# Question
Title: How do you repair yellowed or faded LEGO blocks?
In particular, I've had white blocks that have yellowed in places. Can the colour consistency be restored? Or at least improved?

I'd be more interested in people's actual experiences rather than simple suggestions.

# Answer
> 20 votes
When I first got my kids some LEGO I did it by bulk buying 25 kilo bags of used bricks off the Internet. Now these bricks had obviously been in outdoor sandpits, chewed by dogs, hidden under carpets - you name it.

We successfully restored almost all of them by by washing them in a bath full of a **Milton** solution, scrubbing each one with an old toothbrush and then leaving them to dry on a towel.

This cleared up some yellowing that we had thought was sun damage and fading, however there were some (especially some black pieces) that just looked off-grey and no scrubbing sorted them.

I would suggest trying this method, but if it is sun damage that is more than the outer surface I think you might not have any success.

# Answer
> 17 votes
I have used the Retr0bright method with great success for restoring yellowed bricks. Originally, this solution was hit upon by fans of retro computers wanting to restore old yellowed computer and game consoles to their original color. LEGO fans picked up on it and have had good results.

The solution is essentially hydrogen peroxide with sodium percarbonate added as a catalyst. The bricks are submerged in the solution and placed in UV light (sunlight or under a UV lamp). Depending on the strength of the solution and the light, the process can take several hours to a couple days.

Hydrogen peroxide is readily available, although in the US it is usually sold in a fairly weak 3% solution. Sodium percarbonate is the active ingredient in various "Oxy" detergent boosters.

The old Retr0bright site has information about the chemical reaction that takes place which restores the original bright color. Unfortunately the user discussions are not archived and do not seem to be transferred to the current site. The site owners do not recommend bleach for this purpose. Although a prolonged soaking in bleach solution can remove much of the yellowing, it will also leave pits on the surface of the plastic, causing it to become brittle.

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Tags: repair, cleaning
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title: Bridge from just basic bricks?

text:
# Question
Title: Bridge from just basic bricks?
I teach an after-school engineering class using LEGO bricks, one of our classes has the students build a bridge. Each student gets a custom set of about 150 2x4 bricks, about 300 2x2 bricks, and, if I'm feeling generous, about 15 2x8 plates. Although I've seen many fancy bridges made with technic parts, I've never seen an awesome bridge made with just basic bricks. I'm looking for a reference bridge to show the kids, after the build their own, what is possible. So, show me the best bridge (either a link to someone else's bridge , or a photo of your own) that can be made with just basic bricks!

Scope note: Most people don't have this custom set of bricks, so links or pictures of any bridge that uses almost no rare parts and use almost no technics would be cool.

Background:

LEGO Bridge Page: http://lego.sparre-andersen.dk//Transport/Broer/

Arch from archive

Cantilever from archive

Big: from archive

Sort of basic arch: from flickr

# Answer
> 6 votes
If you also want them to be aware of the solidity of their bridge, you may want to have a look at this contest.

Note that bridges made of stacked plates are much more solid than Technic ones.

# Answer
> 5 votes
Since you mention an engineering class, I assume you probably mean a functional bridge that can be tested for capacity.

This bridge may not withstand a great deal of weight, but it appears in a 1964 LEGO Idea Book and is created only from basic bricks available at that time. (LEGO did issue a more detailed Tower Bridge set a few years ago)

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Tags: building, bridge
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# Question
Title: Can I use two ultrasound sensors at a time?
Is there a way to use two ultrasound sensors on a Mindstorms NXT without them interfering with each other?

# Answer
> 6 votes
theres a *single shot mode* (at least when using NXC, NXT-G is very limited in fuctionality) for ultrasonic sensors. if you use that and don't read from two sensors at the exact same time, you can pass around interferences. to read more about that, please take a look at:

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Tags: nxt, mindstorms
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# Question
Title: What is the difference between train motors 88002 and 10153?
I want to motorize my Santa Fe Super Chief. Its original instruction mentions 5300 but it's marked obsolete on BS.com and now re-released as 10153.

