How do I remove programs from my Lego Mindstorms EV3 project?

If you click the little wrench button, you can see your programs, images, sounds and more. You just have to click on the program you do not want and delete it. Alternatively, you can hide it.

Hope it helped.

Sorry my handwriting is terrible with a mouse.


Lego Digital Designer on OS X El Capitan?

LEGO Software in general doesn't work that great with Apple computers (I a speaking from experience). Try a couple of different solutions by searching the web, and contact LEGO Support. Hope you find a solution!


Yes, TLG has acquired Bricklink. There have been multiple news, FAQ's and interviews posted with regards to a future of the website. You can read some of them on Bricklink as well as LEGO webpages. You can also read an interview with LEGO representative.
The footer on BL's webpage has been left as it was prior to acquisition. Perhaps there wasn't time to change it yet.


How to connect chain links in LDD to make tank tracks

This issue is one of LDD's most prominent shortcomings. Unlike other CAD software, the simplifications that LDD makes in exchange for ease-of-use restrict some creations from being assembled with any degree of ease. However, the treads in this model are possible to apply, although I cannot say how easy it would be to get them the way you would want.

A quick search from more experienced LDDers on YouTube turns up that the process is very redundant and tedious. Each link must be adjusted individually, and when needed, certain gears must be turned to accept the chain. However, getting the initial link on the system requires a crafty Technic device used to mount a five-hole tread to a bar suspended just above the gear in question. From this five-hole link, the smaller links can be added, as shown in this video.

I tried the process myself and while it is painfully difficult, the end result is achievable. Here is a photo with the Technic system in place, and another after I removed it and added the correct link.

Of course, I had to try this in real life where dexterity is on my side. I ran up the exact construction as I see it in your provided picture and have determined that the perimeter of this design falls just over an even multiple of links. Twenty-five links are just barely too short to connect at the ends, and twenty six is much too baggy to stay seated on the gear teeth.

For another example of adding treads in LDD, you may also want to see this time-lapse video. Hope this helps and happy building.


Where can I find a LEGO collection of minifigure photos?

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.


Motorized Excavator (8043) set alternatives

I'm afraid there is no other excavator in LEGO Technic line like 8043. It is quite unique in that it has both driving and its functions motorized. Which is why it keeps its value even on second hand market. In case your collection consist of more than 42006 set you can look into "bricklinking" 8043 set for yourself. That is, look into buying missing bricks to build 8043 set of your own collection. In fact, owning just 42006 set means you already have 45.3% of 8043.
If you are fine with fan designed LEGO model I can suggest looking at excavators on Rebrickable. All models have instructions (paid or free).
Answer to why LEGO doesn't keep same type of model for a long period of time is quite simple, I think. If you got excavator released two years ago (which is the usual life span for Technic models), you don't really need a new one. You'd probably want to get dump truck, super car, plane or some other model that you don't already have. And if you already got all the types, and LEGO keeps making sets of the same type you'd probably won't spend money on newer models, which is something LEGO doesn't want to happen.


Can you identify the set for this red LEGO snowmobile?

It's 1710-1: Snowmobile:

The chain saw piece only appears in a few sets with that color.

Here you can see the instructions.


What can I do to repair my minifigures loose neck/head joint?

In the old days, minifigures had a dab of paint on the neck. I don't know if it was for this purpose but it would wear off over time.  You can paint some nail polish or acrylic on the neck to strengthen that connection. Thin the acrylic (use water based) before applying.


Based on the occurrence of the 2x2x3 brick in white and the 16 trans-blue garage door panels, I think this is a bag from set 7744: Police Headquarters.

From the picture it looks like your bag builds the bottom right part of the station - the 2 car garages and the platform under the stairs.


Exact dimensions of studless Technic beams

Technic, Liftarm 5 x 7 Open Center Thick

Height = 7.86mm
Width = 39.80mm
Length = 55.85mm
Opening width = 24.08mm
Opening length = 40.20mm

Technic, Liftarm 1 x 9 Thick (oriented as shown on Bricklink image):

Height = 7.86mm
Width = 7.44mm
Length = 71.36mm

(measured with digital caliper, precision +/-0.05mm)


I don't think all the pieces are from one set. You have definitely got parts of the 8015 Assassin Droid Battle Pack in there (the grey and white tipped parts on the purple curved slope pieces are for sure from that set).

But you seem to be missing most of the droids (only two droid bodies and a few arms, no heads). The two Star Wars figures are from another set - the one with the black hands appears to be minifig number sw201 - Clone Trooper Clone Wars, but since minifigs can be recombined this might not be correct.

Both Stormtrooper minifigs seem to have the same torso (at least from what I can make out from the photo) but one of them has yellow hands - I cannot find such a stormtrooper on BrickLink nor a set that has both black AND yellow handed stormtroopers.

The cupola shaped bowl is from 8086 Droid Tri-Fighter (and the part is unique to this set). This is also likely where the chain of bricks on the top comes from - it forms the arch of the Tri-Fighter. The propeller-blades are part of the nose of this model.


Can anyone find a photo of the "LEGO bricks, not LEGOS" insert?

Here you go, from a scan of a 1985 catalog at Retroist. (I'm still looking for a version without the Retroist URL smeared across the bottom.)

The text reads, verbatim:

Dear Parents and Children
LEGO® is a brand name that is very special to all of us in the LEGO Group Companies. We would sincerely appreciate your help in keeping it special by referring to our bricks as "LEGO Bricks or Toys" and not just "LEGOS". By doing so, you will be helping to protect and preserve a brand that stands for quality the world over.
If at any time we can be of service to you regarding our products, please feel free to write to us.
Susan Williams

The text you quote above is slightly different and may be a variant from a different year, or perhaps it's just slightly misremembered.
It's from one of the "mini-catalogs" that came with the sets, so this was both a catalog and a box insert.


Displaying the Star Wars Super Star Destroyer in a small apartment?

By using two TV wall mounts, you could put it against the wall on its side.

This guy was able to do with the LEGO Millennium Falcon(Ultimate Collector 10179).  Here's a link to some pictures that shows how he interfaced the TV mount with the LEGO bricks.  You will have to make some modifications to the kit but that's a good reason why LEGO are fun.


Compatibility EV3 software with NXT brick - known limits?

EV3 has no support for the Light Sensor, just the Color sensor.  There is a Raw Sensor that can be used to create a Light Sensor MyBlock.  That MyBlock can then be used to create the various WaitFor, Loop, and Switch blocks using the Logic form of those blocks.

Then there is the calibration problem.  The Color Sensor block in calibration mode does not work on the NXT brick.  The EV3 can also program around that using file operations.

Finally, there is the memory problem. The new firmware leaves a bit less memory available on the NXT. The programs still need to be managed carefully to avoid using up all the memory.

Yes, you can use EV3 software on NXT bricks.  In general it is very easy.  There are some issues.


This answer is based upon the wrong assumption that Technic chain links and conveyor-belt links (a.k.a. bulldozer chain links) connect to nothing except each other.
As remarked by Ivan Sanchez, this is contradicted by this set, which uses a connection between a conveyor-belt link and a standard arm/rod.

Assuming that these chain links only connect to each other, the only way to connect them to something else, is wrapping eight of them around a standard 16-cog gear. (You can also wrap six of them around an 8-cog gear, but I would not consider that a robust and intended connection.)

Finally, the gear can be connected to a length-3 axle with stud, which in turn can be connected to the bottom of the 2×4 brick.

For bulldozer chain links, this looks like this:

Now, it depends on how you interpret the challenge: You need nine other pieces to connect the chain link to the 2×4 brick. However, many of those pieces are again chain links and there are only two pieces between every chain link and the 2×4 brick.


Is it possible to power an EV3 hub via USB?

No, the only way provided to power the EV3 is through 6 AA-batteries or the expensive rechargeable battery box. Of course some DIY solution could work, anything that provides 9V DC or thereabouts works when the voltage is applied directly to the outer battery contacts...


I need information on LEGO part #3001 in Milky White with Sparkles

According to a comment from Jan.k 1974 on the source you mentioned (in your comment to 62Bricks answer):

  The milky white brick dates to 2005 and has been been made exclusively for the Allianz Arena (Munich soccer stadium) model in Legoland Günzburg. I remember they sold spares of these in packs of 5 for 1.99 after the grand opening

This is confirmed by Maxx3001 in reply (emphasis added):

  […] that's the left brick with slight sparkle in it.

At the time of posting, ND Toys was listing these at $2.39 on BrickLink under "Milky White" with the description:

  MILKY WHITE 2X4 BRICK WITH SPARKLES (from LL park spare parts)

The arena, and the milky white bricks can be seen in this shot on the LEGOLAND website:


EV3 does not react to Bluetooth commands after 1.7 seconds

rfcomm is an old and deprecated tool, so I'm not going to try to figure out what exactly is going on. I suspect that it has to do with the fact that it treats the connection as a TTY and it is sending extra characters to the EV3 that messes up the communication protocol. I tried adding:

import tty

...

tty.setraw(f.fileno())

to the program to fix this, but it does not seem to work.

Instead, I would recommend just using Bluetooth sockets in your python program instead of using the rfcomm command line tool. Here is a working example:

#!/usr/bin/env python3

import time

import bluetooth

# change to *your* EV3 Bluetooth address
BDADDR = "00:16:53:00:00:00"
PORT = 1

# beep with 1% volume at 500 hz for .5 seconds
BEEP_CODE = b'\x0f\x00\x00\x00\x80\x00\x00\x94\x01\x81\x01\x82\x0b\x02\x82\xf4\x01'

sock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
sock.connect((BDADDR, PORT))
sock.send(BEEP_CODE)
time.sleep(1.7)
sock.send(BEEP_CODE)
sock.close()


What is the best way to sell complete used LEGO sets?

