# Question
Title: Looking for instructions to build a hobbit hole without 'custom set pieces'
I've searched on 'rebrickable' for anything hobbit related, but I can't find it.

This is what I'm thinking of:

> 79003-1: An Unexpected Gathering

I'd rather buy a large bucket of 'free for all' lego bricks, that can be made into the Hobbit hole, but I've not found any instructions.

Are there any instructions for a similar structure?

# Answer
> 4 votes
I have an alternate plan you might consider:

* Reference: here's the entry for that set on Brickset
* It looks like there aren't many custom pieces used in this set, as seen in the parts list
* You could download the actual instructions for the real set, and then just swap out some pieces, removing the color combinations that you don't have

I hope this helps in some small way!

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Tags: instructions
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title: How much torque can a lego axle handle?

text:
# Question
Title: How much torque can a lego axle handle?
from to this question, it seems that the gears are stronger than the axles, which begs the question of how strong are the axles? if you connect one of the stronger motors, such as say the buggy motor:

which according to philohome can produce 14N\*cm of torque with an adequate power supply, is this enough as-is to break axles? what if it's geared down 1:2? 1:4? (such that it turns slower with more force), at what point do you risk breaking axles? (or more likely, at which point will they start to bend and lose strength)

# Answer
> 4 votes
In this forum thread I have found the following tidbits:

* "We all know that XL motors can twist axles to their breaking point" This means 40 Ncm, according to Philo.
* "If you're looking to get max torsional stiffness, then stacked 2L axles + connectors would definitely be much stiffer in torsion than a single long axle."
* Axles can twist without breaking in two

Besides these, I couldn't find an exact number.

# Answer
> 2 votes
I have never broken an axle. That's despite dealing with some rather hefty forces that dwarf any LEGO motor. I made a flywheel (around 800g and 8cm radius) and spun it by hand up to 1,000 RPM (through a gearing system and a monstrous handle). That's 28 joules of kinetic energy there. I then released it all into a single wheel (with more gearing up), with the drive passing through A SINGLE axle. The axle was only slightly bent, and could easily be twisted back.

On another note, I often use torsion bars as shock absorbers in my vehicles when I need a compact double-wishbone suspension. A 1.5kg vehicle provides enough weight to twist eight 7-stud axles by around 5-10 degrees.

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Tags: technic, motor, power-functions, gears
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# Question
Title: What's the maximum pressure one airtank can withstand and how to tell its limit?
I bought a airtank and using it to support many v2 pneumatic cylinders, while I'm using a v1 pump and one motor to pump air to this air tank. Since another airtank or a lego pressure gauge is very expensive in my area, I'm trying to continue with my current installation. I also noticed that the speed of the motor is getting slower while air continue being pushed in.

But is there any way to tell if the airtank is at its limit, and can it explode by using just one pump and one motor? And what's the pressure limit approximately if you have a gauge to measure? Thank you very much!

# Answer
> 6 votes
You will not destroy the air tank using standard LEGO components. I don't know what it's structural limits are, but I can tell you that the weakest link in the pneumatic system in my experience is the connection between the rubber pneumatic tubes and plastic inlets. Under high pressure, the tubes will simply pop off before any of the components will actually break.

I believe that the most pressure you are going to be able to achieve using standard LEGO components is around 40psi. All of the components can easily handle this pressure.

If you'd like to do some exploration of this on your own, you might want to get your hands on the pneumatic pressure gauge that has been available in the LEGO Education line:

If you really want to know the maximum pressure limit of the tank itself, you'd probably need to somehow attach it to real compressor and wait for it to break. I like my pneumatic components too much to do this myself. :)

# Answer
> 1 votes
The pneumatic system's limit is three bar (40psi). After that point, the hoses will pop off the ports. I don't think you could explode the airtank very easily with a real compressor. My guess is that it would start deforming around the 5-10 bar range, and only explode once it was bordering on spherical :P.

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Tags: technic, pneumatic
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title: What are the torque limits of gears?

text:
# Question
Title: What are the torque limits of gears?
I am using Lego in the classroom to introduce students to geared machines.

As part of this I am asking them to design a winch, using a small 1.5V DC motor and a collection of the common Lego gears, i.e. the 8, 16, 24 and 40-tooth spur gears, and the special worm gear.

Based on rough back-of-the-envelope calculations, I will require about 5 N.cm of torque at the winch drum.

* Do I have to worry about breaking any gears due to excessive torque?
* Do I have to worry about gears slipping (skipping teeth) due to high torque?
* Has anyone performed experimental (destructive) tests to quantify the maximum torque these gears can withstand? Order of magnitude is OK - will the gears break at 1 N.cm, 10 N.cm, 100 N.cm, ... ?

# Answer
> Do I have to worry about breaking any gears due to excessive torque?

LEGO Gears are one of the strongest LEGO components. When you apply great amounts of torque, they may slip or grind, but never *break*.

> Do I have to worry about gears slipping (skipping teeth) due to high torque?

If you apply high amounts of torque, your gears will slip. This happens even with moderately high amounts. They may also slide down the axle and grind the side of the other gear, or the axle.

> Has anyone performed experimental (destructive) tests to quantify the maximum torque these gears can withstand? Order of magnitude is OK - will the gears break at 1 N.cm, 10 N.cm, 100 N.cm, ... ?

Your gears will withstand the torque quite well - it's probably other components, like the axles and beams, that will give way first. Don't worry about breaking the gears - the worst situation might be that an axle or two might bend.
> 3 votes

# Answer
Simply put, they won't break. I've put LEGO gears through everything I could and they were fine. That includes spinning an 8-tooth gear at around 80,000 RPM (sustained for only a second or two) via a flywheel-based stored-energy device. I've driven a 9lb vehicle with about 40 gears in the drivetrain, and none broke.

Slipping teeth is rather common. As a guide, if you sandwich spur gears between two beams or bricks with holes, you're not going to grind them. I would trust that for 100Ncm or more. If you are going to put the structural beams further away from the gears, the torque limit reduces. You can increase it by adding bushes (to stop gears from sliding along axles) or by adding short beams that span two axles - this stops the axles from bending and disengaging the gears.
> 0 votes

# Answer
### If anything breaks, the gears won't primarily be the problem.

> Do I have to worry about breaking any gears due to excessive torque?
>
> Do I have to worry about gears slipping (skipping teeth) due to high torque?

I have seen gears get to *nearly twenty* N.cm without issue, other than slipping along the axle, (easily fixed with bushings), or skipping, (easily fixed by super-gluing your chassis pieces together.)

However! Not all gears are made equal, and I have broken a couple of (gear) teeth in my day. Your 40-tooth gears might be in for a rude awakening as to their structural integrity under high torque.

This can be easily solved, I think, by changing the gear ratios, which will be a great lesson for your students, how big gears driving small ones can make things more efficient.

---

The "real problem" will most likely be the bricks. Bricks don't stand up to torque as well. If you compress a brick too far, it *will* snap, despite how tough they normally are, or at least chip.

This may be a hard issue to solve, not to mention the other "real problem" of the binding power of bricks to each other. Fortunately, there is a solution! You just may not like the fix.

Superglue is tough. It stand up to a lot of pressure. As I said in the first bit, super-gluing your chassis-pieces together may be the only way to handle a challenge like this, if your students have trouble with structure.

So say you don't like ruining your pieces' chance of use ever again, like me. I suggest that you look up good ways to structure a Technic chassis, and if a build is iffy, tell them what needs to be fixed.

But for argument's sake, I have tried many things like this, and everything was fine. Just make sure that somehow, every piece stays in place.

But only if you're using LEGOs for the chassis at all!
> 0 votes

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Tags: technic, gears
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# Question
Title: What are the significance of 3 marks that appear on the back of base plates?
I am trying to find out the significance of 3 marks that appear on the back of base plates.

There are 3 circles in a row. The first contains numbers 0-9 in increments of one with a small arrow pointing to a number. The second circle contains numbers 0-50 in increments of 10 with the same kind of arrow. And the third circle contains an icon that looks like a dog tag.

# Answer
I think that this is a production code similar to the seal codes on other sets (e.g. 24R5 for the 24th week of 2015), and you need to add the number from the first dial to the number of the second dial to get a week number, and the Q "dog tag" indicates the production facility this came from. It's missing the production year though, perhaps that was not needed or has been encoded somewhere else on the baseplate.

**UPDATE**: The year of production is printed in the center of the single digit dial ("11" in your case) with one digit on each side of the arrow. So your base plate was made in 19Q11, which is the 19th week of 2011. This code seems to be on other LEGO elements as well - for comparison here is a picture of a LEGO Mindstorms EV3 tray from set 45544. It also features a Q, and has a "15" printed in the center of the single digit dial (the full code is 17Q15):
> 3 votes

# Answer
### At first, these look like regular old LEGO IDs. But they can't be...

These include:

* Part ID: The type of part it is
* Mould ID: The Mould that printed it
* Copyright: The LEGO copyright statement.

Obviously, there is no copyright statement in this piece, so we'll have to rule that out as a possibility for the "dogtag."

We might be out of ideas as far as lego meaning here...

### But Wait! Lots of plastic products have these "clocks" on the bottom!

Check out this link on SE: Seasoned Advice!

> This is the date the item was manufactured. The upper dial gives the year, the middle one, the month.

Perhaps this isn't particularly correct, because of the difference in increments, but we might be a little closer. Is it possible that LEGO is just following the plastic printing norm?

Or it possible that these numbers are made to be *combined?* Maybe these indicate a year or some other time, but maybe...

### Maybe they're related directly to the plate piece ID somehow!

As for the 'tag, your guess is as good as mine.

### But here's a thought:

> The bottom indicator could be a mold identifier, and in some cases, it might be a shift indicator

Perhaps this is some sort of grahpic ID instead of a number that indicates something about that kind of mold, or even something about LEGO itself.

I spent maybe 5 minutes staring at my baseplate collection, and they all seem to have one, including the vintage models, so I'm going to lean towards a "kind of mold" instead of "a particular mold."

### So here's the TLDR.

Though the internet and my LEGO friends don't know, I think we can narrow the possibilities down considerably:

* The markings mean something about *when* the piece was made.
* At least one of the markings means something about *where* the piece was made.
* The markings mean something about *what* the piece *is* (ID.)

*The fun is in the search!*
> 1 votes

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Tags: piece-information
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# Question
Title: How come themes like BIONICLE can afford so many new parts?
LEGO is quite economical about introducing new parts in its standard sets. One reason is they need to fit in the system, but the other is that hard tooling molds for production is quite expensive.

How come for a theme like BIONICLE they are able to introduce sometimes over a dozen new parts in just one set?