In the same time 88002 costs few times less, e.g. $15 on Lego.com vs $55 on eBay.

So does it make sense to acquire more expensive 10153, or can just go for 88002? Are they compatible? What is the difference?

**Update:** Is the key difference in the way how does engine receive electricity? From metal tracks or inner engine (like Red Cargo train does)?

# Answer
> 10 votes
5300 and 10153 are from the former 9V train system and drew power from the metal tracks. They were controlled using a transformer attached to the tracks.

88002 runs on battery power from an onboard battery box. Trains with this kind of motor can run at a set speed, or can be controlled by adding IR remote controllers.

Regarding compatibility, the 5300 and 10153 require powered 9V track. They will not run on the new plastic tracks. The 88002 is the same gauge as these 9V motors, so it will fit and run on the 9V tracks.

LEGO is no longer making 9V train components.

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Tags: power-functions, trains, motor, set-modification
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title: NXT motor power accuracy

text:
# Question
Title: NXT motor power accuracy
When turning the motors, how precise is the speed parameter? I am programming in the NXC language (standard firmware) and wishing to know how many decimal points will be taken, if any, and whether the input speed will be truncated, rounded or neither.

# Answer
> 5 votes
From the page you linked to we can see that the NXC `OnFwd` method has the following parameters:

```
void OnFwd (byte outputs, char pwr)

```

The power or speed parameter is listed as a `char` type, and looking around elsewhere on the site we find the definition of the `char` to be:

> In NXC the char type is a signed 8-bit value. This type can store values from SCHAR\_MIN to SCHAR\_MAX.

This means it can hold an integer value between -128 and 127.

It cannot take any decimal values.

I assume that a `char` was used over an `int` as they only need to support values between -100 and 100 in this method.

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Tags: nxt, mindstorms, programming, motor
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# Question
Title: Is it unethical to distribute 3D models of Lego bricks?
So say that I use LeoCAD to export some brick models to Blender. Would it be unethical to modify the models in various ways (tris to quads tool, subsurfacing, textures, rigging, etc.) and then publish them to the internet, assuming that I do not try to profit from them in any way?

# Answer
Almost certainly no, but with some caveats:

The LeoCAD parts library is based on the LDraw parts library, which has a Legal Agreement here.

The vast majority (and I would assume the entire subset used by LeoCAD) are covered under the Creative Commons Attribution License 2.0:

**You are free:**

* to Share — to copy, distribute and transmit the work
* to Remix — to adapt the work
* to make commercial use of the work

**Under the following conditions:**

* Attribution — You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the works).

However there are parts in the library that are not covered by the LDraw Contributor Agreement (CA), and these are covered by the more restrictive NonCA agreement. You are expressly forbidden from sharing, or making derivative works of these parts (creating 2d renderings of the elements isn't considered a derivative work, but converting the parts to a different format is).

All part files should have a license comment in their header stating either:

```
0 !LICENSE Redistributable under CCAL version 2.0 : see CAreadme.txt

```

or

```
0 !LICENCE Not redistributable : see NonCAreadme.txt

```

You should check those parts you wish to adapt, and proceed accordingly.
> 8 votes

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Tags: cad
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title: LEGO games for grown-ups?

text:
# Question
Title: LEGO games for grown-ups?
Are all LEGO Boardgames more or less for children, or are some of them suitable for grown-up, more expert players? (Everybody likes relaxing with a simple game, but are any of the games a bit more challenging?)

# Answer
The most obvious answer is probably the LEGO Heroica range, especially when played in "Campaign" mode; for more details see our Heroica tag wiki.

There are also a few examples of "Expert" rules that others have come up with, including our very own Joe Wreschnig's set on his dedicated site.