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.


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

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


Try to update your firmware via EV3 software: http://www.thenxtstep.com/2013/08/how-to-update-your-ev3-firmware.html


It looks like someone has 'reverse engineered' them from the box images in this eurobricks thread.

Hope that helped.


How can I find the unique parts in the 71040 Disney Castle?

According to the review from Rebrickable these are the parts in new colors:

Aside from the Minifigs, there are no new part designs. There are plenty of parts appearing in new colors though.

Dark Blue 3943b - Cone 4 x 4 x 2
Dark Blue 44375a - Dish 6 x 6 Inverted
Dark Blue 3685 - Slope 75° 2 x 2 x 3 Double Convex
Dark Blue 98560 - Slope 75° 2 x 2 x 3 - Solid Studs
Dark Bluish Gray 99301 - Slope 33° 3 x 3 Double Concave
White 18838 - Brick Arch 1 x 12 x 3 Raised Arch with 5 Cross Supports
White 20310 - Brick Special 1 x 1 with Scroll with Open Stud
White 19121 - Fence Ornamented 1 x 4 x 2 with 4 Studs


This seems to be item No. 2823

Technic Forklift Fork (white)

It was part of four sets:

6342-1 Beach Rescue Chopper

6545-1 Search N' Rescue

6401-1 Seaside Cabana

6663-1 Wave Rebel

All images bricklink


Why remote controls are seldom used in Technic sets?

Many Technic sets are small and wouldn't fit motors or need remote controls.

Beyond that it is an extra expense which they need to leave out to make things available at various price points.  In some cases LEGO makes the motor optional to keep costs for the initial kit lower.  And the remote control adds complexity beyond that.

But the beauty of LEGO is that you're not stuck with their designs.  You can add these features yourself if you're motivated enough.


I experimented with several different "rocket" pieces (3963) and both variations of the "tap" piece (4599a & 4599b) despite the set listing only the "b" variant, and could not replicate the issue. There obviously had to have been a "bad" batch (or "fault" as mentioned by TheBrickBlogger) of one of the two pieces that unfortunately made it to some customers.  The simplest solution, if you don't have any extra parts of this type, would be to put a tiny piece of paper or tape on the tip of the nozzle before inserting it into the rocket piece.  Another suggestion, if you have a couple of 1x1 round plates with open studs (part #85861), is to insert these into the rocket holes to hold the nozzles in place.  There is just enough room for them:

Also, as mentioned above by TheBrickBlogger, Lego would probably be more than happy to replace any defective parts you were to encounter. Even though this is an old question I hoped maybe an answer could still be useful for someone with a similar piece problem. (In case anyone noticed, I didn't have any of that piece in blue for the nose piece)


Because it takes time to write to the display. The motor speed cannot be changed until the display blocks have finished and your loop repeats.

Try this instead... create a second loop in parallel to the first that handles the display. You will need a new logic variable to send information from the motor loop to the display loop.


This is the image from the Book 2, Section 14, Page 4 on the instructions from the Lego Website - source. Does yours look like this?

To me it does look like it's not quite right - if you lift the yellow gear out, move the second part into position and then put the gear back it in it looks like it might fit, although the yellow gear wouldn't turn.

I'd advise contacting Lego support, or see if you can pick out the way the person put it together in this YouTube timelapse video.


How to retrieve a deleted program file from the lego NXT

NXT programs are compiled into a program the brick can run. It might be possible to pull the compiled code off the brick, but I'm not aware of any disassemblers or decompilers for the compiled programs.

I think your best chance at recovering the program would be to try to recover the deleted file on your PC with a deleted file recovery program.


What is the best way to store LEGO rubber tires?

I can't speak to "best". But as a point of reference, many many of my lego tires are many years old and they are usually stored on rims. The older tires were often not removable from the rims. As I rarely build cars, I take no special care of the tires, and I've found that there doesn't seem to  be any particular problems. The rubber ages over time, but this is true of all rubber in all circumstances, and the storage method doesn't seem to have affected them much. I have these large tires from an old space set from 1983

that are in excellent condition; sadly, the rims they were mounted on

were fragile and many of those are broken. But the tires are okay.


How to use the direct command to make EV3 motor backward?

The LC0() macro treats the value as a signed 6-bit integer.

From bytecodes.h...

#define PRIMPAR_CONST_SIGN 0x20
#define PRIMPAR_VALUE 0x3F

PRIMPAR_VALUE is where the 6 bits come from. PRIMPAR_CONST_SIGN means that the 6th bit is the sign. This means it has a range of -32 to 31, inclusive.

We must also keep in mind that computers use the 2's complement for negative integer values, so we can't just use 0x34 (0x20 | 0x14) and expect it to be -20.

0x20 will be -32, which is the lowest number possible. So, to get -20, we would need -32 + 12 = -20. In 6-bit hex 0x20 + 0x0c = 0x2c. But, you don't actually have to use hex formatted number. We can let the compiler figure it out like this: (-20 & PRIMPAR_VALUE). This trims the number -20 down to 6 bits. In fact, this is what the LC0() macro does internally, so we can just write LC0(-20).

If you need values larger than this range (e.g. -100 to 100), then you need to use the LC1() macro, which uses 8-bit signed integers. It has a range of -128 to 127. So, this will work too: LC1(-20).


What sets have the best price per part ratio?

Not going to argue with the reason for the request, but here are some options that give (close to) the best price per part:

Any classic brick box typically gives you a less than $0.05 per part price. Getting those on discount can get you even lower. (E.g. 10704 when on sale at WM in the US was $20 for 900 bricks - or a little over $0.02 per brick).
Special sets not for regular retail (marked as Gear on Bricklink.com) have a good price per part ratio. 40174 Chess set has over 1400 pieces and retails for $55 (~$0.04 per part). Only available at LEGO Shop at Home and LEGO stores. Similarly for the What Am I? game - 540 pieces, currently on sale for $24, so also ~$0.04 per part.
Some smaller sets, especially when on discount, also have great price to part ratio. 100-120 pieces in a $5 set gives a price to part ratio of $0.05 or better.
On the other end of the spectrum: LEGO has released quite some large sets recently with great price-per-part ratios. Sets like Destiny’s Bounty (2300 pieces for $160, Ninjago City (almost 5000 pieces for $300) and especially Saturn V (almost 2000 pieces for $120) are expensive but proved tons of pieces.
Clearance discounts (especially those of 70% or more) are great opportunities to buy high piece-count sets for little money. For example the Imperial Assault Carrier from 2014 was available at WM clearance for $30 or less, and has 1100 pieces.

Brickset has a cool feature where you can see all sets in a Theme or in a given year sorted by the Price per Piece count. First, go to the page for the year you are interested in (I chose 2017). Then use the sorting dropdown to pick “Price per Piece (US)”. You can see that this largely validates my points above. Note that the list starts with many sets that do not have a price per piece in US dollar available (promos, limited release sets, sets not available in the US etc.) You will have to scroll quite far down before the proper list starts.


How should I transport my big LEGO sets?

You should disassemble the buildings to smaller parts, then pack these parts with bubble foils. After that, you can place them in massive plastic boxes. LEGO bricks aren't really fragile.


Why do hidden Lego pieces have different colours?

Using different colors on the inside makes the instructions easier to follow. For example, in the case of the Statue of Liberty that you mentioned, if the entire model was sand-green, it would be easier to make mistakes in 1.) following the printed instructions, 2.) finding the pieces in the pile of loose elements, and 3.) attaching the pieces to the model under construction.

Remember that LEGO sets are primarily designed for children, so LEGO puts a lot of testing and effort into making the instructions frustration-free. Using different colors is beneficial even for older LEGO fans who may start to have failing eyesight and would have difficulty finding pieces and seeing the instructions clearly.

As far as which colors are chosen for the interior, they are something that contrast with the main colors of the model, easy to see in the instructions booklet, and easy to find in the pile of loose elements. Another thing that may be taken into consideration is that if the set has instructions for alternate models and what colors those alternate models would need (i.e. LEGO Creator 3-in-1 sets).


My EV3 program will not run despite clicking on the program from the brick

I don't own the EV3, so unfortunately I can't help you with first-hand experience.  Here is a link to the LEGO site containing videos with everything you should need to know to get started.
Getting Started with LEGO® MINDSTORMS® Education EV3
Based on my experience with Mindstorms NXT, if you are sure the program is done correctly then make sure you chose the correct ports that your motors are plugged into.


What is the name of the small pins that are used with small wheels / rims?

LEGO and others sometimes calls those pieces a "bearing element". This term however is not limited to just that axle.

LEGO's replacement parts service calls the holes they go into "HOLE Ø11" (possibly read "Hole Diameter 11"):

The width of the axle is roughly equivalent to the width of a "bar", like the 30374 piece used for Lightsabers as such.

None of these names are particularly satisfactory, but I'm not aware of any better names.


LEGO servo (88004) controlled by Raspberry Pi using python pigpio

I figured it out :-)
Using pi.set_PWM_dutycycle(c1, 128) # PWM 1/2 on makes it move.