# Answer
> 1 votes
Bionicle sets don't actually make as many new pieces as they did.

Typically, new pieces are weapons or heads, and LEGO company is already cool with green-lighting those. (They're sorta important.)

Gen 1 Bionicles did, admittedly, have a lot of new pieces, but Gen 2 sets, you will frequently find, try to recycle concepts and pieces, just in different colors or with different printing as much as possible.

Hero Factory was pretty revolutionary, with pieces that connected to themselves, (ball *and* socket,) but for that those were made, you'll see them incredibly often as staples of new sets. That particular kind of new-piece binge shouldn't happen again for a long time, if ever.

I don't know about a *dozen* pieces in *one set* though. You'll often find that "new" pieces are just old ones recolored, reprinted, or recycled.

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Tags: bionicle
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# Question
Title: Do any of the KRE-O Transformers sets actually transform?
KRE-O, a LEGO-compatible brick toy, has several officially licensed Transformers models. I have two of the smaller ones and they do not actually "transform" - you take them apart and put them back together in a different form.

Do any of the sets use model functions to provide transformation, or are they all simply different models using the same bricks?

# Answer
There's an almost 20 minute video about the kre-o Optimus Prime at youtube where pretty much everything is shown in detail - except the transformation itself. I'm really sure that if this was possible without disassembling and building it from scratch then it would be shown here, so the answer seems to be: no.
> 7 votes

# Answer
I've not bought any but nothing I've heard suggests they can, and looking at the designs I can't see how this would be possible.
> 6 votes

# Answer
None of them transform. You have to take them apart and rebuild them into each mode. They are essentially 2 models that use some of the same bricks between each mode.
> 4 votes

# Answer
I have built al of these sets, and I have to agree with everyone else on this one.

However! If you use a couple of the moving parts, or hack with some same-scale LEGO pieces, you can buid them to transform all by yourself.

The Optimus Prime set is actually potentially hackable enough to rebuild as a real transformer alone, but you won' t get it to look like a "normal" transformer, nor its namesake.
> 2 votes

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Tags: 3rd-party
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# Question
Title: Is there a place where you can buy single pieces of LEGO-compatible systems?
I've acquired a set of MegaBloks and was amazed at the slopes with studs on top. Unfortunately the set is $15 and there's only 6 pieces I need.

So I wanted to ask, are there any sites like Bricklink that sell MegaBloks? (Note: I'm talking about dozens of a single piece. No mixed bags, no used sets)

# Answer
Market places for MegaBlocks include:
> 2 votes

# Answer
Your question is answerable with a yes or no, so I'm going to have to say no.

The main reasons something like this doesn't really exist are likely as follows:

* As with some sets in LEGO, the prices for (say, Halo) are subjective and diasagreed upon.
* MegaBloks is fairly new, compared to LEGO, which is why you also don't see a pick-a-brick for KREO, Nanoblocks, etc.
* Additional, "loose" bricks aren't manfufacured specifically for this purpose.
* Perhaps most importantly, the range of set-specific pieces is far larger than a lot of other manufacturers, thus each piece's cost is based on which set it's from.

But will we see MB pick-a-brick in the future? Probably; stay tuned.
> 0 votes

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Tags: shopping, 3rd-party
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# Question
Title: How can a brick/color combination exist but not be part of a set?
In a recent question the 2x4 transparent brick in neon green came up as a rare part (see Where to find this green transparent brick?). It doesn't seem to be listed as part of a set (at least not on bricklink) but definitely gets traded sometimes (last sale on bricklink is for $75 in Oct14). How can a brick in a specific color not be part of a set but still be available? Why would LEGO make such a piece? Anyone who can provide some insights into this?

# Answer
> 3 votes
Some of these pieces are released as collectors items (Gifts for Lego employees) or sold as novelties at LEGOLAND parks or stores pick a brick areas, others are from official Lego events (grand openings of stores, new LEGOLANDs, etc.) they are often given as gifts to people attending the events. Some are test bricks that somehow made their way out of the factory to the Lego community.

They often have unique colors or images (there is a whole series of transparent/sparkle bricks that were made as tests for new colors and manufacturing techniques.)

The LEGOLAND parks and builders also have access to parts and color combinations not available to the general public for use in making new sets, if they are not used in a set I imagine some of these could also make their way to the larger community of Lego enthusiasts.

# Answer
> 1 votes
I fully agree with the previous answer, but would also like to note that there are a few pieces that can only be found in LEGO pick-a-brick as well.

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Tags: piece-information, colour
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title: System files deleted somehow

text:
# Question
Title: System files deleted somehow
I think my son accidentally deleted all the system sound/image files, etc. I have tried loading the firmware but that does NOT restore the files. Is there not a way to just upload the system sound and image files to the brick? They are so easy to delete, you'd think there would be a way to put them back....

# Answer
Sadly, my friend, this is less of a LEGO problem, and more of an issue with the kind of basic tech EV3 runs on. It can't afford to have a backup, it needs to be compact. You'll have to put them back on file by file.
> 1 votes

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Tags: ev3
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title: Dark metallic gray tube: Is it a LEGO?

text:
# Question
Title: Dark metallic gray tube: Is it a LEGO?
Unfortunately, I no longer own the piece in question. But here are the specs:

1. Dark metallic grey, like Super Battle Droids.
2. Somewhere in the vicinity of 6 inches long.
3. Flat ends: not a cut or broken pice of something else.
4. Fits perfectly in a hole for basic minifig-grabbable bars.
5. Not easily bent, but can kink slightly.

If this isn't a LEGO, say so, but bring some proof please.

# Answer
> 2 votes
Sounds like 'Hose, Rigid 3mm D. 16L / 12.8cm' in Pearl Dark Grey. Super Battle Droids are also in Metal Blue but none of the hoses exists in this color. Also note that the linked hose also exists in other sizes too and that the exact piece you have had might have been cut.

Note that colors mentioned refer to Bricklink's color names, LEGO company's official color names are different.

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Tags: part-identification
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# Question
Title: Looking for instructions for brick set #135149, silver robot head and black police vest?
I have part two and part three of the this set and I am pretty sure this set has to come from the "Lego Movie" series. The reason I say is because one of the bags has one or two of the secret police robots in it. Can anyone help identify this set? I can't find any info on any of those sets in that series.

# Answer
> 4 votes
You are looking at 2 bags from set 70808 - Super Cycle Chase. This is the only LEGO Movie set that has the robo SWAT cop head, the fence, the white 1x2x2 panel and the 1x4 plate with 2 studs in it.

There are 3 other sets (big enough to have a bag 2 and 3) that have this particular robot police officer head in it, namely:

But none of these have the additional pieces as shown in the picture.

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Tags: instructions, the-lego-movie
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# Question
Title: What is this 11x6 white and dark grey motorized LEGO piece with blue buttons and a transparent blue panel?
My brother bought a big tub of LEGO recently and found this piece inside. He doesn't know what it is and we can't find anything about it online so we were wondering what it is. He says it isn't in any of the instruction booklets he received with the LEGO so it doesn't seem to be a part of any of his sets. It appears to be a motor, with a white front, grey back, a display and blue buttons. When you turn it on it displays the word LEGO one letter at a time on the display. It also makes sound by bleeping and stuff when you turn it on and as it runs.

It has the LEGO logo in each of the holes and underneath so we assume it's an authentic LEGO piece, but it doesn't have any sort of identification number on it that we can see.

Thanks for the help.

# Answer
This part is called

Micro Scout with Dark Gray Base

the white version on your photo comes from

9748-1: Droid Developer Kit

(pictures via Bricklink)
> 6 votes

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Tags: motor, electronics, robotic
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# Question
Title: LEGO clone identification with letter B on studs
What LEGO clone is this?

It looks like LEGO, but I can't seem to find anything more.

Could you please help identifying this?

# Answer
> 1 votes
I couldn't find anything with Google in any reasonable amount of time, but here are some things it *isn't:*

* BanBao
* Best-Lock
* Cobi
* K'nex
* Kre-O
* Lite Brix
* Mega Bloks
* Tyco Super Blocks
* Sluban
* Wange
* NanoBlocks
* PlayMobil
* Star Diamond

Other than super obscure Chinese LEGO direct-steals, there aren't really any others.

But here is a legitimimate idea nowadays: They're printed. Face it, the top of each brick *definitely* has the trademark plastic lines of an untreated 3D -printer job. People are printing and/or selling bricks all the time these days!

And if you love them *that* much, you could have somebody make some for you!

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Tags: part-identification, clone-brands, 3rd-party
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title: LEGO Torsos cracking

text:
# Question
Title: LEGO Torsos cracking
I have just recently acquired the new crossbones' hazardous heist, and suprisingly, not even a week went by and my really sweet Black widow figure already has a small crack in her side. Will This damage the whole side? I'm really worried, does anyone else have this problem? How can I fix it?

# Answer
I would go ahead and contact LEGO customer service and tell them about this. They will want to know as they have high quality standards and this might indicate a defect bigger than just your copy. Also, they are more than likely to offer you a free replacement figure - keep that one safe and disassembled until the one you have is too damaged.
> 1 votes

# Answer
Depends on where the crack is. If it is near joints like the legs or arms, then probably you should find a way to seal it. Else other than design purposes it won't harm the figure
> 0 votes

# Answer
From experience the only problem from cracks in the side is that the arm is very loose and the legs don't have a good connection to said torso. Otherwise it is just an unfortunate look.
> 0 votes

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Tags: lego-store
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# Question
Title: How to tape something to the bottom of a brick
I'm installing lights in my buildings (I'm using Neopixel strips, which have a flat back), and I'm trying to tape the lights to the ceiling. Of course, bricks and plates aren't smooth on the bottom, so double sided tape isn't working out too well.

Can you recommend either:

* A plate or similar part with a smooth bottom (I'm familiar with the 2x2 round plate that has a rounded bottom, but I can't think of anything flat)
* An alternate method of affixing small parts to the bottom of bricks and plates

# Answer
Take a look at 11203 - Tile, Modified 2 x 2 Inverted. Works like your 2x2 round plate but is flat at the bottom.
> 1 votes

# Answer
> An alternate method of affixing small parts to the bottom of bricks and plates:

Check out sticky-tack! It has a ridiculous amount of brand names, but it's basically a safely removable, free-form version of duct-tape. It will stick to anything, and increases its own surface area by spreading all throughout something like, say, the little pins and circles on the bottoms of a brick or plate. Instead of being less effective in this scenario, it actually has more grip, and will stay on.

Another benefit is that it all comes out in one piece, so no tooth-pickery.