> Advanced Heroica PDF by Jason Glover/GreyGnomeGames (archived page)

Both of these make the ruleset more complicated and can encourage more of a team play than the usual competitive play that my kids make it.

LEGO Creationary is another game where the modelling requirements make it a slightly less child friendly game than some of the others.
> 14 votes

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Tags: lego-games
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# Question
Title: What is the most compact way to make a flat six pointed star in LEGO?
I spend a lot of time building in Micro scale (I maintain the Micropolis collaboration standard) and my partner is trying to figure out how to build the most compact, or smallest, six pointed star possible to fit into one of her builds. We've played around with friction set cheese wedges similar to this example but were curious if anyone has any other ideas. We're open to using parts in System, Technic, Clickits, or even Znap or of course any combinations thereof.

# Answer
> 14 votes
Hexagonal symmetry and angles in 15, 30 and 60-degree proportions are scarce among LEGO elements.

I think the smallest single piece that approximates a six-pointed star is the basic flower:

I myself don't practice freelance brick modification, but someone with fewer scruples might easily trim one of these into a 6-pointed star shape.

Another piece that has hexagonal symmetry is the old pulley wheel:

The holes are arranged at 60-degree intervals around the center. Putting two of these pulleys together and inserting half pins into the holes will give you 6 studs arranged at what could be the points of a 6-pointed star:

I added a 1x1 round plate to three of the studs to offset the gear shift handles. This construction is a little shaky, as the half pins will rotate. Not sure if it's compact enough for micro-scale - the star ends up about 2.5x2.5

You could get a 6-pointed star of about the same size using two triangular roadsigns:

These have clips on the back. Putting them face-to-face would give you a clip on the front of the star, and you'd have to find a way to hold it in place, but it would have the advantage of being fairly thin. The color options on these pieces are limited, though.

# Answer
> 7 votes
A smaller six-pointed star which only uses cheese slopes has been achieved in the MOC below:

Flickr: The grand entrance 6, qi\_tah

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Tags: building, design
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# Question
Title: Where can I find "hacker" information about the NXT?
I want to know if, and where, is some *extremely* detailed hacker information on the Mindstorms NXT 2.0. Things such as the processor, flash memory, and RAM information, GPIO or I2C support, custom firmware mods, maximum amperage draw, motor types (AC or DC, stepper or standard), sensor details (ultrasonic and color), and all of the other things that hacker types love. Don't get me wrong, the NXT is incredible as it is, but I would be happier getting one knowing that I have some room to mess around with it.

# Answer
You can start with the Hardware Developer Kit which includes "documentation and schematics for the NXT and related sensors", supplied by The LEGO group to help you "design and develop your own sensors and actuators \[motors\] that can interact with the NXT".

I've not really looked at the latest ones, but the original O'Reilly Unofficial Guide to LEGO Mindstorms was very good, and covered things like creating your own sensors for The Robotics Invention System - looking at the descriptions of the newer ones, they don't appear to require soldering irons or alternative programming environments :(.
> 11 votes

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Tags: nxt, mindstorms
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title: Access hatch in a wall?

text:
# Question
Title: Access hatch in a wall?
Working on a 10 stud by 10 stud Square bell tower for my annual project. Need to create a access panel/door. Any tricks that can be done so it's hidden or at least not easily noticed?

I need to hide a small MP3 player and speaker inside and need access to the player to turn it on and off.

# Answer
> 7 votes
I would suggest not using hinges of any kind, but just making a plain panel with a tile on top, resting on a tile in the wall. For an example from LEGO itself, have a look at booklet 2 of the instructions for set 7094. Notice they use panels instead of flat tiles which is even less visible from the outside (although they did it not for that reason but to make sure it was easier to remove).

In your case, you'll want to block it from behind (with slopes at each corner for example) as you don't want it to go into the structure.