In hindsight kinda obvious :)


I have an idea for a new kind of LEGO, using new types of elements

If the idea is a new kind of part, element in plastic, you may want to take it into your own hands and try to design it in a free cad app (like Sketchup, Open SCAD, Creo Elements or something). There are people around here (like myself) who have 3d printers, and may be able to suggest or try things out. You can then see if there is a market for such Lego compatible elements - see who else is interested.

Lego are unlikely to take these kind of risks themselves, but there are resources for people to try new things themselves.


Please tell me what tunnel-hull boat set this is?

After zooming the image and identifying the windscreen, I searched the Bricklink catalog and found the #4402 Sea Riders set in the list of sets using that windscreen in trans-black:

More details and instructions can be found here.


Is the EV3RSTORM from Lego Mindstorms programmable using a real programming language?

The EV3 brick runs a linux kernel so it is extremely compatible with many different programming languages. 3rd-party support packages for basically any language you can think of have been made, and most are very mature by this point. A quick google search can come up with some of these. This previous post, among many others on this site, can help point you in the right direction.

In summary, EV3Dev is always a good starting point - the framework is kind of a catch-all of the various programming languages available. LeJOS (Java) is a big step up in terms of features (and is generally higher performance than an on-brick Python interpreter, for example). The highest performance solution is probably EV3RT, if you really want to practice your embedded C/C++. But for a project as simple as EV3RSTORM, EV3Dev should be more than sufficient.


Ø is a pretty standard notation for diameter. So w/Ø 3.2 Shaft means the item has a shaft that has a 3.2(mm) diameter.


Is it possible to add the power functions to Western Train Chase?

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.


Identification of vintage sloping window piece

Must be

Fabuland Front Window Squared Small, Part x652 on peeron.com

(image source peeron.com)


How to get a random value in the LEGO Mindstorms Robot Inventor software

Under operators, there is a block "Pick Random" where you can specify to pick an integral number between x to y... x and y you can type... So for a random direction, set it between 0 and 359 degrees ...


Help identifying a black and white 1 x 1 LEGO part with clip on top

Hey there Treppy!

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

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

See ya!


Cost of different works in a LEGO set price?

The 2012 annual report on the LEGO Groups site states the following:

  Research and development activities
  Each year, new launchings account for approximately 60% of the LEGO Group’s sales to consumers. Therefore, the Group has considerable development activities, comprising anything from trend spotting and anthropological studies to the actual development of specific products and campaigns. Approximately 160 designers from about 20 different countries make up the creative core of product development that is mainly based at company headquarters in Billund, Denmark.

It's hard to quantise exactly how much of each set goes into the various different aspects you're asking about as different sets will have different margins on them. Taking some of the numbers in the report however, you can see things like:

On Revenue of 23,000mDKK:

6,800m was spent on "production costs" (about 30%) - these are defined as "raw materials, consumables, direct labour costs and indirect production costs such as maintenance and depreciation, etc.". These are further broken down to include:

4,400m on Raw materials and consumables
1,500m on Licence and Royalty expenses

1,200m was spent on "other operating costs" (about 5%) - these are defined as "[including] royalty and research and development costs". This is further broken down to include:

451m on Research and Development

6,100m was spent on "Sales and distribution expenses" (about 27%) - these are defined as "costs in the form of salaries to sales and distribution staff, advertising and marketing expenses as well as depreciation, etc."

In terms of where parts are made, this answer covers most of it, but as you rightly note, Minifigs, and some painted parts now come from China. In terms of R&D, this answer talks about how new pieces could come about.

Updated: Some of the actual break-downs in here come from the "2012" columns in the 2013 report.


Round 2x2 piece that goes underneath plate

Well, that tile wouldn't go underneath a plate. But a 2x2 round plate with rounded bottom has often been used in official sets to allow vehicles (such as boats) to easily slide over carpet, and might be just what you're looking for.


When using pi * distance between wheels/tracks, how do I measure distance between wheels?

This formula will need the lateral distance between wheels, i.e. the distance between left and right wheel, not the back and front wheel.

motor_pair.move(8.1 * math.pi / 2, 'cm', steering=100)

The steering=100 parameter means that the wheels will move in opposite directions. For the 8.1 value, one wheel will move +12.7cm and the other wheel will move -12.7cm. That is half of the circumference of a circle with diameter of 8.1 cm.
Now to the question: exactly what point of the wheel you should measure in left-right direction. It should be the point of the wheel that does not slip when turning - the outer edge will slip one way and the inner edge will slip the other way.
Measuring between the middle of the wheels will be a good first approximation. However the exact value will depend on the tire texture and their mounting alignment. You can test how exactly it turns 180 degrees and fine tune the value to larger or smaller.


How do you support upper floors in tall buildings?

Extra support in form of pillars/walls underneath (remember that also weighs something and as such should be supported) is one (and probably the most widely used) solution, another would be to build the floor thicker, and depending on how weak the floor is and how much it has to support yet another solution might be to just not care.


How accurate is the ultrasound sensor when moving?

Short answer: The ultrasonic sensor is perfectly accurate while moving!

A regular NXT robot will move at a maximum speed of several meters per second (usually about 1 or 2 m/s max.). Ultrasound, on the other hand, travels with about 330 meters per second through air. So during the "snapshot" the ultrasound sensor does (basically it sends a ping, listens for the pong-echo, and takes the time difference), your robot appears to be frozen for this brief moment.

So this is why, whenever your ultrasonic sensor makes a measurement, you get a freze-frame snapshot of the current distance to the nearest object it detects. In reality, the sensor sends out pings all the time during default operation, and you just get the very latest measurment -- but essntially, this feels the same.

Since the ultrasonic sensor is digital and offers its data via the I²C protocol, this is where the main latency comes from. On the other hand, you shouldn't poll (i.e. read out) your sensor too frequently, if that is what you're worried about. In several tests we've concluded with hundred NXT kits, that a polling rate of 50 Hz (50 times per second, delay of 20ms between each poll) does work perfectly with no problems at all. When you're using NXT-G, you shouldn't worry at all: You won't get values faster anyway. When you're working with other languages, and you feel your ultrasonic sensor doesn't work so well in a tight loop with constant polling, try to insert this little 20ms break!

Far more important are the objects you try to detect. This is due to the wavelength of ultrasound. You can't detect objects with dimensions of just a couple of centimeters.

The US works best when facing walls, perpendicular to the sensor
It has big problems detecting furr, carpet- or cloth-like surfaces (the ultrasound doesn't get reflected)
It has big problems detecting smooth surfaces, facing the sensor at skew angles (not 90°) -- the ultrasound gets reflected away
It has problems detecting round objects (e.g. a water bottle or a football) accurately. The ultrasound gets reflected too widely, so you'll see the bottle or ball "bigger and wider" than it is in reality.
It will miss tiny objects

The first rule is, as always: Experiment on your own! For more resources, try the LEGO NXT Hardware SDK or at least the pictures in this german paper, pages 24, 27ff.


How to make Mindstorms respond differently, depending on which sensor is triggered?

I believe one possible answer can be found in the sample program for the color sorter in the Mindstorms control software. The technique that kit uses is to create a series of nested if/then loops:

if (Color == red) {
  //do red things here
} else {
  if (Color == blue) {
    //do blue things here
  } else {
    if (Color == green) {
      //do green things here
    } else {
      if (Color == yellow) {
        //do yellow things here
      } else {
        //default actions here
      }
    }
  }
}

Using this as a template, you could use a structure like:

if (Touch Sensor 1 == Pressed) {
  // Special Action 1 (i.e. turn left)
} else {
  if (Touch Sensor 2 == Pressed ) }
    // Special Action 2 (i.e. turn right)
  } else {
    // Default Action (i.e. drive forward)
  }
}

Hope this helps - I don't have quick access to the Mindstorms environment right now or I could set up a quick screen shot. I can only refer you to the ColorSorter program in the samples.


Not yet. You can try RobotC that's pretty similar.


Program for NXT golf robot not looping properly

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);


You probably don't need it, but the LEGO Education NXT 2.1 Software is still for sale through LEGO Education (at least in the USA). They do not advertise and upgrade price, but it does not hurt to ask.
The Energy Meter blocks are available for download on the LEGO Education website. I went to http://education.lego.com/en-us/downloads and checked the box "Blocks" under "Download Type" and it shows up in the list. It does not say if it is for NXT or EV3 though. Also, I found this for the NXT Temperature sensor.
I would not recommend using the EV3 software for programming the NXTs. There are a number of limitations, such as lack of support for 3rd party sensors and lack of support for Bluetooth. Also, I understand the programs take up much more memory this way.


I am not aware of any sellers that do this, but if you like to assemble discontinued sets, bricklink
has a feature that allows you to do this using bricklink seller inventories. Just look up the set on bricklink, add the Inventory to your wishlist and review which sellers have the pieces you need, then order them.

Go to the "Wanted" tab on Bricklink: http://www.bricklink.com/wantedAdd.asp
Then select the "Part Set" tab and fill out the item number of the set you are looking for (you might need to do a Catalog search to find out this number). Pick the options you want, check the "Set Minimum Qty" option, and "Submit for Edit". You will now have a broken down list of parts that you can edit (for example, replace original parts with proposed substitutions, this is useful when your set is really old and the original part is difficult to get, but a more current part exists that likely has better availability). Add this to your Wanted List and you're ready to go.

Alternatively, many old, discontinued sets can be bought, in box, on ebay and bricklink, but depending on the rarity and popularity of the set you might be paying a significant premium.


