several styles over the years. In the US, when Samsonite began manufacturing LEGO bricks, they apparently made some alterations to some of the molds they obtained from LEGO, resulting in occasional odd bricks that had both the older and newer style logos on the same brick:

This brick shows the two main styles of logo, the earlier one with thick, rounded lettering and an open O, and the later style with thinner, italic lettering that is very similar to the style used today. There have been slight variations in the size and orientation of the logo, but these are the two main styles.
I have a few pieces, however, that have another distinct style:

This is also a thinner style, but is not italic, like the modern style. The pieces I have seen it on are white plates with the modern underside - not the old waffle type.
I want to know roughly when this logo was used - It would appear to be later than the old style logo, but concurrent with the modern logo. I am also wondering how long it was in use, and whether bricks with this style logo were produced in a specific place; i.e. whether they are Samsonite from the US or Canada, or distinct to one of the European manufacturing locations.
Additional Information
The pieces I have that display this logo are white 6x8 plates with Pat Pend on the underside in block caps. This style plate first appeared in sets in 1961, and I believe by 1976 most of the Pat Pend molds were either replaced or had the words obscured. That narrows the date range down somewhat for this particular piece.
If anyone has examples of other pieces with this style logo, especially if they are known to come from a certain set, that would be helpful in answering this question.

Note: I retagged this question with [history] instead of [identification], as you seemed to be asking about the history of the straight lettering than trying to identify something. Also, very interesting question -- can't wait see some answers!

@JoshuaDrake : bounty rules aren't very flexible, you can read them in full here. In short, if there's no answer, the bounty will not be awarded or refunded.

NOTE: from 1949 to 1954 "LEGO" was printed INSIDE the brick.
LEGO appeared on the studs for the first time in the late 1954, then it was re-designed a lot during the years, becoming the stud we all know.
The not-italic stud of the photo was produced between 1960 and 1963. You can easily exclude 1963+ noticing that it's not the same exact plastic of the modern bricks (ABS was adopted in 1963).
Hope this helps.
P.S. I'm a huge LEGO collector and I'll be glad to share my expertise here and learn from other passionate people.

Thanks for the info. I'm not sure it quite coincides with this piece, however, because it's not a waffle-bottom plate, it's a circle-bottom, and the circle-bottom plates didn't come along until 1963 in Europe, and waffle-bottom plates were still the norm for this size plate in the US and Canada until the early 70s. So it's from 1963 or after. While the switch to ABS in Europe was in 1963, Samsonite still had some CA pieces in sets into the late 60s. Do you have any other pieces with this logo from a known set?


text:
How to control a RCX from a Mindstorms NXT
I have both an RCX and an NXT.
I would like to control the RCX brick from the NXT (and possibly communicate back to to the NXT from the RCX). I would like to avoid purchasing the Mindsensors RCX to NXT Communication Adapter which is no longer available in their store, and instead control the RCX via inputs to one of it's sensor ports via outputs from an NXT sensor port.
The physical connection can be achieved with the NTX to RCX converter cable but I am unsure how to control the output from the NXT sensor port to emulate any of the sensors that the RCX can recognise.
I found this post on another forum asking a very similar question, but the people who responded don't seem to have understood OP's intent, it is however worth a look for the illustrations.
This then is really a question about programming the NXT to gain fine control over the output from a sensor port to emulate a RCX sensor and if it is even possible.
I am open to solutions in any programming language/environment.

Aside from the dynamic nature of NXT programming, is there anything in particular you were hoping to gain from this method of driving the RCX?

Captain Obvious Says: "You would need to simulate input that the RCX understands. That would likely entail having knowledge of all RCX compatible sensors at the level documented for the rotation sensor as linked from the forum thread that you linked."

@JoshuaDrake Aside from the fun of the challenge of getting it to work, I was hoping to gain the 3 extra motor outputs and 2 extra sensor inputs of the RCX for 'the price of' one NXT sensor input.

@JoshuaDrake Exactly, and that is what I was hoping to find help with by posting this question.