To remove it, you'll either need to draw it by some protruding fixture if you can fit one in, or push it from the inside by another mechanism (for example, pushing on something on the top would activate a lever which would push the wall)

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Tags: building
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# Question
Title: How can I make a LEGO heroica scale fountain of youth using bricks from Fortaan or Waldurk?
I have started collecting heroica and I thought "wouldn't a fountain of youth be superb!" but I only have Fortaan and Waldurk... any ideas?

# Answer
Thought I'd finally step up to the plate - here's my first attempt.

On the basis that the Fountain of Youth is probably an end goal rather than something you'd come across on the way somewhere else I've gone for an 8x8 base, but as we're limited to these two sets I've had to go with grey - I could probably have gone with the 4x4 blue plates, but felt that might limit other options, and wanted the figures to be able to move around the fountain a bit.

I've added the goblet as a collectable treasure that could have a "healing" rule for use in campaigns:
> 6 votes

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Tags: building, heroica
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title: How can I make micro-scale water?

text:
# Question
Title: How can I make micro-scale water?
This is totally boring:

How can I add some variance to it that helps to distinguish a rippling lake from a raging ocean from a fast-moving river, while keeping a look that's appropriate for micro-scale landscapes?

# Answer
> 14 votes
The 1x1x2/3 slopes would be ideal for making waves, etc.:

and or the 1x2 options.

Along with some blue tiles you could make some great waves:

Obviously, if you don't want them breaking, keep the white fronts blue.

Also, if you have some Navy blue tiles you can create currents of colder water - if you've ever watched large bodies of water you'll notice they have strips of different shades running through them.

Stick to tiles on the plate rather than the 2/3s height for lakes, or for some good ripples use the Round Dish 2x2 Inverted:

# Answer
> 3 votes
Try using combos of Trans-clear and Trans-blue studs to make a nice, clear foaming water affect. Studs can be bought in extreme masses on Bricklink for like, 1¢. So there's no trouble.

# Answer
> 2 votes

# Answer
> 1 votes
Use a blue stud and put a flat round Lego brick on top of it to make the beautiful ripples.

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Tags: building, micro-scale
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# Question
Title: Are there any AFOL clubs in the Atlanta area?
Are there any AFOL clubs in the Atlanta area? If so, do they have current contact information? I did some Googling but the results were inconclusive and I thought I'd shoot this out to the community.

Sorry if it's too specific or localized, but that's good I guess.

# Answer
There may not be anything aside from the North Georgia LEGO Train Club, but it looks like you could start one from the Waiting List - AFOL there also appears to have been a newsgroup lugnet.loc.us.ga.atl.
> 2 votes

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Tags: afol
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title: How can I draw a microfigure on paper?

text:
# Question
Title: How can I draw a microfigure on paper?
I am a great drawer, but I cannot draw microfigures! You may think that because I am young I won't be great I really am, but I need help drawing this, on paper.

# Answer
Since you'll be working at a scale you may prefer to use graph paper. You can print your own if you don't have any, this will make it easier. Use a ruler, pencil and a rubber to draw your microfigure.

A microfigure is roughly 2/7 legs, 2/7 torso and 3/7 head high, It should also be 3 squares wide. You may find the diagram below makes it easier to visualise:

At this stage the most important thing to concentrate on is symmetry.

> Symmetry is common in nature, human beings and even more so with Lego. Bricks wouldn't be as compatible as they are now if they didn't have a sense of symmetry.

For now, concentrate on the vertical symmetry (top-to-bottom). In my sketch I've drawn out the three boxes first and added a few rough outlines within the guidelines. These guidelines can be erased later when you have finished.

If you can draw Microfigures, you can draw Minifigures. All it takes is a change of scale.
> 14 votes

# Answer
Take a look at:

1. How to Draw a Lego Minifigure with Easy Step by Step Drawing Tutorial
2. How to Draw LEGO Men
3. How to Draw a LEGO

Personally number 3 looks like the best bet to me.
> 4 votes

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Tags: microfigure
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title: TTF font for LEGO bricks

text:
# Question
Title: TTF font for LEGO bricks
I'm in the process of reprinting labels for the zillions of LEGO storage drawers in Junior's toy room.