Sticky tack sticks to itself as well, so it's perfect for affixing electrical components, especially LEDs and other bits with pins. For a NeoPixel strip, it's still light enough that with a decent amount (which isn't much- you buy by the pound for like 3 bucks,) you can affix as many as you could possibly dream of and have plenty left over. The flat back is no problem, remember, it sticks to everything.

Alternatively: There is also a far more common piece than the 11203...

You know those 2x2 plate bottoms with a round bottom surface? However you intend to affix your strips to your piece, they should work fine, and the plus is how cheap they are.

And, since I've only seen a couple of those strips, (maybe they already have a sticky surface?) it's possible that sticky tack won't work. But even if the strips *do* have sticky backs, the tack will still hold them. Maybe even better than just regularly against a flat bottom. It's a good bet. For cheap.
> 0 votes

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Tags: piece-usage
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title: Strongest LEGO structure - (2) Floor

text:
# Question
Title: Strongest LEGO structure - (2) Floor
What is the strongest LEGO box structure?

I am going to build a LEGO computer case. Different from Mike Schropp and greenyouse, I am planing to build an upright case.

*(This is a general "strongest LEGO structure" question. Using the structures in building the computer case is just an example of applications.)*

To make it more challenging (and more perfect), the case will have handles (like this type) for carrying the whole thing around, and it will have "legs" (like this bar type) to lift the whole case up for ventilation.

*For better reference, here is the coordinate notation:*

There are 4 parts (for now I can think of) in the case which has to encounter different types of strength challenges:

1. The pillars (Red)
2. The floor (dark grey)
3. The joints (purple)
4. The handles (yellow)

For the white bricks, they do not require special strengths, do they?

FYI, here are the LEGO dimensions:

**Horizontal pitch**, or distance between knobs: **8mm**.

**Vertical pitch / Brick thickness**: **9.6mm**.

The horizontal tolerance: 0.1mm.

**Plate thickness**: **3.2mm**.

---

*Above is the common information across the 4 questions.*

*Below is the question for this specific part.*

---

(2) The floor (dark grey)

Someone has done some experiences against the effect of weight on LEGO bricks (results at slide 11). From his experiments, the Flemish structure is a clear winner.

Like the pillar problem, I wonder why not stack plates/bricks up along the X/Y axis, instead of the Z axis?

My suggestion is basically the structure of the pillar rotated clockwise along the Y axis, and extending it along the Y axis.

For those who have not read the pillar section yet, this is simply stacking up plates along the Y axis.

Same as the pillar, there is a risk of the plates separating due to the weight. So I make a "doughnut" to secure the plates.

Here is how they look like together.

I assume using longer plates will be better than short plates, because fewer connecting points, lower risk to separate, isn't it? However, in the presentation mentioned above, the result suggests that a mix of long and short plates has the most strength. Does this theory apply to my "Y axis structure"? And how long and how short combinations will be the best?

In addition, in my "Y axis structure", will using bricks instead of plates be stronger?

However, thing is more difficult here than the pillar. It is because the tension is **not** only pulled along the X axis. Instead, the weight is applied down the Z axis, and tension is all along the X and Y axis. So I assume this structure, when used as floor, will be a lot weaker than used in the pillar.

Please suggest any of your structure ideas which will be the strongest.

# Answer
> 2 votes
Just like in the other question, I would recommend a Technic frame with more depth than your original idea and some plating on top of it. This project nicely illustrates how to build stable Technic structures using beams in triangle configurations.

# Answer
> 1 votes
This question is amazing and well-thought-out, but it also made me laugh.

Building a LEGO floor? The problems with the structural integrity of any floor are simple, as follows:

1. The integrity of the walls above; how well they "grip" the floor.
2. The integrity, if applicable, of the walls *below*, how well they hold the floor *up*.
3. The integrity, or more specifically torque resistance, of the floor.

The structural engineer can now see why this brought out a chuckle.

For a LEGO build, the floor will be placed, inherently, on another floor. Thus, except in multi-story skyscraper builds, neither issue 2 nor issue 3 apply.

The real floor supports your LEGO floor with ease; otherwise it wouldn't be holding you very well.

The only thing to worry about is how good your connections to the upper pieces, (walls,) of the build are. Thus, neither your floor nor your ceiling, (You shouldn't put anything on top anyway, at least not something heavy, will be any trouble. However! Your connection to the sides of the case is very important. If the bottom falls out when you pick the unit up, it's no longer a good day.

*TL;DR*

*The floor itself, provided you don't use a single plate, or aren't holding up real actual cement bricks, will be perfectly fine, you should worry about keeping the walls connected to the base , i.e a dovetail.*

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Tags: building, design, plastics
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title: Need help identifying these 3 bags

text:
# Question
Title: Need help identifying these 3 bags
I got them as a gift but without the packaging. I only have three bags numbered 1, 2 and 3.

Can someone help me with the series number? Much appreciated.

# Answer
These bags are very likely the Cargo Truck (60020).
> 3 votes

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Tags: set-identification, city
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# Question
Title: How to parameter the ports in move tank block EV3?
How do I parameter the ports at Move Tank block (in My Block)?

# Answer
> 1 votes
Create a My Block that looks something like this:

Then you can select the ports like this:

The 23 means ports B+C (see below).

---

From the help file:

> ## Wired Input of Two Ports
>
> If you configure a Move Steering or Move Tank block for wired port input, you will need to specify two different port numbers: one for the left motor port, and one for the right motor port. This is done by using a two-digit number for the Port input. The first digit of the number (the 10’s digit) specifies the port number for the left motor, and the second digit (the 1’s digit) specifies the port number for the right motor.
>
> ```
> EV3 Motor Ports
> (Left, Right)     Value of Port input
> -------------------------------------
> B, C              23
> C, B              32
> A, B              12
> A, D              14
>
> ```
>
> See the table above for the individual motor port number values. The table below shows some examples of Port inputs to specify two ports.

---
Tags: ev3, programming
---


title: What do these bags make?

text:
# Question
Title: What do these bags make?
I am trying to organize my sons LEGO bricks and we cannot find a book or what these bags go to. Not even sure the bags go together?

Bag 5 has grey pieces and these long red things that look like you shoot them at something.

This bag has yellow wheels and lots of other grey, red and yellow and some black

Bag 2 with yellow and grey and black and little red and maybe two blue also a grey clear windshield piece

This bag has lots of grey light and dark and some red tan and black in it and a couple blue small ones

# Answer
Bags 4 and 5 are from set 75050-1: B-Wing based on the red Arrow 8M For Spring Shooter, 4211725: Plate 4X6 26 Degrees and 4233485: Brick 1X2 With Cross Hole

Bags 2 & 3 are from 4202-1: Mining Truck based on 4210720: Plate 6X14, 4210794: Plate 6X8, 4490139: Rim Wide W.Cross 30X20, 4188313: Coupling Plate 2X2 and 4515351: Plate 4X4 Round W. Snap in combination with the different red parts
> 6 votes

---
Tags: part-identification
---


title: What's a good base collection of tiles?

text:
# Question
Title: What's a good base collection of tiles?
I recently picked up a copy of the LEGO ideas book, and been inspired. As a novice builder, I've noticed that almost every model makes use of tiles to provide a finished look, which seems like a great idea.

Accordingly, I'm interested in buying some tiles in bulk for assorted building projects, but I'm overwhelmed by the options. Bricklink has many kinds of tile. What would be a good starting set of tile pieces to aim for, and roughly how many? And what's the difference between tiles with and without grooves? Is the groove on the bottom? Is one piece much more useful than the other? Argh! So many options! Can anyone recommend a sensible way to proceed?

# Answer
Looks like there are really two different questions here. Allow me to address the question regarding grooves on the tiles:

> What's the difference between tiles with and without grooves?

Basically, on tiles *without* grooves, the vertical edges run continuously straight from top to bottom. On tiles *with* grooves, there is a small lip at the bottom of the tile just large enough for a fingernail or a separator tool.

A visual comparison between the 1 x 2 tile without groove (red) and the 1 x 2 tile with groove (grey) shows the continuous vertical sides vs. the lip that forms the 'groove':

> Is the groove on the bottom?

Yes, it runs all the way around the bottom of the tile.

> Is one piece much more useful than the other?

The difference is mainly in the ease of removing the tiles once attached to another Lego element. As I mentioned above, the groove leaves enough space to prise the tile away from whatever other LEGO element it is attached to. In the case of the 2 x 2 Tile without groove that you reference in the question, according to bricklink, it was discontinued in 1978 after the 2 x 2 Tile with groove appeared in 1973, so I would guess that LEGO considered the 'with groove' to be a better design.
> 10 votes

# Answer
Whilst I can't answer specifics on types and quantities, look out for sets that include a reasonable umber of tiled pieces. The modular buildings all include a fair number and range, as do the Minecraft series of kits. Our local Lego store (Watford, UK) had a whole cup of 1x1 tiles all in a dark colour that someone had put to one side, but they weren't 'on the wall' when I looked.
> 0 votes

# Answer
What to do for tiles? Have a collector rifle through their collection for hours and see how many of each piece they have! (Did that for you.) Here's the base you wanted:

* 10 1x1 wih studs, 20 without
* 200 studs (some say they're plates)
* 20 2x2, both kinds each, 30 circular, 10 circular without studs
* 16 1x2, 8 without studs, 8 grilles
* 4 3x1, both kinds each
* 8 3x2, studless don't exist
* 40 4x2, 4 studless
* 8 6x2
* 4 8x2
* 4 10x2
* 4 4x4, 6 circular, 2 open circular
* 6 6x4
* 4 6x6
* 4 10x6
* 1 baseplate
> 0 votes

---
Tags: piece-information
---


# Question
Title: LEGO Friends drinking bottle (850817) containing BPA?
LEGO has recently released Friends drinking bottle 850817, but there's no mention anywhere (not on the product itself, not on the product's web page) as to whether the product contains BPA (Bisphenol), a dangerous chemical (especially for children) commonly used in bottles.

Question: Does this product contain BPA?

---

**Edit:** This is not a duplicate question because it concerns a drinking bottle released in 2016, not vintage LEGO bricks. In addition, please note that the bottom of product 850817 has a recycling symbol with the number 7:

> **How Can You Tell if a Container Has BPA?**
> A resin code of 7 appearing on plastic containers indicates that the container may be made of a BPA-containing plastic. (U.S. Food and Drug Administration)

# Answer
> 1 votes
Remember the BPA scare? It's all but a crime to release a product that even *thinks* about having BPA. But I did the search anyway, and no, there is not any in this or any other LEGO product I can find to date. LEGO is pretty good about nontoxic products, drinking use intended or no. I mean, they're made for kids. Good question though.