You may have better luck over on http://electronics.stackexchange.com

I think you're overlooking a very simple yet elegant solution: connect a NXT motor to the motor port (no problem there, that's what it's for), connect a RCX rotation sensor to the RCX (again, the intended purpose), and by now you should pretty much know where I'm going with this: connect the rotation sensor mechanically to the NXT motor.
Considering the NXT motor has a good precision, you can easily you this to send messages from the NXT to the RCX; but of course you'll need to invent the protocol yourself; that is, decide what these messages mean. And you won't have feedback from the RCX to the NXT (you didn't ask for it though)

I know you don't want to purchase anything, but for reference, there is now the IR Link Sensor made by HiTechnic and sold directly by LEGO, which is presumably easier to use (and you can get feedback through it, too).
I don't think you'll be able to use a converter cable directly; you'll need to use some intermediary electronic, possibly using the I2C protocol. This prototype board solution (also from HiTechnic) should do the trick if you use one of the outputs to drive the RCX input (you can probably use an analogue one).
And if it's more ports you're after, you'll want to consider their multiplexers too.

I had considered the option of using a motor output and purchasing a rotation sensor, but as I said, I was hoping to achieve the control of the RXC, (and possibly communicating back to the NXT) by connecting the sensor ports with a converter cable.
I was hoping for tips on the programming of the NXT regarding simulating a sensor. As I mention in a comment on the question, trying to achieve control ‘sensor input to sensor input’ is partly for the fun of the challenge, but it looks like that is probably just not possible.

I fear it's not possible with just the converter cable - since the output port of the NXT will output a voltage and the input port of the RCX will be looking for a resistance (and possibly outputting a voltage of its own which will probably be a problem). Or something. But then Joshua's right, this is more a question for electronics.se

Yet another not-quite-what-you-asked-for solution: make a NXT robot that will push buttons on the RCX. Or, better, on the RCX remote if you have one. Bonus points if your NXT robot resembles a hand.

I know this is 3 and a half years late, but I figured I'd throw in my two cents.
Attach an NXT light sensor and an RCX light sensor facing into each other. You can communicate bi-directionally by flashing the built-in LEDs.
On the RCX side, this can be accomplished by switching the sensor mode between touch sensor and light sensor to passivate or activate the LED. From the NXT, things should be simpler, and even the NXT-G software has the ability to turn on and off the LED.

Interesting idea. I like the fact that this would only tie up one of the sensor ports on each controller and leave all of the motor ports free.

I've used the light sensor method successfully in several of my own projects, despite it not being a very fast form of communication (although it's much faster than the motor/rotation sensor combo). I thought about using one of the converter cables to make a direct connection, but I haven't been brave enough to try it, in fear of burning out some internal chip.


text:
Good LEGO CAD Design Software with Technic elements and animation
I'm taking computer engineering in Gr. 11 right now and our final project is to create a robot with the first version of Mindstorms. My partner and I are making a sumo robot for the class competition. We don't have the required parts at home such as gears and technic pieces and we're not allowed to take home the pieces.
We're using LEGO RCX 1.0 with 2.0 firmware and mostly technic pieces. Is there some type of CAD software that lets me test to see if the gears do what I want it to? I know LDD does this to an extent but they don't have the RCX 1.0 pieces, and placement of pieces is frustrating.
Also, I have the .dat files for LDraw, is there a way to import those parts into LDD?