Java BufferedImage with Lejos NXT: Java Heap Space

I'm a little puzzled by how you are getting these results, but I am assuming you are getting an error when you run the equivalent of nxjc and nxjlink on a supported platform. i.e., you are probably invoking nxj -r ...

Furthermore, I am assuming you are basing these commands on a recent Java compiler from Oracle; version 7 or 8.

First of all, it is my understanding that java.awt.image.* is not even present. The example showed here should not even compile because the only AWT classes we have access to are java.awt.Point and java.awt.Rectangle.

Furthermore, only some of the javax.microedition.lcdui API is implemented, so you should check the documentation to see if Image is supported in the manner you want. So, for example, ImageIO is not present.

So, the example programs you show here are not going to even compile (never mind link) with the as-shipped latest version of leJOS NXJ.

At any rate, the size of the heap for leJOS is basically all of the RAM on the brick, but it is shared with the stack and static RW memory. But I'm not convinced the message you are seeing is related to the leJOS VM runtime heap, but rather the heap of the thing that is trying to create the classes and link them into the "TinyVM" before sending them to the brick.

We don't know because you have not described exactly how you are getting this message, with what command(s), with the full output of the exception(s)!

So, if you want to solve this, we need:

The platform you are running leJOS on.
The output of %LEJOS_NXT_JAVA_HOME%\bin\javac -version (assuming Windows; you know what to do for OS X or Linux)
For that matter, what is %LEJOS_NXT_JAVA_HOME% or ${LEJOS_NXT_JAVA_HOME} set to?
The output from the command you are running. Try capturing what comes out of nxj -v -r Main
The version of leJOS NXJ you are running

Place this in the body of your question, please.


Why are some of the supports on bottom of a lego piece hollow, and other are solid?

Almost assuredly it is a move to reduce the amount of plastic used. It may seem inconsequential, but adding up hundreds of millions of these makes for a ton of savings. The same thing goes for the brick walls, but not in the case of the ones you show here. I haven't seen it in any 1x bricks, but in most 2x bricks these days, the walls are a tiny bit thinner (perhaps the cause of many complaints of translucency) but with little ridges there the studs touch to keep clutch at appropriate levels. One might guess that this new wall would reduce the number of times a brick will accept a stud before losing reasonable clutch power.


How can I find the value of a LEGO set over several years?

Not sure about several years, but Brickpicker covers one full year. Here are the stats for the Green Grocer, for example:

Or the ones for the UCS Millenium Falcon:

And so on, you get the idea. They have more and other stats, too — e.g. the following quick overview for every set:

They pull their data from eBay, through some third-party tool they licensed.

Now, I think they only let you look up like three sets at a time — then you have to register. But the registration is completely free. They cover their costs via affiliate marketing, i.e. links to Amazon and the like.

They can also sync your account with (i.e. import your sets from) Brickset and Rebrickable, but I never gave that a try. I'm not much of an investor anyway, just your typical AFOL. In fact, according to them, the prices for some of the discontinued sets I still have unopened have actually plummeted.

I suppose if I were in for the long haul, I would just take a screenshot of their stats every twelve months and then string them together in GIMP.


How to remove an unslotted length-2 technic axle from a one-way axle hole?

The method I use is not as "purist" as Wrzlprmft's, but it also works. Wrap the exposed section of the axle in a piece of cloth (a T-shirt works well), then gently grab the cloth-wrapped axle with pliers and pull out. The cloth is to prevent any marring of the axle piece, and it also provides a good grip for the plyers. Needle-nose or other small pliers work the best as they give you the most control for manipulating small LEGO pieces.


How important is a center differential on a 4WD model?

Well, the center diff allows the front and rear axles to turn at different speeds, which is useful to put less stress on drivetrain parts that are constantly moving around. However, for a Lego model it is probably not required, since it most likely would not move at speeds required to necessitate one. Building one in would add realism, but you would need to keep in mind that with a center diff, the torque all tends to go to the axle with the least traction.

EDIT: Why the front and rear axles sometimes move different speeds, why it matters

Imagine a four-wheel-drive vehicle, with a center diff, moving at a decent speed. It encounters a bump in the shape of a half-sphere, approximately 2 inches across, on the right side. The right front wheel will encounter the bump first. As the vehicle drives two inches over the bump, the rear wheels both travel two inches. However, the right front wheel, following the shape of the bump, travels pi x 1 (the radius of the bump) inches, or approximately 3.1 in. Since the right front wheel covered a farther distance than the rear wheels during the same period of time, it went faster than they did. This translates to a slight difference in speed between the front driveshaft and the rear one, which is easily handled by the center diff. However, the same scenario applied to a vehicle with no center diff could bend or break the driveshaft, as the rear section and front section try to go at different speeds. At LEGO scale, however, this difference could probably be absorbed by the flexibility of LEGO parts without incurring any damage.


Information on this large beige motor w/battery box?

It's the main module from Record and Play (set 4095):

This part was only included in this set released in 2003. The part contains several motors and some electronics that allow you to record motor movements and then play them back.

Pressing the red button would let you record movements for a maximun of 20 seconds by adjusting the motors and the green button would play back the last recorded movement.


Is it possible to repair LEGO box creases?

Since creases in cardboard are not mere folds but instead constitute real damage to the box, I don't think you can undo a crease to make it look new again. Even "sort of" straightening it out will not do much good for a box - the damage (compacted internal structure) will remain visible and the area will remain a weak spot for further damage to develop. Finally, the printing is likely also damaged in the creased spot and this damage will show clearly if you manage to straighten out the crease.


Why does BrickLink append a -1 to so many set numbers?

TLG hasn't always been particularly careful about their set numbering, so the community has taken to adding -1 to the end of the set number to handle cases where there may be duplicate set numbers used by TLG. For example, here's what we refer to as 8858-1:

And 8858-2:

As others have pointed out, this also helps to track minor adjustments to sets (re-releases, box differences, inventory adjustments, etc). Bricklink maintains a list of sets that are similar and have the same official set number but which are assigned unique suffixes for various reasons.


Where can I find this piece in LDD V4.3.11?

I tried in version 4.3.10. The element is present both in standard and extended mode.
I updated to version 4.3.11, had to update anyway as 4.3.10 apparently wasn't supported anymore and only worked offline.
In the standard mode, I can confirm element 14704 is not present.
However, if you switch to extended mode (Main menu -> View -> New themes -> extended), it's present.
Unfortunately the extended mode let's you build in colors that might not exist...
I hope this gets addressed in a next update as to me this seems a standard element.


What do the terms "vintage" and "classic" actually mean?

The two biggest themes to be called "classic" are "classic space" and "classic castle" and refer to the period when these themes were first introduced.

Brickset subthemes reflect this: Classic Castle covers the first yellow castle and accessories, from 1978 to 1983. I'd tend to include the new series from 1984 myself, since there wasn't much to speak of before that, but maybe I'm just wrong or maybe that only shows that there is no actual definition of "classic" to speak of.

The brickset subtheme for Classic Space covers the period from 1978 to 1987, with one extra set in 1988. Afterwards, they started naming themes, such as Futuron or Space Police, so you could say that the classic period covered the space sets before that. A lot of fans seem to limit themselves to the "blue with gray wings" livery of the first space sets, though, and do a fantastic job of it.

There's also a castle fan community site called Classic-Castle.com and several Classic space fan community sites, such as Neo Classic Space (notice the blue-and-gray again). I think there was once a classic-space.com but that doesn't seem to be operational any longer.

That's for Castle and Space; for more info you can also consult the Brickipedia pages for Classic Castle and Classic Space.

By extension, I suppose all themes from the same period qualify too. Bear in mind that this period (the eighties, in a nutshell) correspond to the period when most of nowadays AFOLs were kids, so they have fond memories of the sets they had or drooled about. But as far as I know, none have devoted fanbases; and there are no corresponding "Classic City" or "Classic Technic" subthemes on brickset.

Saying "Classic Jack Stone" will probably get you very puzzled and/or angry looks.


LEGO guide shows the orange blinking appears when batteries are flat.

.

Have you tried using fresh batteries in your train?


LEGO tracks are 12mm high, train wheels go below the true height of the track and so in reality only add 7mm of height.
The structure gauge (also known as clearance) tolerance will obviously be a lot lower than real life. You could perhaps get away with 1/3 a brick clearance but having at least one or two bricks height clearance at minimum is best.
Here are a few measurements for different types of trains.

Model
Name
Studs
Centimetres
Inches

Amtrak Superliner
17.9
14.4
5.7

4551 (Pantograph extended)
16.3
13.1
5.1

Double-Stack Cart
12.8
10.2
4.0

Early Steam Locomotive
12.4
9.9
3.9

I have used Bricklink Studio to render and calculate these measurements. The models used can all be found in the model library.
Dimension and weight statistics for models can be displayed under Tools > Mode Information so if you can find a model for the train you are interested you can check using this software.


How can I separate 1 x 1 round from boat mast base 4 x 4?

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


Can I download a programm written in C# into brick?

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").


Where can I find the LEGO fire dept. logo in high resolution or in vector format

Going on advice from InkBlend I converted the logo to a vector graphic from a sticker sheet scanned in for the 7945 Fire Station set on BrickLink.

I used VectorMagic to convert the file and automaticaly create paths. The SVG vector file can be downloaded here. If you don't have an image editor that supports vector editing, you can also download a high-resolution PNG graphic (267.33 kB).

You could also try scanning in a sticker sheet from a set that has the sticker. With Illustrator, Photoshop or any other similar image editors, trace around the design using a pen tool and fill in the colours. Using the scanned image as a reference.