---
Tags: friends, accessories
---


# Question
Title: What is the name of this 2x2 curved piece with a lip?
What is this piece called, and what are its degrees?

# Answer
This is part number 30602. Brickset refers to it as "Front 2x2 Sport" and on Bricklink it is "Slope, Curved 2 x 2 Lip, No Studs".

The top is curved, so it doesn't have a clean angle like some slopes do and it's name doesn't include an angle measures in degrees.
> 3 votes

---
Tags: part-identification
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title: What is this 1x2 hinge brick?

text:
# Question
Title: What is this 1x2 hinge brick?
What are the two pieces that make up this hinge and brick?

# Answer
That's a 1x2 hinge brick. Here's a better image of what you're looking at:

This is part 3937 and 3938. Here are the two parts viewed separately:
> 5 votes

---
Tags: part-identification
---


title: Most common Lego piece?

text:
# Question
Title: Most common Lego piece?
I know there are many candidates for a rarest Lego piece, but:

**Is any specific brick truly the most common? Which? Which color?**

I've wondered for a long time about this.

Make sure to include details, as in proof, and if a line is blurry, defend both points.

# Answer
> 8 votes
If you look at the quantity of parts in all sets, the most common is the 1x2 brick ignoring color. The most common part and color combo is the Techhnic pin with friction in black.

These stats were pulled from Rebrickable's database \- they previously had a "Stats" page, but this has since been replaced with their API.

---
Tags: history
---


# Question
Title: Chicago Blackhawks logo Lego building instructions
Can anyone make some building instructions for the Chicago Blackhawks logo that's made out of LEGO bricks? I'm trying to find so I can build it for my sick brother.

# Answer
This is the closest you're likely to get, I made it myself. Basically, LEGO art is a form of pixel art. The 2x2 brick is the best brick for this purpose, but often you can use blocks of other length to make the build faster, and more sound. All I did here was take a basic Blackhawks logo, apply a pixelation filter, and then hand-integrate all the pixels into the basic LEGO pallet. I also hand-placed studs for reference, and used a non-LEGO color for the background, and a shadow, to remove confusion. Then I squished all the pixels down to LEGO proportions.

You will be using a lot of yellow, 2 light grey, 4 dark grey, a good bit of black, some green, some orange, and a little bit of white and blue.
> 1 votes

---
Tags: design
---


# Question
Title: What's this weird blue 8-long thin hinge piece?
I've spent several hours on BrickLink now trying to identify this mystery piece. It doesn't have a part number on it, only the Lego logo. It looks kind of like a hinge or something that might snap into a doorway, but I haven't found anything similar. Can you help me?

# Answer
This is part 4218 Garage Roller Door Section without Handle:

As you might imagine from the name, these can be connected and used for garage doors as seen in Century Skyway, for example:
> 10 votes

---
Tags: part-identification
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title: What is this technic axle?

text:
# Question
Title: What is this technic axle?
In this video, Kooberz uses this piece:

You can see it in action in this video at 15:06. What is the piece?

# Answer
> 2 votes
This is a regular 3 module length axle (4519):

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Tags: technic, part-identification
---


# Question
Title: What piece is designed to hold the "drawer" piece?
Cruising the good old PAB, I come across a piece called simply, the "drawer". From the image, I can conclude that this piece is meant to act like a real drawer, by pulling out of something.

Question: What is that something? What is designed to hold the drawer?

# Answer
> 4 votes
The part you are looking for is 4532a - Container, Cupboard 2 x 3 x 2 - Solid Studs. There is also a 4532 version with hollow studs.

---
Tags: piece-usage
---


title: What is this technic pin?

text:
# Question
Title: What is this technic pin?
In Kooberz' video, he uses a techinc pin that looks like
What is it called?

# Answer
> 3 votes
BrickLink says that it's called the *"Pin with Friction Ridges Lengthwise WITH Center Slots."*

However it may also be the *"Pin with Friction Ridges Lengthwise WITHOUT Center Slots."*

---
Tags: technic, part-identification
---


title: What is this BIONICLE limb piece?

text:
# Question
Title: What is this BIONICLE limb piece?
In Kooberz's video, he uses this piece. What is it called?

# Answer
Bricklink indicates that this is the *"Bionicle Toa Nuva Leg Section."*
> 3 votes

---
Tags: part-identification, bionicle
---


# Question
Title: Is it possible to access the RGB values of the EV3 Light Sensor?
I'm following a line with the LEGO EV3 Color Sensor in Reflected-light mode, I need to stop the robot when it detects a green tile in the ground, but I didn't succeeded in differentiating Green and Black, can I access the RGB values of the sensor, or in some way differentiate those colors?

# Answer
> 2 votes
Green does tend to be tricky on the LEGO EV3 Color sensor. Example

Here are some suggestions:

* Build a shroud to eliminate ambient light. I have seen people use electrical tape for this or build something from LEGO parts.
* Using the raw RGB values, convert to HSV (there is a link in Example 1 for this).
* Use the algorithm for the NXT color sensor from the EV3 source code. It will probably have to be adjusted a bit for differences in the sensors.

# Answer
> 0 votes
Yes try this. Color RGB This is the Color RGB sensor block. Installation instruction can refer from here

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


# Question
Title: What are these Technic sets with figures?
So I'm trying to identify these two LEGO sets that are rather old. I have long since lost the instructions and I can't seem to find the specific parts on BrickLink. Here are the photos of the complete builds: Album

I'm not sure if the two belong in the same set (doubt it). But they go together since the teal ship is supposed to fling its plungers to the purple guy's target which activates a spring and launches him out of his ship (and consequently turns off the motor). The purple guy moves around on top of the rubber wheel, which has unfortunately broke. The purple ship takes a 9V battery which powers the motor. I've included a closeup and as you can see the pieces connecting the electronic parts has metal contacts.

# Answer
These builds are both from the same set. Super Challenge (3038):
> 5 votes

# Answer
This is set 3038/8266 Super Slayer/Super Challenge, based on the occurrence of the Technic Figure in Turquoise.
> 2 votes

---
Tags: technic, set-identification
---


# Question
Title: Is it possible to use Bluetooth to connect two EV3 bricks using RobotC?
For example to send a numeric value from one to the other?

# Answer
> 2 votes
According to the online documentation, Bluetooth commands are supported for NXT but not for EV3.

On the other hand RobotC is supporting Bluetooth upload/debugging. This means that it is accessible. My first instinct would be to look at how RobotC did it (if the code is available). My second instinct would be to find if somebody already hacked the EV3 brick using C code.

# Answer
> 0 votes
No, Robotc does not yet support Bluetooth for the EV3 - I even tried doing it with the labview software and it gave me an error message when I ran it on the EV3 brick

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Tags: ev3, bluetooth, robotc
---


title: Reference LEGO Technic 42043

text:
# Question
Title: Reference LEGO Technic 42043
When installing the tubing starting on page 273 of the instruction booklet, the suggested length seems to be too short for the installation. Is it permissible to cut the tubing provided to fit the situation, or am I missing something in previous construction? If not able to cut the tubing, it becomes very congested connecting to the appropriate valve.

Instructions: http://lego.brickinstructions.com/m/lego\_instructions/set/42043/Mercedes-Benz\_Arocs\_3245

# Answer
> 5 votes
The provided tubes all have the correct length. If you start cutting tubes than you run into problems later on.

I have build this set multiple times an never run into problems. Make sure all tubes are routed correctly and by the shortest distance sometimes its needed to route a tube underneath another.

When you start building, what helps is sorting the different tubes by length and check if you have them all.

---
Tags: technic
---


# Question
Title: How is the LEGO plastic different from Megablok plastic?
It's obvious that LEGO has better quality control, but what about the plastic they use? Megabloks look *cheap* and the parts seem to vary in color in a side by side comparison next to LEGO brand elements. Why?

# Answer
> 6 votes
The thing with ABS is a bit more than that simple. The general rule is that if you want to have different/better plastic you need to play with small amounts of co-polymers. 99-point-something of your plastic is the main co-polymer, but the 0-point-nothing decides about fine-tuning of properties. A bit more than 10 years ago a friend of mine was working for Bayer (the one from aspirin). He gave me at the time two examples of their R&D. One was extreme shortening of hardening time for polycarbonate of CDs. In some years of development it was shortened from ~1min to some seconds. As the 2nd example - he told me a bit about the LEGO plastic. At the time they had a project for LEGO and its aim was to make plastic for molds better. They have machine that was interlocking bricks for several thousands times measuring all the time the force needed to connect and disconnect two parts. They made them self new parts (some of them were never on the market) and were trying to find additives that make LEGO bricks better (long time durability).

So to make whole this story short: I believe that in 99.9% both firms use the same material (*i.e.* ABS) however I also believe that LEGO plastic is qualitatively better. I will not argue that it's so much better that the price of any LEGO-set is reasonable. IMHO they are horribly over-priced but at the same time I'm still buying them for my kids. I hope they will last for my grandkids. :-)

# Answer
> 3 votes
Both Lego and MEGA Brands use injection-molded ABS (acrylonitrile butadiene styrene) plastic to manufacture their elements. The most obvious difference between the two manufacturing processes is that Lego elements tend to have thicker walls than Mega Blok elements. That accounts for the cheaper "feel" and less clutch power. Obviously MEGA does this to save money, although interestingly, there have recently been complaints that Lego has started to reduce their wall thickness for the same reason. (See, for example, this article on a recent Monster Fighters set: http://www.brickset.com/news/article/?ID=3504)

Another difference between the two brands is that Lego elements tend to be shinier than their Mega Blok counterparts. Based on my personal contacts with individuals who work in plastics, this is likely a result of using re-melted ABS instead of "fresh" pellets. If I had to guess, I'd say that Lego probably discards or recycles in another fashion the leftover plastic from their injection molding machines, while MEGA sends that plastic back through the process. Another possibility is that MEGA uses a less expensive plastics supplier with lower quality ABS.

Based on the first comment below, I agree that there is probably something else at play in the shininess of Lego elements relative to their off-brand counterparts. I found an interesting article (http://www.ptonline.com/articles/eliminate-surface-defects-on-molded-parts) that discusses the difficulty of achieving a quality finish on the surface of injection-molded plastic that may also explain some of the apparent differences between the MegaBloks and the Lego elements. Regardless, the wall thickness as discussed above is still the main noticeable difference between the two brands, and it is definitely a result of cost savings on the part of MEGA Brands.

# Answer
> 3 votes
"Both Lego and MEGA Brands use injection-molded ABS (acrylonitrile butadiene styrene) plastic to manufacture their elements." -by oddTodd Jun 15 '13

TL;DR: Mega Bloks are NOT ABS.