I'm not looking for a font that depicts Latin alphabet characters seemingly built out of LEGO bricks, but instead a font which code points map to drawings of LEGO bricks, plates and tiles. Similar to windings, but with LEGO part shapes instead of smileys.

I believe there is at least one font where letters are actually LEGO parts. Does anyone know where I can find it?

# Answer
I searched around on dafont.com, fonts.com, and myfonts.com but didn't find anything. However, I found this post on the eurobricks.com forum from 2008, which links to this page:

http://www.house42.com/2008/09/17/legorama-fontstruct-font/

This font (and its variants) are all available for download as TTFs (free account registration required):

The fonts are available under the CC BY-NC-ND 3.0 license (Attribution required, non-commercial use, no derivative works).

Alternatively, if you're feeling really ambitious, here's a tutorial on how to make a LEGO font yourself.
> 4 votes

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Tags: storage
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# Question
Title: Will it be fun to go to Legoland with my family?
I am 31 years old . My elder sister and mother are going to visit me. I want to see whether it is suitable to bring them to LegoLand.

# Answer
> 5 votes
My wife and sister-in-law enjoyed our trip to LEGOLand with our sons, everyone enjoyed the models, however not everyone was as keen on the rides, you mileage without kids to share the rides with may be different.

The question then comes down to whether you feel the model world is going to justify the entrance fee, personally I found the UK park to be (comparatively) expensive compared to other theme parks in England.

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Tags: legoland
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title: What's the thing between the pant legs?

text:
# Question
Title: What's the thing between the pant legs?
What is the piece that holds the pant legs together called? Is there an "official1" name? Or is there just a commonly agreed on term?

1Official meaning something mentioned, even in passing, by Lego in some way.

# Answer
They are referred to as "Minifig Hips" almost everywhere: \[partlink:970:4\].

The LEGO Pick-a-brick service doesn't sell them without legs, and just refers to the whole construction as "Mini Figure Mini Lower Part":
> 16 votes

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Tags: minifigures, part-identification
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# Question
Title: NXT brick output ports not working properly
My NXT brick will not let motors run. When I download a program the motor will move forward and backward and then stop - sort of a wiggle. Another motor will not work at all. This happens for all three ports. Any suggestions.

# Answer
> 4 votes
Try putting a Wait block after the motor block. Set it to wait for 5 seconds.

I think your program just terminates after one block. Please post your program next time you have a mindstorms question.

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Tags: nxt, mindstorms, programming, motor
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title: Lego set for 17 year old

text:
# Question
Title: Lego set for 17 year old
This might sound a little bit silly, but I'm 17 and I've never built a LEGO toy, so I was looking for a first one, to see what it's about. What sets would you recommend I should look at, that are complex enough for someone my age not to get bored?

I wouldn't really get an NXT, because I don't want to program a robot, I just want to build something, and I think an Arduino would be cheaper and more complex. Bionicle and Architecture seem interesting, but Technic looks like the most complex of them all.

So... what sets should I look at?

# Answer
You're probably the only one who can answer that question, but here are a few thoughts anyway.

If you're interested in mechanic complexity and how machines work, Technic is indeed a good way to go. And as you hint, it can evolve into robotics, whether with a NXT or with anything else you fancy.

If you're after building complexity, I wouldn't recommend the architecture sets. The few I build weren't very challenging, and I find their price a bit on the heavy side. The bigger ones (21005 - Fallingwater or 21010 - Robie House may be more challenging, though.

However, sets with a high number of parts will usually mean the build is more complex. For example, 10214 - Tower Bridge has 4287 parts, and if you compare its price with the 2276-parts Architecture Robie House, you'll find it much more interesting.