If you're having trouble finding a suitable image, I would also recommend looking at the LEGO City product page for wallpaper downloads and illustrations.


That is Jack Stone, a figure AFOLs love to hate.

from 4617-1: Dual Turbo Prop


Directly from LEGO:

Pick a brick

Third party:

bricklink.com

bricklink is cheaper in most cases, on both you can choose and buy only the pieces you really need.


How create a custom Roller Coaster? Where I can get the track pieces?

You can buy tracks directly from LEGO. You go to LEGO service web page and follow steps below:

Click on BRICKS & PIECES just below the banner
Then BUY BRICKS
Provide your age and location (please be aware the list of countries where LEGO is shipping to is limited)
On the left side you have an option to chose parts from particular set. In this case use "10261".
You might need to click "Show more" a few times to get to individual pieces you need.

Note. 10261 Creator Roller Coaster set does not have every type of element within track system. You may use part numbers provided below to look for individual tracks using the option on the right side in Step 4.

Alternatively you can purchase all the pieces on Bricklink. Look for:

25061 - Train, Track Roller Coaster Curve, 90 degrees
26559 - Train, Track Roller Coaster Ramp Large Lower Part, 6 Bricks Elevation
26560 - Train, Track Roller Coaster Ramp Large Upper
Part, 6 Bricks Elevation
34738 - Train, Track Roller Coaster
Ramp Small, 3 Bricks Elevation
26561 - Train, Track Roller
Coaster Ramp Steep, 6 Bricks Elevation
25059 - Train, Track
Roller Coaster Straight 16L
26022 - Train, Track Roller Coaster
Straight 8L


Where can I find documentation on the LEGO Wireless Protocol for Powered Up devices?

LEGO calls this communication protocol the "LEGO Wireless Protocol" (LWP). The documentation is publicly available at https://lego.github.io/lego-ble-wireless-protocol-docs/.

There is also a GitHub repository that provides the source of this website at https://github.com/LEGO/lego-ble-wireless-protocol-docs. Because of this, it seems reasonable to expect this documentation to evolve over time.


By number of distinct colors, what official LEGO set has the most pieces?

I have a few:

3 colors: 2882 parts for 3450
6/5 colors: 4502 parts for
40179. Note: color count depends if you include brick separator
as a part or not.
11 colors: 2428 parts for 10181
15 colors: 2455 parts for 2000431
23 colors: 7513 for 75192
37 colors: 2613 parts for 2000430


How to build a steerable remote-controlled vehicle with just 1 motor?

This can be done without a caster wheel as well:

Start out with a three wheeled vehicle, with two wheels in the front and one smaller wheel with less traction than the front wheels in the back. All wheels need to be fixed.

One of the front wheels is attached to the motor. This might need to have some gearing to get an appropriate speed.
The other front wheel is unpowered but can only rotate forward by adding a ratchet:

The back wheel is unpowered.

Driving forward the vehicle will more or less move straight, guided by the rear wheel.
Driving backwards the ratchet will engage, stopping one wheel. The vehicle will now turn.


How well does the new interior lighting system intergrate into a new build?

Considering the new PF lights are more compact at the point where the light is, I would say it's easier to integrate in creations. They do have a big block on the cable where the two lights are separated, but that leaves you more liberty compared to previous 9V lamps for which you had to have the cable connector on the lamp itself, which took quite a lot of space.

As such, you may be able to fit PF lights in tighter places, and have less constraints on the orientation (I'm thinking ceiling light with the bulb directed downwards, for example).

By the way, that's an area where a lot of LEGO fans are more willing to toss purism aside and use their own leds and cabling, which can easily be done without damaging a single brick, takes less place, and usually costs less.


What are the curve radii for the curved slope pieces?

These curves have been approximated by the contributors to the LDraw project. You can download free software to view and use the part files, from which you can approximate other points on the curve. For example, here is an LDraw part file shown in "wire-frame" mode:

LDraw parts are drawn in increments of the "LDraw Unit" (LDU) in which a standard 1x1 brick is 20 LDU wide by 24 LDU high (not including the top stud). By examining the part in an LDraw viewer, I was able to establish the coordinates of some of the points on the curve:


Building a more-efficient water propeller?

The LEGO RC boat by Slewentogzz claims to have a top speed of 3 km/h, it uses a custom propellor built out of Technic parts.

The actual rudder parts appear to be Technic Panels #87080 and #87086. These panels are very common and are available in over 60 sets.

There are two more parts in a similar design (#64683 and #64391, they are one stud longer each so you can make a slightly larger propellor.

Images: Slewentogzz Lego Creations

Video: "Lego RC Boat with custom built propeller (3,0 km/h!)"


Does anybody have pictures of a minicon?

These three images are from BrickCon 2016.
I've rearranged certain portions of this moc to make a 4 foot square section of Emerald City Comic Con 2016. It's on flickrvid ECCC

This image is from BrickCon 2014 and was taken the night before the public viewing... It was almost set up. Once the other builders added their mocs, it was.


It's one of the Indians from the Western theme, from 1997:
http://brickset.com/minifigs/ww016/Indian-Tan-Shirt-Quiver


That's a pretty vague question, but here are some general resources on city building:

Rebrickable has a large selection of MOCs. Browse through it and see if you can find something fun there.

You can look through all of the official City sets. Brickset is a good place for that.

Twinlug has a fun Micropolis standard you can use to build a large layout together with other fans.

When you get serious, you might want to get into the modular buildings - it has become a pretty common standard to build for as well.

Hopefully that gives you a start.


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

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

based on Ladder and Staircase 7X4X6 in Reddish Brown.

It also contain the Plate 4X4 in green, and the door and wall pieces.

Bag 4 is from 9526-1: Palpatine's Arrest

Based on Corner Plate 6X6X45° in Medium Stone Grey and Brick 1X2 M. 2 Holes Ø 4,87 in Bright Yellow.

It also contain the red 2x6 and grey  1x8 technic pieces


Difference between The Lego Group and LEGO Systems A/S

LEGO explains its ownership here https://www.lego.com/en-us/aboutus/lego-group/ownership.
Also available from that page is the annual reports. Last year's annual report has a list of all the various subsidiary names by country (see last page of https://www.lego.com/en-us/aboutus/lego-group/annual-report/). It appears 'LEGO Systems A/S' is the company name for the Denmark arm. So there are a lot of names and nuances and it depends in what context you want to refer to it - and how exact you need to be. The LEGO Group would be the right name to use in most fan (rather than business/legal) contexts.


Tree Palm Top was used as lanterns in old pirate sets, for example 6285


Differences between EV3 Gyro and Hitechnic Gyro

IMO there are no advantages of the old Hitech gyro:
The most fundamental difference is that the Hitechnic Gyro is a analog (ADC) device while the EV3 Gyro is digital (serial). This makes the Hitechnic Gyro badly suffer from drift and oscillating offsets (both at stand still and by changing output voltages caused by electricity consumers such as motors switched on/off) which has to be filtered off. Digital sensors like the new Lego gyro are not affected by these interferences - basically - at all.


Duplo rail accessory compatibility with older trains

Physically, these parts are compatible. They simply rest in between the rails. Various elements have made use of the space between the rails for years, such as points:

Older trains don't have any way to understand the function elements and respond accordingly, but they won't derail or anything like that.


Need help identifying these 7 lego pieces!

Minifigure, Footgear Roller Skate
Leg Skeleton
a scarf to be worn around the neck for minifigs, I can't remember the name
No idea
Minifigure, Footgear Ice Skate
Carrot Top / Twig
Technic, Link Tread


I have found some torsos from a collection in my dad’s loft; can you identify them?

The last one is from Indiana Jones
Part# 973pb0452 - Torso Indiana Jones V-Neck with Bow and Flower Pattern
It appears in Marion Ravenwood - White Outfit


The RCX system provides a certain average voltage level (via PWM) to the motors. This means that speed can vary based on load, and may even vary slightly from motor to motor. Power will also vary based on load, as a motor with more load will draw more current if voltage is held constant.

If you're interested in specifics, you can measure the voltage and current on the motor lines with a voltmeter, or view it on an oscilloscope if you have one available. From there, you can calculate the power (P=IV) for your setup.

The RCX system does have a rotation sensor if you need to be able to make specific speed and/or distance adjustments. In later systems, additional data lines were added to the communication protocol to allow motors to have embedded rotation sensors and allow precise speed control, but this is not possible with the RCX system.


Help identifying a bag containing many white plates


Differences in varieties of 2x2 tile ( 3068 3068a 3068b )?

The difference is actually explained within the naming, which comes from Bricklink, a place where people buy and sell LEGO items around the world. In cases like Bricklink, especially with AFOLs, it is necessary to know which exactly parts you are dealing with.

During the years LEGO has been upgrading parts, where Tile 2 x 2 is not an exception.

Initial version is 3068a, which comes without a groove - its side is same like any other plate - smooth. While it may look great in an assembly it is hard to remove - there is no real gap between a tile and other part it is attached to. There's also no stud on top you could somehow use to take things apart (for example, with brick separator).

So LEGO eventually updated this tile (Bricklink denotes it as 3068b) to include a small groove, which helps with disassembling tile from other bits without much effort.

Bricklink uses "Undetermined version" for cases where seller can list an item without specifying which actual type (with or without a groove) it is.

I don't have any old parts on hand to take a picture, however you can see both tiles used in digital form are different. Green one doesn't have groove and Yellow one has.