Based on oddTodd's statement alone, I went to the local resale shop and bought a few Mega Bloks for a few cents. My intention was to use the Mega Bloks as a source of colored ABS plastic that I could melt into a slurry in acetone.

I used a tapered drill bit to cut the block into shavings, placed the shavings into a glass jar, and covered them in acetone. I have done this process numerous times with known ABS components to create an ABS slurry.

The Mega Blocks didn't feel like ABS. They were soft, turned white when bent or stretched, and are absolutely impervious to acetone. Everything about this experiment reminded me of dealing with polyethylene or polypropylene.

---
Tags: piece-information, 3rd-party
---


# Question
Title: Is there a free EV3 simulator (virtual machine) for the Mac OS?
I recently saw this question on a virtual EV3 machine. From the video, I felt that this software will be great. However, I don't have the budget needed to buy a licence. Is there any alternative to this system?

# Answer
> 2 votes
You could try TRIKstudio: https://trikset.com/en/products/trik-studio

This allows you to program a robot based on the LEGO EV3 setup, however while the application itself has English, French and Russian translations, most of the online help is only in Russian.

# Answer
> 1 votes
If you are looking for free software, you can use the now abandoned Microsoft Robotics Studio. It has a virtual robot simulator. The project was shut down around the same time the EV3 was released, so I doubt that there is a virtual EV3. There is a virtual NXT though. And it is possible to create your own virtual robot models if you are willing to put a massive amount of time into it.

Also, this is Windows, software, so you will need Parallels or a VM to run on Mac.

# Answer
> 0 votes
Is this what you're looking for? Actually, this might be closer. NOTE: The latter is only compatible with iphone/ipad, but it might be closer...Other than that, I'm not sure.

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


# Question
Title: Identifying two BIONICLE parts, white and dark grey curved shell
What are these two BIONICLE pieces?

# Answer
These are Bionicle parts, specifically the back spine of the 8588-1 Rahkshi Kurahk.

The individual parts are:
> 2 votes

# Answer
Adding to zovits' answer, you also appear to have a Part 44136 attached to the Part 44139.
> 2 votes

---
Tags: part-identification, bionicle
---


title: Where are these BIONICLE sets?

text:
# Question
Title: Where are these BIONICLE sets?
I'm from Norway and I wonder why BIONICLE sets creature of jungle and stone are nowhere to be found around here.

# Answer
> 1 votes
I'm not sure why you say "are nowhere to be found around here" - perhaps you mean Brick & Mortar stores? Both these BIONICLE sets are available from the Norwegian shop.lego.com site:

---
Tags: shopping, bionicle
---


title: Mid-sized black plate options

text:
# Question
Title: Mid-sized black plate options
I'm looking for a mid-sized (16x16, 20x20 ish) black plate for mounting on a wall. It can be a regular plate or baseplate since what I am mounting it on is not Lego and it doesn't need to fit into studs underneath.

So far I have only found this piece but no-one seems to sell it in black

http://alpha.bricklink.com/pages/clone/catalogitem.page?P=91405

Are there other pieces I should consider?

# Answer
You can piece together a 16x16 black plate in two layers, by making a base layer consisting of 3867 - Baseplate 16 x 16 (not available in black, but Dark Bluish Gray is a good option and given the minimal thickness it won't show)

and then putting 4 of 41539 - Plate 8 x 8 in Black on top side-by-side.
> 3 votes

---
Tags: piece-information
---


# Question
Title: Lego NXT Exploitation or Vulnerabilities?
I originally posted this question on the Reverse Engineering site, but there were no answers. They told me to also post this question here. OK, my friends and I have Lego NXT sumo bot competitions for fun. Basically, you build a robot that waits five seconds and competes against a robot to stay on a board. We normally focus on the mechanical side to win against other robots (find them and push them off the board), but I had the idea to try a software attack. My idea was to:

1. Find some sort of Bluetooth vulnerability that I could exploit from another NXT (I write my programs in NXC).
2. Upload a malicious program that makes the robot drive backwards forever.
3. Somehow execute the program (and win)!

I have tried testing the NXT Bluetooth for vulnerabilities (I have knowledge of Windows/Linux exploitation and debugging) and I can't find anything. The main problem is that the NXT firmware handles Bluetooth connections, in other words you connect the devices with a pass code **before** running the program that requires Bluetooth. So, my questions are:

* Is this even slightly possible or is it just a waste of time?
* If there was a NXT Bluetooth vulnerability, could I even send it from another NXT that's not connected?
* Was this the right place to post this question?
* Would NXT debugging even be possible?

**Update** First, thanks for all of the ideas and answers. Secondly, several of the answers note about the legality of what I am trying to do. Yes, it is legal where I live. Third, I talked with main guy and judge of the competition and he said that he would love to see a software attack like this.

**Where I'm at now** I have Kali Linux and the mac address has been found. I also found a paper here on the control protocols. The main dilemma I am still facing is the fact that a Bluetooth passcode has to be entered **on** the device I intend to connect to. Any updates will be posted here!

# Answer
> 3 votes
> Is this even slightly possible or a waste of time?

It might be *possible* but requires effort and probably a fair amount of research and hacking on your part. I'm not saying I know for sure if an exploit exists, either in the communications protocol or the BT firmware, but exploits are always possible. And it's not like LEGO is incentivized to look for obscure security issues in this stuff -- it just isn't that important.

Exploits come in different flavours, as do attacks. One place to start looking is the vendors that LEGO sourced for the various pieces of the NXT platform, and not just Bluetooth. We are looking for manufacturers that have released security notices for their hardware and drivers in the hopes that an exploit is still in the wild in an unpatched device used on NXT.

Another trick is to decide what sort of attack payloads are available. For example, even if you can't get debug access to the device, maybe you could keep the device so busy with bogus or specially crafted connection attempts that you gain some advantage. A denial-of-service attack is often just as effective as a direct hack.

You want to start looking at all the I/O that NXT uses, and then see how you can exploit it for direct access or some sort of leverage that gives you an advantage of some other sort.

And often exploits are leveraged in concert to get the access the hacker wants. So, you want to collect as much information as possible, and then start hacking your Kobayashi Maru solution.

---

Well, I recently ran across this answer, which shows that the LEGO Group sometimes patches security holes. The best part about knowing about patches is knowing some version has a security hole.

# Answer
> 1 votes
I think that most sumo bot competitions do not allow interchange of information between bricks. And you have to connect via Bluetooth with your opponent's bot, which requires your opponent's permission.

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Tags: mindstorms, nxt, programming
---


title: Use Bluetooth to access NXT display

text:
# Question
Title: Use Bluetooth to access NXT display
I'm planning to use NXT to troll my friends, and I want to show something on the screen that I send to it via Bluetooth. To clarify, I want to type it on a computer in another room. Is there a way to do this all in the NXT software? (no coding) Thanks - Sam.

# Answer
You can remotely start and stop programs from the NXT software. So create a simple program that just has a few display blocks and an empty loop at the end to keep the program from stopping then run the program.
> 1 votes

# Answer
I just had an idea. Have the output of the bluetooth message receiver block run into the input of the display block. Then, I have some other device sending messages that I type in.
> 0 votes

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Tags: mindstorms, nxt, software, bluetooth
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# Question
Title: How do I get Batman out of DC Comics Super Heroes Character Encyclopaedia without damaging the book?
I know less than nothing about LEGO, I bought the book because it was on offer and looked cool. How do I get Batman out of the book without damaging the book? I can't seem to find any instructions

# Answer
> 3 votes
You simply open the front cover and you can take out the minifigs from the back. It won't damage the book at all.

# Answer
> 2 votes
There is a plastic casing on the back of the cover held together with a piece of tape. Cut/break the tape, and then use a fingernail or other thin option to pull apart the two plastic pieces from each other. This opens a small door of sorts, from which you can take out the figure.

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Tags: minifigures
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title: How can I fix my chewed up LEGO head?

text:
# Question
Title: How can I fix my chewed up LEGO head?
When I was about 8 I used to bite down on loose LEGO heads to "fix" them. Of course after the heads "treatment" they would have chew marks around the neck.

Is there any way to make these marks less noticeable? One of my old favorite LEGO heads have these marks. I can't buy a replacement because the head isn't made anymore.

I could buy one on ebay... If I had my own credit card/paypal/etc. and my mom would gain the knowledge that ebay isn't evil just because it's online. What should I do?

The only idea I have is to put some nail varnish over the chew marks.

Here's a picture of the head. I don't know if it helps much since you can't really see the chew marks.

# Answer
> 7 votes
Your best bet would still be BrickLink. Many sellers there accept cash, checks or money orders, so you don't necessarily need paypal or a credit card. However if you would like to work on fixing the bite-marks on the head you pictured above, there are several things you can do:

1. If the bite-marks are not too deep, you can sand down the area with very fine sand-paper to make it more even. The sand-paper must be very fine, otherwise the surface would end up getting even, but rough. I have found wet and dry sand-papers the best as it can provide a very smooth finish.
2. You could try your nail-varnish idea, but please note that nail-varnish actually melts the plastic, so use only very little. You might also try other type of clear varnish that is fairly thick. Make sure you try it first on a piece you don't care for to see how it reacts with the plastic.
3. Because plastic is fairly soft, I found that sometimes you can smooth out bite-marks just by the back of a kitchen knife. :)

# Answer
> 0 votes
Depends on how deep the bite-marks are. For a thin mark, TheBrickBlogger's answer with the sandpaper of kitchen knife should do the trick. For something deeper, heat up a tool of some sort, something with a non-conductive handle, and melt it a little into itself.

# Answer
> -1 votes
You could try filing it with a nailfile or sandpaper.

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Tags: minifigures, repair
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# Question
Title: Purchase of large blocks in South Africa
I have thousand's of small-single, two and four blocks but sometimes need to build larger structures and thus, would like to know were in South Africa I can purchase these larger blocks without all the smaller blocks

# Answer
There are some BrickLink stores that operate in South Africa. You should be able to get from them whatever you need. Here is the list of stores: http://www.bricklink.com/browseStores.asp?countryID=ZA
> 1 votes

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Tags: building, sets, compatibility, replacement-parts
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# Question
Title: Help finding Star Wars set, 8x8 grey cone with white end
Bought a bulk lot of LEGO with no instructions. I have one piece I can't locate the set for - any help would be great.

# Answer
> 4 votes
Based on the one picture that did come through, you have set 9490 - Droid Escape from 2012.

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Tags: set-identification, star-wars
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title: EV3 brick freeze during run big program

text:
# Question
Title: EV3 brick freeze during run big program
EV3 brick sometimes freezes while executing huge programs and do not react on buttons and bluetooth (connect, start/stop program). Only way to continue work is hard reset. We discovered that freeze depends on medium motor blocking. Is there any way to fix this?