Take a look at SR 3D Builder. I have not used this software myself but it looks like it may do what you need. It's free (for non-commercial use) and you can import your LDraw files.
Here is a link to some videos on YouTube
See below for the features list (taken from the website)

NEW Support for Piston - Rod mechanism
NEW Support for Linear Actuators and Shock Absorbers
NEW the Animation Console to easily create and animate your technic
models
Towball, HINGES and GEARS SUPPORT! Take a look to the Gallery  to see
what I mean
Connection Solver for quick connecting hinges and rotating parts
Support for RACKS and steering
Support for ANIMATED FLEXYBLE PARTS
Belt Generator with real connections
Now with GROUP management
New exclusive MirrorBuilding features  for quick build of symmetric
models. MUST TRY !!
Enhanced instructions editor to easily modify the order in which bricks are loaded in your model and/or take photos while building
Complex gear driven hinges support (quadrilaters deformation and
steering)
Great fully 3D building envinronment with reflection and
transparencies
You will see your model during loading time and can pause for
instruction steps
You can modify and save models (lDraw/MLCad .dat compatible format)
Fast selecting/moving/adding/removing you'll never see in MLCad
Copy/Rotation/Deletetion/Color change of single or multiple brick. Undo/Redo functionality
Real connections detection, not always the same near brick positioning
Brick selection by Block (means that solid connected bricks can be selected at once)
Grid positioning to speed up positioning of pieces
Automatic and precise positioning and orientering of most bricks according to connection detection
Automatic detection of rotation axles
You can easily load model from other known programs: it supports the
following formats

.dat files
.ldr files
.mpd files (only a few metacommand are currently supported)

How would I import pieces? I have a version of LDraw with the old technic motors but when I try to set that as the default LDraw folder, it says that there's no image folder

Never mind. I didn't set the types to display from base types to all types. I found the 9V mini-motor. But the problem now is that the model is missing its casing

@AlexYan I have not used the software, but a google search took me to this forum post:http://www.eurobricks.com/forum/index.php?showtopic=30348&st=30. The advice that may help you is "the error is generally risen when you have chosen a destination folder for the Part Library different from the default c:\lDraw and you already have the c:\lDraw folder on your HD.
To fix the problem, use the . option to choose the correct folder you install the part library to.
If you can't remember it, search your hard disk for the "Conns" folder. Its parent folder is the correct one!"

Is there an alternative for macOS High Sierra?

Edit to update: It looks like the NXT version of RDS only really supports the "Tribot", and has partial support for the "ShooterBot", but does not have a simulation of it.

I know the original Microsoft Robotics Studio supported building robots using the RCX bricks - although the latest version has been upgraded to NXT and it has simulation tools too for testing your robots prior to building and deploying your code.
As the core components should be the same (gears, beams, etc.) you should be able to get a reasonable way through testing even if the final code has to be written elsewhere.
I know some people have had success upgrading the RCX samples to newer versions of RS, but I'm not sure if anyone's tried it with 4.

Wow. Didn't know that. I'll take a look


text:
Where can I find a list of all LEGO sets ever released
Can I get a full list of every set LEGO has ever come out with?

Brickset.com is an excellent website with an inventory of sets stretching back as far as 1966.
The list is not 100% complete and the site is not an official site of the LEGO groups so it relies on contributions from fans for its updates.
The information below is from the site itself:

What's in the database? The database does not contain everything that LEGO has ever made or that carries a LEGO logo. The completeness of the database is roughly as follows:
1958-1965: No coverage. The era is too complex to cover adequately, and of insufficient interest to justify spending time researching.
1966-1969: Most regular sets, but excluding brick and service packs.
1970-2006: 98% of sets, and also many extended product lines.
2007-date: 99.9% of sets, and most extended product lines sold at shop.LEGO.com.
Although the database contains many non-brick items ('Gear') that are LEGO branded, it does not contain them all: there are too many to keep track of!

The LEGO Collector's guide is very comprehensive and has been made with a lot of collaboration with the LEGO company.
I can't vouch whether it's more complete than brickset (although I'd think so, it's extremely thick), though, and of course you'll have to buy it, but it's a very nice compilation anyway.

Page linked to is showing 'Product not available'

Although Bricklink positions itself as a marketplace for trading LEGO items it is usually used as a reference catalog for large number of items. Some of which does not exist anywhere else.
Rebrickable is another website having a good catalog, despite having focus on MOCs and alternate models.
It is best to cross-check several sources when searching for particular set or other LEGO item. My personal preference would be to use two sources mentioned here as well as Brickset suggested in another answer.