Set Identification: 2011 set, bag 3, #135149

This bag is from 75092-1: Naboo Starfighter

Based on

4655280: Plate 4X4 W/Angle
4260934: Left Shell 2X6W/Bow/Angle,Inv


How can I make controller ports round for my "Lego Gamecube"

Perhaps something like this using 1x4 arches could work?

This does work out to being 2 modules too wide for 1:1 scale with a GameCube, but the trade-off in accuracy may be worth it to you to get the round ports. It appears to be only 1 module wider than your current design.
Here's more detail of the build steps:
Step 1

Step 2

Step 3

Step 4

Step 5

Final Build


Sending information from one EV3 brick to another EV3 brick

Currently, RobotC does not support Bluetooth messaging[1] or USB daisy chaining[2] LEGO MINDSTORMS EV3 programmable bricks.


Even though support has ended, the LDD software still works. Alternatively, you mention LDraw but LDraw is only a catalogue and a standard - there are different software packages that allow you to draw on top of the LDraw catalog such as MLCad and LEOCad - have you tried these to see which one works? I use MLCad extensively - it looked daunting at first but the tutorials at http://www.holly-wood.it helped a ton - worth spending a few hours doing those tutorials.

As per @Philo's suggestion: another program worth looking at is LDCad, which promises to be more convenient and more powerful than MLCad or LEOCad.


Lego Mindstorms Ev3 home edition on Mac OS Mojave bug - bricks sometimes go blank

I contacted Lego support and they got back to me with a fix, which worked great.  It also has greatly improved the performance of the application.

  For this issue fix, please install Mono for Mac OS found at the link below:

  https://www.mono-project.com/download/stable/

  and choose Mono 5.10.1


How can I build a LEGO structure based on a real building?

Take pictures of your building, of as many sides as possible
Take measurements or find blueprints of the building. Length, width, height, height between floors, size of balconies etc.
Convert these dimensions to LEGO dimensions. For this, figure out the scale you want to build in first (e.g. 1:40, which is "minifig scale" - but check out this post for some caveats). You can use Sariel's calculator to find out what this means for how many bricks you need.
For best results, design the whole building in LEGO Digital Designer (LDD) or LDraw first. This will save you from making unnecessary brick purchases before you have finalized your model
Get a brick inventory from LDD/LDraw once you have your final model.
Use a service like Bricklink or BrickOwl or Lego's own Pick-a-Brick to buy the bricks you need in the quantities necessary, after accounting for all the bricks you already have. Alternatively, you can look at other available sets to see if some of them carry the bricks you need in large quantities - this might be cheaper (you could even sell the not-needed bricks back via BrickLink etc.).


Identify white element on back of Apple monitor

If I understand which part you are referring to, it looks like Hinge Plate 3 x 4 Locking Dual 2 Finger (44570) to me.

It's tough to tell for sure what it is connected to, but it is probably Hinge Plate 1 x 4 Locking Dual 1 Finger (44568)


Lego RCX to NXT converter cables not working properly with EV3

These cable don't have anything connected to pins 5 or 6. This causes the software running on the EV3 that detects which type of motor is connected to think that there is nothing connected. Since it thinks nothing is connected, it periodically resets the output port which turns off the motor.
To work around this, the unregulated motor block needs to be called in a loop with two different speeds (e.g. 100 and 99) to keep the motor running. Each time the requested speed changes, it resets the device detection timer that would stop the motor.
Some people who don't mind cutting the cables have added resistors to the wires connected to pins 5 and 6 to simulate what a real EV3 motor looks like. This allows the unregulated motor block to able to be used as expected.
Here is an example of how to do that. (Although I would wire it up more like the actual EV3 motor schematic using 3.3kΩ resistors. Pin 5 to pin 4 via resistor and pin 6 to pin 4 via resistor. But if the other method is known to work...)


Is it possible to remove a parted out set from BrickLink inventory?

Part out the same set, but with a negative quantity.
This does indeed work, as I have solved this very problem using this solution in the past:

This is a screenshot of my Part Out Log, and you can see I've accidentally parted out 10 sets twice. Then I've reversed the second part-out.
You can see a list of every set you've parted out (after mid-2009) and the quantity in your Part Out Log.


Is there a hobbyist standard for Trains track modules?

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


Are the plastic bags inside the LEGO box recyclable?

According to this bricksetforum thread (and also true of the LEGO sets we have around right now) the LEGO bags are #5 plastic which is accepted by Whole Foods and some municipal recycling services.
This thread
has interesting commentary on bag packing considerations.  Not surprisingly LEGO Group is optimizing for efficiency and dependability.  The bags and their weight also affect the QA process which includes weighing the bags.
2021 update - the future is getting here
LEGO is reportedly moving to paper bags.  This is a double win of going with a renewable resource and wider recycling availability.  LEGO themselves have a page on their sustainable packaging that says:

We will begin to test paper bags in our boxes which means goodbye single use plastic and hello recycling bin! First, we will trial recyclable paper bags that are made from Forest Stewardship Council certified paper. They will be designed to help children understand the importance of recycling and ensure they have the best possible play experience. Our new bags will be phased in over a four-year period from 2021.


Is it safe to overload LEGO train motors?

What could be considered a safe limit that motors can endure for an
  extended period of time?

Their rated voltage.

Motors are designed to operate at their rated voltage indefinitely, or until they wear out, whichever comes first.  Exceeding this voltage means you shorten the life of the motor.

Your big enemy is heat.  At some point, the amount of heat generated by the windings in the motor will exceed the ability of the motor to dissipate it, and the wire in the winding will melt and break the electrical connection (usually at the point where the wire is soldered to the commutator).

The point at which failure or excessive stress or wear occurs is influenced by many factors, including the amount of current driving the motor, the speed at which the motor is turning, the amount of load the motor is driving, the ambient air temperature, etc.  These variables make it difficult to predict a safe voltage above the rated one.

In addition, over-driving motors in this way makes them inefficient; speed increases are offset by higher losses due to back-emf, limiting the additional torque, so driving motors this way eats batteries fast.

Last but not least, overdriven motors are a safety concern.  The paint covering the windings can catch fire and burn down your house; you have to watch such experiments very carefully.

If you really want to increase the power, your best bet is to choose a motor with more torque, so that you can run it at its rated voltage.


What is part number for this yellow cylinder?

That would be 75535 Technic, Pin Connector Round 2L without Slot (Pin Joiner Round)

There's a newer variation on the part which has a slot, but you can tell the difference by the hairline crack in the picture.

62462 Technic, Pin Connector Round 2L with Slot (Pin Joiner Round)


Compatibility between vintage (80s/90s) Technic and current parts (motors etc)

The motor you have linked is indeed quite old and as far as I know, not compatible with anything newer. Seeing that it works with simple DC current, it wouldn't be hard to construct a converter cable, but it is still some work (especially reducing the voltage from 9V to the 4.5V required by this motor).

The next generation (9V system: large motor, micromotor, mini-motor, buggy motor) has much better prospects regarding compatibility, as they can be used with the voltage regulator, the control center with the recording function, dumb battery boxes, first generation RCX controllers, cybermaster and code pilot units and there are even converter cables for the PF system. There are even light and sound elements for this system and the cables are nice and simple 2-wire ones with brick-compatible connectors, carrying anywhere between -9 and 9 volts.

The PF system has been in use for the last several years and is widely compatible even with 3rd party accessories like SBrick or BuWizz. The cables here have additional wires for controlling servo motors and the connectors are stackable, but proprietary and only partially compatible with LEGO bricks.

It is not yet clear if the even newer Control+ system will at any rate be backwards compatible at all, but knowing the LEGO community, it is only a matter of time.


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

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


Difference between Linear Actuator vs. Linear Actuator Mini

The biggest difference I can think of that would impact my choice would be that the standard linear actuator is much more sturdy.

The standard linear actuator has a metal pole and is very rigid.

The mini linear actuators are made all of plastic, wiggle quite a bit, and whatever mechanism is inside will skip fairly easily.


Principles of D.I.Y. Minecraft microworlds

There are two key ways these can "fit together":

Most obviously by size and connectors - all the worlds are built on 4 6x6 plates, and have a 1x2 with cross-hole brick at the bottom in the centre of at least two sides.
By theme (or in Minecraft terminology "biome") and features (forest, mountains, etc).

In terms of the four sets released, only two meet both of those:

The Village
The Forest (Ideas)

These both use the same shades of grey for the underground sections, and similar colours for the overground sections (greens, browns, etc.).

The other two sets represent completely different areas ("dimensions") within Minecraft accessed via special portals - there's no way to walk from a Forest biome to The End or Nether, so from a connecting point of view, neither of these really "connect" to the others.

So to create your own cells you'd want to follow the following guidelines:

Choose a Dimension (Overworld, Nether, End)
Work with 6x6 plates (or variants/multiples of)
Use a scale of 1x1x2/3 for most blocks (i.e. 2 stacked 1x1 plates) which can be capped with a 1x1 tile, for deep sections bricks can be used
Underground is typically 4 bricks tall, overground can be taller
Transition between biomes nicely (Forest - Beach, Forest - Jungle, etc.)


Why do the tubes in the Seattle Space Needle Architecture set need to be cut?

This happens in Technic models as well, at least for pneumatics tubes. I would tend to assume it's a simple production issue or simplification - as this requires less work from LEGO.

That way, they only need one length of tube per model, instead of having one part ID for each of length of tube. Considering LEGO wants to control its number of elements currently in production (it's not infinite), this makes sense.