Program: http://puu.sh/iQuFg/678d3add5f.ev3

# Answer
My kids have this exact same problem when a program reaches a certain size. Parts of the program that previously worked just fine begin to systematically cause the brick to lock up. We have found, as ridiculous as this sounds, the simple act of adding a variable read immediately before the motor block which seems to cause the brick to lock up will fix the problem.
> 2 votes

# Answer
Did you set the medium motor block at On For Degrees mode? If you did, the motor would attempt to spin and run until it reaches the degrees set in the block. You could replace the block with wait for X seconds.
> 1 votes

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Tags: ev3, ev3-g
---


# Question
Title: Access WeDo on OS X from a real programming language
I'm trying to talk to the WeDo USB interface from Python or really any real programming language.

I tried the clever WeDoMore library, but can't get it to bind the WeDo. I think this is because the WeDo is a HID device and the built in Mac OS HID driver binds to it before libusb, a dependency of WeDoMore, get's a chance to. But, my understanding is a little shaky.

The developers of WeDoMore are quite helpful, but don't use Macs themselves.

Any hints that would get me talking to the WeDo would be greatly appreciated. Scratch works, but I'm looking for a more standard programming environment.

# Answer
> 1 votes
Here's what I found researching your issue:

1. It seems that the issue with Mac OS X's kernel claiming HID USB devices before libusb does is a known issue since OSX 10.5 (see here).
2. Libusb has no functionality to alter this behavior, so it would be up to the WeDoMore developers to use an alternative way to utilize USB on the Mac if they want to build in this compatability. From the post in my bullet #1 it sounds like utilizing HIDAPI is a good way to do this.
3. There might be a way to blacklist the WeDo USB interface under Mac OS X, but since I am not a Mac owner nor programmer, I cannot help you with the feasibility of this option. Details here. It seems to require the development of a 'KEXT' which requires an Apple Developer license to do.

# Answer
> 3 votes
It *is* possible to drive the WeDo from Python on a Mac, without a kext. I've only tested motors since I don't (yet) have the other sensors. You need to access the USB HID device directly. There are a couple of prerequisites to install:

You'll likely want XCode and friends installed to be on the safe side.

There are a number of forks of cython-hidapi available so your mileage may vary depending on which version you use. I don't remember installation being problematic.

Once those are installed and your WeDo is plugged in you can do something, at a minimum, like:

```
import hid
import time

# vendor id, product id:
dev = hid.device(1684, 3)

# turn both motors on
# HID format is reportID, message type, data1, data2, ...
dev.write([0x0, 0x40, 127, 127, 0x0, 0x0, 0x0, 0x0, 0x0])

time.sleep(1)

# turn them both off
dev.write([0x0, 0x40, 0, 0, 0x0, 0x0, 0x0, 0x0, 0x0])

```

The changes to get WeDoMore to use hidapi instead of generic usb on a Mac don't look to be too onerous. If I manage to get something committed I'll update my answer with a link.

\[Edit: I've committed a fork of WeDoMore that adds support for motors on the Mac here. Again, I'll update if the pull request gets accepted\]

Small side-note: The WeDo can also drive 9v motors with the correct converter cable. I *think* it's possible to read the RCX sensors as well, but mild soldering may be required (see, e.g. here for a proof of concept). But if the WeDo can be fooled into reading the devices then Python can be used with those other sensors.

# Answer
> 3 votes
I just created a Node.js library that supports reading and writing to the Lego WeDo kit: https://www.npmjs.com/package/wedo-support

## Install

`> npm install --save wedo-support`

## Use

```
const WeDo = require('wedo-support');
const wd = new WeDo.WeDo();

// Activating the first motor full forward:
wd.motorA = 100;

// Activating the second motor half speed/force backward:
wd.motorB = -50;

// Current value of the tilt sensor:
const theTilt = wd.tilt;

// Current distance value in meters of the distance sensor:
const theDistance = wd.distance;

```

This library uses the https://www.npmjs.com/package/node-hid library for USB support, which works on Mac OS X.

I'm on El Capitan and it works well. I haven't tested on Windows or Linux, so if someone wants to try it out and provide feedback / submit a pull request, I'd be happy to accept them.

I also determined that the motorA and motorB work with lights as well.

Happy WeDo-ing!

---
Tags: programming, wedo
---


# Question
Title: Can you identify these parts? Sliding brick and plate with a groove
Please help me identify these LEGO parts - I'm trying to build them.

# Answer
> 8 votes
The plate is probably a Plate 1X8 With Rail or maybe Plate 1X2 With Slide

The Brick is a Sliding Piece 1X4

---
Tags: part-identification
---


# Question
Title: Curved little bar piece seems incredibly useful... what is it?
On this link, there is a special recurring curved piece throughout the photos. It is light grey, can be held by a figure on both sides but not the middle, and looks a little like a paint-roller handle.

What is it? I want, like, 30!

# Answer
This piece is 12885 Minifig, Utensil Paint Roller Brush Handle.
> 6 votes

---
Tags: part-identification
---


# Question
Title: What are some "Illegal" LEGO combinations?
On Brothers Brick, there is an AFOL term for bad LEGO combos: **Illegal**. These combinations are "unconventional" and put stress on the bricks. Essentially, they are nonconformist, risky maneuvers, typically compromising the integrity of any parts in it.

For example -- from the site -- wedging a flat plate between studs on a brick. I have used this term before, and can testify to dangerous combinations. So I'm posing this as another challenge for the community, like my hard to separate combos.

**What are some Illegal combinations * you\* have found?** Largest number of unique combos wins! (please don't *try* to kill anything for this.)

# Answer
> 19 votes
I do not think it is up to us to determine what is considered an Illegal Technique - TLG (The LEGO Group) determines this for their commercial products. It depends on how much of a purist you are whether you apply these constraints in your own builds. That said, LEGO Designer Jamie Berard has made a presentation in the past that highlights most Illegal Techniques.

Some examples:

* Studs-on-side bricks cannot have their side stud in the hole of a technic brick
* Bricks mounted SNOT style onto Ehrling/Headlight bricks cannot sit directly above a normal stud (the minimal height of the LEGO embossing makes that combination illegal)
* Technic pins have to be fully inserted into technic holes, otherwise they stay in compressed state which causes stress on the element.
* Plates cannot be inserted with their studs into technic bricks, unless it is a 1x1 plate (so only 1 hole is used) and there is no brick attached to the technic brick directly above the inserted plate.
* As mentioned by you already, you cannot insert plates between studs (this used to be a valid technique 20+ years ago, but is no longer considered "legal" by LEGO).

# Answer
> 11 votes
One illegal technique I've seen was two elements stuck together using a sticker to bind them. The builder claimed that the solution was "purist" because it was a lego sticker from a set.

---
Tags: challenge
---


# Question
Title: Which 3307 Arch 1 x 6 x 2 is correct for 10225 R2D2 Set? "Thick Top with Reinforced Underside" or "Thin Top without Reinforced Underside"
BrickLink shows that the 10225 R2 D2 set contains 3307 Arch 1 x 6 x 2 "Thick Top With Reinforced Underside", but I purchased that set and mine contains the newer "12939" variation which is described as "Thin Top without Reinforced Underside". Does anyone know which is the correct ORIGINAL arch variation contained in this set? And when did the change take place?

# Answer
I got my R2D2 at launch in 2012 for the May the 4th celebrations through the Dutch Lego@home web shop. This set contains the old 3307 part.
> 1 votes

# Answer
I cannot give you the definite answer, but LEGO changed the design of the "Brick, Arch 1 x 6 x 2" two times over the last 6 years. The original version is 3307 which was in production/circulation until 2014. It then produced 12939 which entered production/circulation in 2010 and is still out there in new sets, however, in 2014 LEGO started producing yet another design numbered 15254.

Since 10225 R2D2 was produced for about 2.5 years from 2012 to 2014, it fell right smack in the middle of the change-over between these 3 molds. So per set it really depended on what mold had been printed and was sitting in the supply for the given production facility - some sets will have gotten 3307, other sets 12939 and even some late sets will have gotten 15254. For LEGO there is no difference in these parts and they will have been substituted.

Bricklink indeed mentions 3307, but has 12939 listed as alternate, so it recognizes both came in this set. Brickset has both 12929 and 15254 as parts for this set, and Rebrickable has 3307. Finally, BrickOwl is missing this piece from its inventory altogether.
> 2 votes

---
Tags: piece-information
---


title: Where are the 2 by 2 turntables in LDD?

text:
# Question
Title: Where are the 2 by 2 turntables in LDD?
I just updated to LDD to 4.3.9 today and I can't find the 2 by 2 turntable pieces. What section are they under now?

# Answer
> 3 votes
You'll find them in the hinge parts category (next to minifig one) under the name "Turn Plate 2x2", number 3679 / 3680. Brickset uses LEGO names for parts, this can help finding them in LDD

# Answer
> 2 votes
I agree with **SMS von der Tann**... I'd upgrade LDD to 4.3.9 and the turn plates 2x2 ARE NOT in any category anymore (I seek it everywhere more than twice). My solution was to save a 2x2 turn plate, from another LDD model I made before upgrading, to the templates and then re-use it when I need.

Regards

# Answer
> 2 votes
If you temporary change your theme to the extended LDD, the turntables are still in the hinge section, this way you can paste them into your build and color them, after that you can change back to the normal theme of LDD

---
Tags: ldd
---


# Question
Title: I have several sets of unidentified Lego bags with no part number. How can I figure out what to build?
I have a photo but it is too large to post. These were donated to me.

In fact, I have a huge tub of random Legos that were donated to me and I have no idea how to organize the parts. Most were not in Lego bags. The bags say @The Lego Group 2007 and each one has a single digit on it ( 2,3, 6, 9). There are no directions.

# Answer
> 4 votes
You must classify parts first and find out which parts you have. You can always use Rebrickable website which is a great system that gives you the sets you can build with your parts. Most difficult part of the answer is of course classifying the parts and upload them to your Rebrickable account but once you done you can find out what you have and google the instructions.

# Answer
> 1 votes
You could try to find some details via http://brickset.com/sets/year-2007, be warned you will get a long list. If you have a bag numbered 9, then it must have been a big box. So try to sort by number of pieces in descending order.

---
Tags: set-identification
---


# Question
Title: Where can I find a good tutorial on programming with Lejos?
I want to get started with LeJOS and use Java to check to see if an EV3 touch sensor is pressed, but I can't find any decent tutorials. Are there any good resources for this?

# Answer
> 3 votes
The makers of LeJOS maintain a blog on WordPress: https://lejosnews.wordpress.com/ where they also give tips and write howto's. I think that is the best place to get started, apart perhaps from the LeJOS.org wiki pages which are located here: https://sourceforge.net/p/lejos/wiki/Home/.

Those wiki pages tend to have some inconsistencies between versions (some of it is not yet updated to the latest version of LeJOS EV3) but when I got started with LeJOS 2 years ago I found it quite easy to get going using those pages.

Of course, all of these pages assume you understand how to write programs in Java - otherwise you'd need to look for a Java tutorial, like the ones published by Oracle at https://docs.oracle.com/javase/tutorial/.

---
Tags: ev3, lejos
---


# Question
Title: Minifigure arms and legs do not have stamps
I have loads of minifigures from the 1980's and have just found out that none of the arms or individual legs are stamped with the LEGO logo.However, torsos, heads, and hips are all stamped. Does this mean they are not genuine parts?

# Answer
> 2 votes
### Nope!

Torsos and leg-pieces are special. They are some of the few pieces of their size that are not actually two separate parts of different IDs. Torsos actually include their two arms, which is why they come assembled, with the arms and hands already attached, and only the torso is stamped. Legs are actually a three-piece combo of left, right, and waist. A mini-figure is made of (typically) a hat/hair piece, a head, a torso-combo, and a leg-combo, all of which have only one stamp apiece. So fortunately for you...

**All of your pieces are legitimate.**

---
Tags: minifigures
---


title: LEGO controller 8879

text:
# Question
Title: LEGO controller 8879
How does the LEGO Technic 8879 controller work? When you make it go forwards/backwards and let go does it stay at that speed like the more recent helicopters or does it go back around? And how does it go forwards and backwards, is it like the 8885 controller where you have to have a motor for each of the front wheels to turn?

# Answer
It is not spring loaded, meaning if you set a dial to a specific value it will stay there. There are two channels that can be controlled with the two dials, and either can be set in one direction ("forward") or the other ("reverse"). I put these terms in quotes because their exact function depends on your model, but in the simplest scenarios (like controlling two separate train engines) they act so.

A single channel (dial) can control one or more motors, but in the latter case all motors will receive the same signal which means they will rotate in the same direction with the same percentage of their maximum speed - different motors can have different maximum speeds.
> 2 votes

---
Tags: technic
---


# Question
Title: What are the measurements of the different Lego instruction booklets?
I've noticed that there are at least three different sizes (eg 7.8"x5", 4"x5.8" and 7"x8"). Are there other sizes?

# Answer
> 1 votes
### Yes.

There are over 30 types, depending on box size. Some of them look more like books. Some of them are impractical, and haven't been reintroduced since their debut.

---
Tags: technic, instructions, city, friends
---


# Question
Title: EV3 won't connect through bluetooth anymore
I was using VS2015 (C#) to write simple programs for my EV3 using a bluetooth connection. This was working fine for several days and then suddenly stopped. I can't for the life of me figure out why. It's not my code, I don't think, because the sample program that came with the API also won't connect. However, I can connect with LEGO LabVIEW just fine.

What I've tried:

* Flashed the brick and updated firmware to 1.09H
* Reinstalled BT devices and drivers on host PC
* Reboots of brick and PC

I'm not receiving any exceptions on instantiating the brick, ConnectAsync(), nor any DirectCommand calls. Connections with USB do work fine.

Any ideas?

EDIT: I had typed firmware v1.06H (I believed this is what it was). It's currently 1.09H, although I did manually update to 1.07H to no effect.

# Answer
> 1 votes
You should always be using the latest firmware. If you have an EV3 brick that was produced in mid 2015 or later, it may have a newer Bluetooth chip that requires firmware v1.07 or higher. See https://bricks.stackexchange.com/a/7237/3498 for an unofficial firmware changelog.

If updating the firmware does not fix the problem then the name of the comm port probably changed. This is something like "COM1" or "COM5". Look in the Device Manager to see what comm port is assigned to your EV3 and make sure it matches your C# code.

---
Tags: ev3, bluetooth
---


# Question
Title: Torso and legs with different LEGO logos. Are they genuine?
I have a torso with rounded edges and "Lego" stamped on top. The arms not stamped. I also have a torso with straight edges and "Lego" stamped on top. The arms are stamped.

Are these both genuine?

I also have hips with 2 different logo's on them (see the image below). The one with the *LEGO* mark is not stamped on the bottom. The one with the *(c) LEGO* mark is stamped at the bottom.

Are both of these legs genuine?

# Answer
> 2 votes
Both rounded shoulder and sharp shoulder LEGO torsos are genuine (as long as the LEGO logo is on the neck-stud). They are just manufactured at different facilities. Most people never even notice the difference, but once you do, it's hard to un-see it. ;)

The arms with stamps were mostly seen on the early LEGO Collectible Minifigure Series, but later they were made the same as other minifigs with no stamps on the arms. This is likely because of the complaints from LEGO fans that they didn't like the unsightly stamps on the arms.

The legs are also genuine. Different orientation of the LEGO logo on them is very common, and also just means they made at different facilities.

Changing the orientation, placement, and even size of the logo is very common, and LEGO elements with these different variations are popular items to collect by those who are really into LEGO's history and unique elements.

# Answer
> 1 votes
Legs and arms do not need to be stamped on order to be considered genuine. LEGO considers a torso with two arms as a single assembly, just like a hip piece with two legs.

# Answer
> 1 votes
Meaning of different orientation of LEGO logo is pieces produced by using different molds. Both of are genuine. If you check several two by two slopes (item no:3040) you could easily find differences on rough diagonal surface of the part. This is because of using different molds on production stage. LEGO changes it's molds time by time. Especially on old sets, this alteration gives us the chance that finding out if some of the parts are replaced or all of them are originals that came with the set.

---
Tags: minifigures
---


title: Absolute position regulation NXC

text:
# Question
Title: Absolute position regulation NXC
I am trying to position the LEGO NXT motor exactly at a certain absolute angle:

```
PosRegEnable (OUT_A);
PosRegSetAngle (OUT_A, 0);
Wait (500);                  // to read sensor value
PosRegSetAngle (OUT_A, 90);
Wait (500);                  // to read sensor value
PosRegSetAngle (OUT_A, 180);
Wait (500);                  // to read sensor value

```

My Brick has V1.31 firmware.

When I load this program and run it, it doesn't display any error but the motor doesn't run.

Has someone experienced this before?

# Answer
> 2 votes
According to the docs (emphasis added):

> Warning
>
> This function requires the **enhanced** NBC/NXC firmware version 1.31+

Make sure you are using the **enhanced** firmware provided with NXC and not the *official* firmware from LEGO.

---
Tags: nxt, nxc
---


# Question
Title: Do WHITE LEGO elements fade or yellow while sealed for years, or do they stay their perfect white original color?
I was wondering if anyone has opened a sealed set like Taj Mahal or Star Wars UCS Imperial Shuttle after it had been sealed for years, and if so, were the white LEGO elements still perfectly white, or did they fade or yellow even while sealed? I'm debating about buying an expensive UCS Imperial Shuttle that's still sealed, instead of Bricklinking, just so I can have one looking brand new, but wanted to know if it might already have faded or yellowed even while sealed.

# Answer
> 5 votes
Lego bricks typically turn yellow due to a chemical change that occurs when UV light interacts with flame-retardants in the plastic. So bricks stored in darkness shouldn't turn yellow at all.

# Answer
> 4 votes
### Should be Fine

The sealing process, at least in the new bags without perforation, keeps the bricks safe from aging. The Taj Mahal should be just fine, and even opened, my Imperial Shuttle bricks are great!

In fact, all the newer bricks, 2003-2007, seem to be pretty yellow-proof. You'll typically only find those in much older sets.

Yellowing occurs because of UV interaction with the bricks. Box, indoors, away from windows, any of the above should keep them plenty safe.

---
Tags: colour, preservation
---


title: How to represent infinity in NXC?

text:
# Question
Title: How to represent infinity in NXC?
Is there anything like Java's `Float.POSITIVE_INFINITY` in NXC? How else can one represent the positive infinity in NXC?

# Answer
I don't believe that a constant or macro is available in NXC for positive infinity. C99 defines INFINITY in math.h, but the math module in NXC does not appear to include this.

NXC uses IEEE 754 floating point, so something like this should give you the raw value of infinity cast to a float:

```
int raw_infinity = 0x7f800000;
const float INFINITY = *(float*)&raw_infinity;

```

I don't have a way to test this currently, and I'm not sure how the underlying firmware and hardware handle special floating point values, so this may or may not actually meet your needs.
> 1 votes

---
Tags: nxc
---


# Question
Title: LEGO Minifigures Series 14 Female Ghosts!
Do all of the LEGO Minifigures Series 14 Female Ghosts have a smaller, more square-ish neck part?

# Answer
> 1 votes
I checked all of mine, and they the same smaller mark as well.

# Answer
> 0 votes
### Yes

I asked with my BIONICLE design friend, who asked his manager, who asked a guy on production, who... honestly, I don't know how many people were in the stream, but the answer came back as one word: Yes. That's all I know.

It's not a very detailed answer, I'll admit, but it is a true/false question.

# Answer
> 0 votes
I just checked a random handful of my collectible minifigs. Most of them have no black mark at all. Some of them, such as the Siren you posted, have a small black mark. Other recently produced minifigs do or don't have the mark: my Dr. Who figs have the mark, the Ghostbusters Firehall figs don't. Only the collectible minifigs seem to make use of the smaller mark, as far as I can tell. The standard figures have a larger mark.

---
Tags: collectable-minifigures
---


# Question
Title: How to find a set(s) contain most parts of my wanted parts list
I have a parts wanted list (in BrickLlink) and I want to buy a set contain most of my parts wanted list.

Does there is a way to import a part list and find which set(s) contain most of them?

# Answer
> 6 votes
I've never tried it, but I suspect you can do this with Rebrickable.com. It lets you upload MOCs, which must have an inventory. It then lets you see how close your collection comes to building that set, including some possible piece substitution (i.e. similar parts, related molds, ignore colour, etc). Finally, it recommends sets to buy to increase your total. To my knowledge it doesn't try to optimize the "purchase" list to maximize coverage or keep costs down, but it should at least give you some candidates.

For example, when I try to build this MOC, it tells me I'm missing a bunch of black pieces:

Then it suggests some sets I might buy:

Note that the suggested sets are not always practical.