You will find most LEGO pieces, including those that are specific to the Bionicle theme on Peeron.
For example here are your particular mentions:

Technic Bionicle Weapon Flame Sword 2 x 12
Technic Bionicle Weapon Blade 12L
Technic Bionicle Toa Inika Zamor Sphere Magazine
Technic Bionicle Weapon Midak Skyblaster with Black Housing
Technic Bionicle Rhotuka Spinner Ripcord 12L with Hand Grip


I was able to integrate this into a research project applying context free grammars:

This is not a polished software package, and the design is a bit esoteric given that I started with the goal of applying context free grammars to a practical problem. Hopefully there's something in there that may be useful to someone. :)


I have an idea which was actually from JKbrickworks. Here is the MOC that uses it and here is another MOC of his that uses it.
Here it is step-by-step:

First, we have a plain old technic brick.

Now there's an axle stuck through it. That connector at the end of it is what I will use as the lever to turn. You can use whatever you want.

These connectors on the other end of the axle are supposed to lift the parts up and down, up and down, up and down. Using bigger ones will push them higher, but make sure that their ends are rounded.

And obviously, we need to add bushes. But we're still not done!

Buncha brickwork...

A 1x1 studded beam was added so that we can loosely hold a beam up above.

A non-friction pin is added.

A 1x5 beam was added, but I should actually use a 1x6 beam instead, which is fixed in the next images. What's the beam even doing here anyway? It's going to act as a guide for the axles that will sit above it.

Same process is gonna go on again. Note that I used two 1x6 beams in half because they didn't seem to exist in full. And yes, the technic beam must be laying on the lifters like that. I had to update it.

Almost done! But there's more...

More brickwork...

Now we have a technic plate with holes to stick axles through.

And of course, we stick axles through, you don't have to use plates like I did. And make sure that they are loose enough and rest on the beams. This is also the time when you can turn the lever to see if the axles pop up and down, up and down, up and down. If they don't and get stuck, try turning the lever the other way. At this point, we are almost, almost done.
The only thing left is to find a way to attach this minifigure shield to the axles. I don't have any solution for this unfortunately.
The final result should look something like this:

Update:
We've thought of using bars to connect the fountain parts, but we've discovered a few downsides and problems with that.
The first problem is that the plate with holes in my build is placed in such a way that it's not exactly aligned with the beams below, increasing the chances of any bars being placed on top slipping off.

The second problem is that the bars are noticeably thinner than the size of the holes in the plates, which leads to some pretty bumpy performance, as shown below. Your bar will tip around and possibly even slip out.

The build can be improved to reduce the chances of such things happening by doing the following:

First, let's remove that plate to make our additions.

Now we will have some off-set studs in order to align the plate.

And now we put the plate back, in a better position than before.

Now it's not as likely that the bar can slip off the beams. Don't you notice the difference?
We can reduce the chances of that happening even more if necessary by adding more plates with holes to restrict the bar from slipping, like so:

Alright. Now about the fountain spray problem.
The bar for that piece you're interested in is positioned in a rather odd way (if you're wondering why then just look at some of the thumbnails of 76108) like this.
But don't worry, I have a solution for this. Just stick the bar holder /w clip on top of the bar and attach the fountain spray part, and you'll be done! Easy!
The completed model should now look something like this.
Download link (click the button in the upper right corner)


Question about the lantern pieces in the Winter Toy shop set

I don't have this piece to check this assembly physically myself to confirm. However, the same design has passed TLG design review not once, but twice: first with 10199 set you mentioned in 2009 as well as 10249 six years later, which is updated version of 10199. So I'm rather confident there is no flaw.
Looking at the picture it seems like Cylinder Hemisphere 2 x 2 with Cutout sit underneath the round plate's ridge, thus making it stable.

I have built this assembly virtually. Here hemisphere is placed above  round plate's ridge intentionally, to show the fact that hole diameter is smaller. Thus, by placing hemisphere below round plate (as it is shown in instructions) will block it from moving vertically.


The finish of the piece and the numbering scheme reminds me of Megabloks pieces, but it is far from a 100% sure, definitive answer. After half an hour of searching on Google and on the Megabloks website, I have seen no such product that would contain this piece, but based on its apparent age, this information is still not decisive.


Where is this round blue BIONICLE figure from with circular hands and a transparent head?

The set in question is 8562 Gahlok. It's missing the legs and parts of its head.


Looks like it is this Universal Set with Flex System. Looks like the instructions can be had fairly cheaply.


Parts/Step not fitting ( technic / gear not aligning)

Problem solved. I had a part wrongly fitted.
both parts look similar ( black gear wheel)...one(part#6012451) is smaller that other(part #4177431).
back on track now. .. :-)


What is the easiest option to start making instructions?

After testing several software (and figuring out quite a few are not compatible with each other), I tested Leocad, and was able to easily create models and generate instructions.

In Leocad 0.82, going through "Print Preview…" and then printing to PDF generates simple and clean instructions.

http://raphink.github.io/lego_models shows the results I got with that method.


This is Technic Gearbox Half. It's very easy to find by searching "technic gear" on BL.

The item number is 32166, and it was available in the early 2000s (specifically from 1999-2002).


2016: which Power Functions for controllable car?

If you have no technic and no power functions you will need to get quite a lot. You could buy small technic sets to get enough parts to build the moving parts and you your current collection, or buy a big set and just add power functions to it. The Customized Pickup Truck is a good starter set that has all the right moving parts, but pretty much any Technic truck/car contains steering and a drive chain that you can attach a motor to.

For steering I recommend the servo motor. As a kid I spent a lot of time making cars that would lock left or right but not flick back to exactly straight afterwards.

For propulsion you have a whole array of motor options, the biggest and strongest (but also the slowest) is the XL motor. I've seen the Customized Pickup Truck converted to full RC using two M motors.

One IR receiver can control two wires so if you're only thinking about propulsion and steering one will do.

You'll need a battery pack. I prefer there one that takes AAs because years from now AA battery will still be purchasable and may be even longer lasting, plus you can keep spares near by, as opposed to the Lego rechargeable battery which will wear out over time and not be available forever.

And finally a remote. The speed remote lets you control the speed of the motors, not just forward/backwards at a fixed speed. However you'll need some extra parts to make left/right steering make sense on there. The other option is  the basic IR remote. Either one can control two functions.


Actually, I have had some success through trial and error and found that a Spybotics remote will do the trick of controlling the RC dozer.


How can you estimate the value of a LEGO collection?

This isn't an easy one: collections can vary considerably in value according to the rarity and desirability of their component parts. There are several approaches you can take to valuing a collection, but it really depends on how much work you're prepared to put in.

Of course, the only true indicator of anything is the amount that someone is prepared to pay for it. However, as a lot of people are buying and selling LEGO, we can get a lot more specific than that.

The Stupidly Fancy Method

Now, at the extreme end of the spectrum, you could go to the trouble of cataloguing every component in the collection and coming up with a price for each piece - based on BrickLink or something similar. There are 3 problems with this approach:

Prices on BrickLink are a fair guide, but remember that these are selling prices, which may not match the price that someone is willing to spend. For common components the prices are probably about right, but for rarer ones the vendors may be asking unrealistic prices.
It isn't all about the parts. Complete sets may be worth more than their component parts, especially if boxes and instructions are present and in good condition. Mint, unopened sets are often worth more than opened sets, but how much more depends on the set.
For anything but the smallest collection, this approach is prohibitively time consuming for us mere mortals.

The Easy Way

At the other end of the spectrum is another approach: weigh the collection, and base the price on weight. People often sell by weight on eBay, so by looking at a few listings it is fairly easy to come up with a figure for price per kg (or lb). The problem with this is:

There is a fairly wide variation of prices on eBay.
It doesn't take into account complete sets, manuals etc.
Some parts are quite heavy - motors, weights etc.
This approach doesn't take into account the difference between collections with lots of small parts vs lots of larger ones.
Some parts are worth more because they're rare or particularly desirable, e.g. minifigs tend to be more desirable than regular bricks, star wars components are more desirable.

Despite these issues, this general approach seems to be fairly common on eBay. They might sell for more by parting-out, but the effort and time involved just isn't worth it.

My Way

Of course, you can do something in between.

So, here's what I would do if I were selling:

Guess the value.
Figure out your price / kg by looking at recent sales on eBay.
Pull out any complete sets.
Pull out any remaining paperwork and heavy stuff (motors, battery boxes with batteries in).
You should be left with a pile of bricks. Pull out all the minifigs (don't worry too much if you miss a few, and ignore their accessories) unless they're already holding them.
Weigh the remaining loose bricks, and use your price / kg to value them. If you think there is non-LEGO in there (megablocks etc.) either pull them out or reduce your price a bit.
Weigh the complete sets. Use your price / kg to value them and then add a % based on how desirable you think the sets are. Castle, train, space (inc. StarWars), pirate and technic tend to be worth a bit more.
Assign a nominal value to each minifig. Regular city people are worth quite a bit less than "interesting" figs. Starwars are favourite, followed by other "fancy" ones. (If I were selling, I'd probably sell the figs in separate bundles).
Add this lot up.
Compare the difference between the guess you made in 0 and the answer you got in 7, and pick a price somewhere in between.

Of course, if I were buying I'd knock 20% off this price and insist that the seller do the same!