---
Tags: piece-information, sets
---


# Question
Title: What is known of the capacities of the MINDSTORMS EV3 when it comes to interconnection with a network (WiFi, bluetooth)
What is known of the new MINDSTORMS EV3 capabilities when it comes to netwoked functions. What type of interface can be plugged to interact with a PC or portable device (smartphone/tablet)?

In term of interconnection (WiFi/bluetooth) and in term of protocols available what are the options?

Are there any libs (C/C++) which are already available and compatible with the brick?

# Answer
> 6 votes
The Mindstorms EV3 brick uses Bluetooth 2.1EDR. What protocol they use on top of that is still unknown, but will probably be released publicly by LEGO at some point. It's likely some compatibility with the NXT is possible (that is, an EV3 and a NXT bricks should be able to communicate together), but this is pure speculation and I doubt they just reuse the exact same protocol without at least expanding it.

For USB, apparently the regular USB port is 2.0, but there's also a host USB port which, according to the previous link, is only 1.1 (which seems strange to me, and the official PDF product sheet for the EV3 brick specifically mentions "USB 2.0 host enabling brick daisy chaining, wifi communication, and USB memory sticks") and can be used to daisy-chain up to 4 devices. The very fact they state a limitation hints that their software itself has this limitation, as I don't see any hardware reason to do so. This means that with an alternate firmware, you can probably do more.

WiFi is only possible using a WiFi dongle connected to the USB port, which seems to be allowed. If the host port is really 1.1, that may limit the speed to 12MBit/s. You can find its PDF product sheet here which says:

> The EV3 Wi-Fi Dongle fits with the LEGO® MINDSTORMS® EV3 platform and uses wireless communication. It plugs into the USB host port of the EV3 Intelligent Brick and provides wireless communication with a computer. A wireless access point is required between the LEGO EV3 Intelligent Brick and any Wi-Fi -enabled computer as well as your Apple or Android device. All you need to do is set up the connection inside the software and you’re ready to go!

Also, considering the OS is linux-based (on an ARM9 processor), and considering LEGO's history of letting people hack Mindstorms in any way they can think of... there'll probably a lot of other possibilities (USB Ethernet, for example).

APIs and/or libraries aren't available yet, and probably won't be until the kit is released, but it seems there'll be at least an official iPhone & Android app to control all robots you can make with the kit.

# Answer
> 3 votes
The new EV3 Intelligent Brick has the following announced features:

* IR sensor
* Bluetooth connectivity\*
* SD Card Slot
* USB Port
* Linux-based firmware
* Full iOS and Android compatibility out of the box

In terms of libraries for connecting with it - if it's based on a standard core, then I would assume that a standard bluetooth stack should be able to communicate with it, but unless it's based around an arduino core we will need to wait until full specs are released before the libraries catch up.

* Assumed based on current NXT feature-set and connectivity for phones.

# Answer
> 1 votes
A bit late but well:

For source code you can check out https://github.com/mindboards/ev3sources

The EV3 comes with:

* Bluetooth, two protocols on top of it, one used by the iPhone App and the other is RFCOMM with application data the same as over USB and TCP.
* USB: over HID
* TCP: Device uses UDP broadcasts to announce itself and can then be contacted over TCP.

You can plugin a WLAN Dongle into the USB Port or a USB-Ethernet adapter. It was the case that only a particular Netgear dongle was supported. Don't know if that has changed.

Protocol spoken is specified by this manual.

ev3duder, which I wrote as part of c4ev3, tries to detect an EV3 and can send system commands (e.g. Uploading/Downloading) or open a persistent tunnel which you can use to tunnel your own direct commands (check out moveEv3.pl for an example).

If you want to send stuff over USB, you got the `~/dev/lms_usb` device file. For WiFi, just open a socket and do your stuff. Bluetooth I can't recall, unfortunately. Check out ev3duder's source for specifics if you don't want to use it directly.

---
Tags: ev3
---


title: Programming with Lego Mindstorms EV3

text:
# Question
Title: Programming with Lego Mindstorms EV3
I know this question was asked in the past, but I want an up-to-date answer.

What is the best way to program with the NXT with a oriented object programming language? Ideally C#, C++ or Java (maybe Python).

I've search a bit, but I have difficulty to find what is popular today.

I'm really interested in Mindstorms, but I don't want to program with boxes.

# Answer
When we did NXT programming in university we used NXC (http://bricxcc.sourceforge.net/nbc/) as our primary language.

This is a C-stlye language, not exactly object-oriented, but seeing that NXT programming is practically equivalent to microcontroller programming, C is much better suited to this task in my opinion. In C you get a much clearer main loop that controls your robot, and I can't really see what benefits would object orientation bring to a platform that is clearly restricted in both input/output capabilities and computational resources.

But if you really need object oriented design, take a look at LeJOS: http://www.lejos.org/
> 2 votes

# Answer
You can use C++ with c4ev3, also available as Eclipse Plugin.

If you are ok with sending the commands remotely, you can even use any language that supports `popen()` like functionality, (which includes every useful language out there, with some bash-fu even Brainfuck). Check out moveEv3.pl.
> 1 votes

---
Tags: nxt, mindstorms, ev3
---


title: Controlling EV3 motors within VC++

text:
# Question
Title: Controlling EV3 motors within VC++
I've got an application within some VC++ software (BCI2000). This is running on Windows 7. Although BCI2000 can run elsewhere, I'd like to stay on Windows.

I've got an EV3 whose motors I'd like to manipulate within my existing application. I don't mind using bluetooth, wifi, or a wired connection, whatever is easiest.

What would be the best way to go about doing this? I've read about ev3ev and ev3 sources, both look feasible. I also stumbled upon this post detailing control of the motors using just xcode with nothing installed on the brick. That looks ideal to me but my attempts at just injecting that code into my VC++ project have persistent dependency failures that I'm trying to fix here.

Any recommendations on how I could go about this?

# Answer
> 1 votes
You can run C++ programs directly on the EV3 (Stackoverflow). An Eclipse plugin is also available.

If you want to run the C++ program on Windows and connect to the EV3 remotely you can use c4ev3's ev3duder, to establish a connection to the device and then keep sending direct messages to the motors over that connection. Check out `moveEv3.pl` for an example.

---
Tags: ev3, ev3dev
---


title: Scooby Dum LEGO character?

text:
# Question
Title: Scooby Dum LEGO character?
I like playing with LEGO sets a lot. I especially like the Scooby Doo sets. I'm wondering if LEGO has ever made a Scooby Dum character? Scooby Dum is Scooby Doo's cousin.

# Answer
One can never be certain about *everything* Lego has ever produced, but If you search on Brickset or Bricklink for the word "scooby" you don't, at this time, find anything except Scooby-Doo.
> 1 votes

---
Tags: minifigures
---


# Question
Title: Understanding the makeup of an XML .ev3p file
When you unzip an `.ev3` program, there are many `txt` and `xml` files that are inside. In particular, there is an `xml` file produced with the filename extension `.ev3p`, which seems to contain program instructions which the EV3 brick can then interpret and execute. I am interested in using these `.ev3p` files produced in order to analyze the correctness of programs.

To test this, I created two `.ev3` programs: one which moves forward 3 cycles, one which moves forward 5 cycles. Upon text-comparing their respective `.ev3p` files, I found :

```
<ConfigurableMethodTerminal ConfiguredValue="3">

```

in the first file and

```
<ConfigurableMethodTerminal ConfiguredValue="5">

```

in the second file.

However, there are other small, unexplained differences between the respective `.ev3p` files. I need to know:

* Is there any documentation that is provided by National Instruments that can give me insight into how these `.ev3p` files are produced and how they can be interpreted.

# Answer
> 10 votes
I personally doubt that there is any publicly available documentation of the contents of these files. However, you may gain some insight from the documentation in the "EV3 Block Developer Kit" available on the LEGO MINDSTORMS Download page.

Tip: rather than using the outdated copy of the EV3 software included in the EV3 Block Developer Kit, I have found that you can create a file named `MindstormsEV3.ini` with the following contents:

```
<?xml version="1.0" encoding="utf-8" ?>
<Tokens DeveloperMode="True" />

```

and save it in the LEGO MINDSTORMS EV3 program directory to enable developer mode on any installed version of the software.

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Tags: ev3
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title: Does this 2x4 brick exist?

text:
# Question
Title: Does this 2x4 brick exist?
I've been working on a little history project to make a shadowbox/display-type thing of all of the major evolutions of the 2x4 brick over the years. (I know this can get really in-depth, and I'm trying to hit major changes only, to preserve my sanity).

My question is this: is there such a thing as a 2x4 brick (it would be ABS) with the "Pat Pend" obscured (covered by a blob, denoting an updated mold), that has **tubes only**?

In other words--**no braces, horizontal crossbars, ridges of any kind** (no slotted tubes either), just like a 60's brick, but made **late** enough to have the "Pat Pending" obscured, but **early** enough to not have any added reinforcements.

Also, by all of this I mean a brick that would have been in normal sets, and not a sample or test brick.

It's getting frustrating, and I wonder if I have invented this category!

# Answer
### Yes. There is.

I have a few. They are really bad for connecting to things.

Like, BanBao bad. I can't really use them for anything.

But they do have the blobs.

So yes, there are those, and they are rare, for the same reason the "Pat Pending" ones are rare, mostly the age, and short transition period.
> 7 votes

# Answer
Leggodt.nl lists such a brick as part of their collection and also has photos of them. Here is the entry, and on this site you can find a good picture showing the brick and the obscured *Pat. pend.:*

(The entire site is a good source for what does exist.)
> 5 votes

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Tags: piece-information, history
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# Question
Title: How to motorize Technic 42040 Fire Plane
Where can I find instructions on how to motorize the Technic Fire Plane. We have the kit 8293 which contains a motor, battery box, lights and switch, but we have no idea how to attach them. Will there be instructions online somewhere, or do I need to improvise?

# Answer
> 2 votes
The retail box does not show the usual "+Power Functions" decorations on it so I doubt there are official instructions. Time to get your build on.

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Tags: technic, instructions, motor
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title: Need help identifying some sets

text:
# Question
Title: Need help identifying some sets
So I have a few LEGO sets that I bought at a garage sale. They didn't come with an instruction manual or anything but they are from 2011 and one of them has a white box that says 6049732 on it. Can anyone help me identify these sets or where I can go to identify them? Thanks. This is the first set.

# Answer
> 3 votes
I think you have bag #2 from this set: 60022 Cargo Terminal, based on the tan 4x6 base plates, the black 2x2 round plate with 4 arms and the red City minifig cap. I've also cross-checked the rim piece, the 2x3 Red plate and the 2x4 yellow brick.

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Tags: sets
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