Notes on Pricing

When setting a price, consider the following general rules:

Although the age and rarity of a set or component has some relation to its desirability, they are not the most important part of price.
Quality of the parts matters a lot. Scratches or other marks lower price considerably. For example, I've got some old bricks from the 60s that are really poor for building because they're not made from the same plastic as newer bricks. As a result, people don't seem to want them, despite their relative age.
"Cuteness" of models matters a lot. Some of my oldest sets are quite rare, but they're also quite boring (e.g. sets of roof tiles). As a result they're no where near as valuable as a relatively common but fun set from the same era.
People like figs, so the pre-minifig era sets are not so desirable.
Many buyers like sets from their childhood, so nice space-themed sets from the late 70s - early 90s generally do well on the second-user market.


What are the best sources of information for upcoming LEGO sets?

The LEGO store calendars are available online about a month ahead of time. It lists the upcoming promotions, specials, new sets, store events, etc. They are the exact same ones as what you would get in the mail. You can find them in the right-hand side-bar here: http://stores.lego.com/en-us/

As far as going as far ahead as the following year, you are not going to get official information on this, as LEGO doesn't reveal their future sets more than a few months ahead the most. You will have to follow rumors and leaks, which may or may not be correct. I would suggest that you become a member of either Eurobricks or Brickset and follow the discussions on possible upcoming sets.

Also, it is a good idea to follow LEGO news at the beginning of the year, as new LEGO sets get revealed at the various toy-fairs in January/February. Pretty much all LEGO fansites will closely follow the news coming from these events. The sets displayed are usually go as far as the summer, but they will not include the large exclusives, which usually get revealed separately.


Which buildings in the LEGO Island video game were based on real-world sets?

While a few are indeed sets there are some I can't recall seeing (such as the Information Center, which was probably too specalised to deserve it's own set).

As already pointed out the Pizzeria set is very similar to the one in-game.

The set "6598 Metro PD Station" was the in-game police station, incuding jail. The helicopter could be build during in a minigame in the police station. Accessories like the box of donuts and flaming pizza were not included in the set.

The set "6334 Wave Jump Racers" was the beach lookout where you could start the jet-ski race around the island.

The Lego race cars in the game were similar to these sets: 1477, 1990, 1517 and 1612. I can't find the racetrack start itself but it was in keeping of the Octan branding that was used.

I thought the ambulance was set 6666 but I was wrong, the one in-game had a much longer sloped roof.

The Bank (which was always closed?) I can't really remember anything along the lines of, and I think the houses up on the hill were just generic lego houses.


What set is this LEGO pack from? Grey pieces with 10x10 octagonal plates in grey and green?

LEGO Kingdoms - King's Castle 7946.

I see the green and gray plates and other pieces the look like that


These parts are used to hold the cards upright as shown in the instructions:


Are there any existing (or upcoming) aftermarket PoweredUp hubs?

BuWizz has announced the BuWizz 3.0 Pro which has Powered Up compatible ports.
The product page says:

Expected Delivery: End of March 2021


Please Help Identify These Star Wars Sets

1.Set# 75172 Y-Wing Starfighter.

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

3.Set# 75003 A-Wing Starfighter.

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

See ya Fabian!


What sets are these pieces from, rock platforms and walls with large cannons

It looks like you have some Mega Bloks sets.

I can't say for sure if these are sets you have, but I found similar pieces in these sets:

Dragons Battle Gate

Portal of Fire

I don't know of any resources for non-LEGO instructions.


"Unable to compile" error code with LEGO EV3 Arm Robot Program

I think the key phrase is "A My Block cannot contain a copy of itself." Look in the "INI" My Block for another copy of the "INI" My Block and delete it.


How to Decipher Lego Building Instructions Filenames?

After emailing back and forth with LEGO, I think I have an acceptable answer:

Example:

BI 3005/48 - 7594 V 110 2/2 - Download size: 5.94 Mb
^   ^   ^      ^   ^     ^                   ^
1   2   3      4   5     6                   7

Stands for Building Instructions
A number for internal usage by different LEGO teams.

You'll see that many different sets share this number, and all the numbers are fairly close (generally in the early 3000's).  My guess is that it has something to do with whoever drafted and finalized the instruction manual.

This number shows the number of pages in the manual.

When the number is show x+y, that means x building pages, and y instructional pages (e.g. what to do with bricks, or what bags are needed).

This is the set number.
This number refers to the page format of the instruction manual.

V29 means ISO A4 paper format.
V39 means letter paper format.
Other Vs (like 110, 140, etc) are different file formats.  LEGO said "those are the types of versions throughout our country that we ship to".  I'm guessing that they are related to the official formats for the manuals that are included with the kits.

The booklet number:  x/y means x booklet number out of y booklets.
The file size of the instruction in megabytes (not megabits, as it would seem to imply).


How to prevent my connected axles from falling apart?

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

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


Overview of online LEGO discussion forums?

The main discussion boards for teen and adult LEGO fans are as follows:

EuroBricks Forum - this is one of the oldest and most established LEGO fan forums with a huge number of discussions going on at any given time. You can find everything here from news, to custom building, to contests.

Brickset Forum - this is the second largest LEGO forum, mostly focused on collecting LEGO sets.

Reddit Forum - this is a very active forum in the standard Reddit format, focusing mainly on breaking news, shopping deals, and helping out those who are new to the hobby.

BrickLink Forum - this is another very old forum, mainly focused on buying and selling LEGO.

BrickPicker -  for those who are into buying, selling and investing in LEGO. It has set & build reviews, availability information, deals on buying LEGO etc.

There are many other, smaller forums specialized on a specific topic (like customization, castle building, Technic building, LEGO Star Wars, etc.), but if you participate in any of the big ones mentioned above, you will be well connected and informed.


What lego set is this? Possibly a pirate ship?

It's a ship alright.. a heavier than air airship: Wright Flyer.

Quite a fun, if rickety. build.


What are the dimensions of a LEGO brick?

This image shows the dimensions in LEGO Units. 1 Lego Unit is 1.6mm (the thickness of the plastic wall).  In those units the stud's diameter is 3 (= 4.8mm).


One way you could achieve that is to use Minifigure, Utensil Posing Stand, Bar with Hollow Stud with the bracket you've mentioned. Not entirely sure of an exact angle, but it looks to be close to 45°/135° angle.


A quick search found these two video's of AT-RT's in green

https://www.youtube.com/watch?v=c0sFAreiaPc

and

https://www.youtube.com/watch?v=Cbc_k_GwfRw

this AT-RT is also very nice and greenish (no video)

https://www.flickr.com/photos/legoarts/4917477074/in/photostream/


Colored balls detectable by EV3 color sensor

There is an interesting discussion on this on the lejos.sourceforge.io forum.

  the calibration values for the NXT sensor are set in the factory and seem to be different for each sensor (which implies that there must be a reasonable amount of variation between different sensors). On the NXT the RGB values are true raw values and the calibration adjustments used to identify Lego colors are made in the leJOS driver.

But on the EV3 there is no calibration, and the sensor RGB mode

  is not well documented and was not exposed at all in the first version of the Lego software...So the bottom line is I doubt if anyone outside of Lego (and maybe NI) knows if the RGB values are raw sensor readings or if any sort of calibration data has been applied

So it doesn't sound like you will have a consistent set of data anyway - I'd suggest just seeing what coloured balls you can get cheaply and just trying them.


What year did the minicon "micro BrickCon" first appear at "BrickCon"?

In the blog of Tom Aplhin he mentions regarding Microscale

  Steve Oakes, a long-time LEGO builder in Seattle area started a tradition 4 years ago to re-create the BrickCon Public Convention at a smaller scale. His display is called “Micro BrickCon”

(Edit: The conversation between Tom and myself was in a loud room with lots of activity. He is correct about everything except the year.)

After building and displaying an 8.5 foot stern paddle wheel ferry boat at BrickCon 2011, I decided it would be easier to build smaller MOCs. I kicked the idea around for a while, and then came up with the concept of making a micro-con. Mariann Ansunuma, former miniland builder at Legoland, and current maker of awesome microscale Lego jewelry, liked the idea and took me under her wing. I built 2 tables, displays and minilanders to display at BrickCon 2012. I was very pleased when Mariann brought along a third table, displays, and minilanders to add to mine.

After the initial Micro BrickCon MOC was displayed, Mariann, who travels to various cons with her vendor booth, took her portion of the MOC and introduced it to cons across America. It has since become a theme featured across N. America, Canada, Germany, and Australia.

In 2012, the MOC was just a MOC. However, micro BrickCon was so well received, in 2013 it became and remains it's own theme. In 2012 7 builders contributed one thing or another to make the MOC better. In 2013 and 2014, 22 builders contributed, and this year, 2015, 29 builders joined in.
                                                                 -Major Stackings


Megabloks need help identifying what set

This is a part of the tower from
Set # 3618 : Privateer's Lighthouse


How is the neck of the green velociraptor 10757 connected?

Looking at inventory for Velociraptor, included in 10757 set you've mentioned, there is a Technic Pin. Since all of the limbs have half of the pin molded into the parts this leaves us with Technic Pin that is used to connect body with a head piece.

Better pictured by this step from LEGO building instruction (thanks Syberion for the tip):


Trouble with 42110 Land Rover Defender transmission

Just figured it out by rebuilding it. I had pressed the "walls" of the transmission too much, resulting in very high friction.


MindSqualls - can I connect more than one NXT brick using USB?

I’ve had a quick look through the MindSqualls code and it looks like you can. I cannot test this however as I don’t have two kits.

Note: I believe it is preferred to NxtBrick class rather than McNxtBrick class as the latter is for a special program used for precise control over the NXT motors.