Similarly, the various modular buildings also have high parts counts and are fun to build and display afterwards; plus, they go well together when you get the chance to have more than one.

As an aside, notice the "display" aspect I mention is important too - what do you want to do with the set you'll end up buying? If you're after replay value (creating new things constantly, the Creator theme has great sets with good play value, which are reasonably priced.

On the other hand, if you're concerned about your set keeping some value, or if you're a fan, license sets may be a good choice, especially Star Wars which also has some very big and complex sets.

Last, keep in mind LEGO also give age ranges for its sets. They're estimates, but a set marked 16+ is likely to be more challenging to you, so you'll want to look for these. You can easily browse the sets by age on the online LEGO shop, and even set limits for price and number of parts.

In any case, whatever you end up buying, don't hesitate to come back and share your own experience.
> 21 votes

# Answer
It's an interesting question.

As Joubarc stated there are multiple approaches here. But from my personal experience I would recommend a **graduated** approach into the Lego Technic.

You should start with the sets on this page to see it you can find any kind of interest and to ensure you are not simply discouraged by the Lego Technic models.

If you enjoyed the simplest models at least a bit, you shouldn't stop until you have built the most challenging ones. The reward in completing and discovering them is way higher. To me the most enjoyable model was the 8880 Super Car replaced by the more modern 8070 Super Car. Although the new 9397 Logging Truck seems to beat it when it comes to complexity and functions.

But first you should try some simpler and yet enjoyable models. I know people who like the racing cars more than anything else. I like anything with good and interesting parts/mechanisms. If you like the construction vehicles more than the cars you will find a few good sets. The 8043 Motorized Excavator being the coolest construction themed set for me.
> 11 votes

# Answer
Architecture set - White House. This is the first lego I ever built (got as a gift from wife). Loved it. Right amount of pieces, right amount of time - ~3-4 hours. Enjoyable time well spent. Recently disassembled with help of a brick tool, packaged it up and sent it to my brother so he could enjoy as well - he was a lego kid, I missed out on that when I was a kid.
> 9 votes

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Tags: sets, shopping, electronics
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# Question
Title: Is "public transport" train compatable with Lego City track?
Among other things, set 8404 contains a train but it doesn't come with any track pieces (see set 7499). Is this train compatible with these Lego City tracks? I see where it's more of an electric trolly and if it's not track compatible, is it at least wheeled?

# Answer
It uses train wheels which means it should work on Lego track.

Sources:

Bricklink set inventory

LEGO Building Instructions lookup
> 9 votes

# Answer
It is designed to handle curves that are found on CITY track. Here is the detail from middle car. There is tongue and groove that allows the middle wheels to slide left and right to enable curves. I will post a video of a powered train pushing it, if needed.
> 7 votes

# Answer
To a degree, Yes. The tram works well on straight pieces of track. It doesn't look like the tram was designed to be used with CITY track.

The wheel axles are fixed to one point so they cannot navigate curved pieces of track easily. A simple modification should be able to fix this.
> 4 votes

# Answer
The wheel used are smaller than regular train wheels and are usually never used in train sets; but more for smaller train-like stuff (Spider-Man metro, Indiana Jones mine cart, track buggy, track maintenance vehicles...)

So they will work on regular track, but their smaller size mean they're more likely to derail, and they have more friction around the axle than normal train wheels. Straight track is definitely OK, curves will presumably be good too, but be careful around switches.

In any case, a lot of fans use the same wheel to build their own trams, and some even manage to motorize them.
> 2 votes

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Tags: compatibility, city, trains
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# Question
Title: How accurate is the ultrasound sensor when moving?
Can I use an ultrasound sensor while the Robot is moving, or will it give bad data?

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

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

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

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

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

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

The first rule is, as always: Experiment on your own! For more resources, try the LEGO NXT Hardware SDK or at least the pictures in this german paper, pages 24, 27ff.
> 12 votes

# Answer
The ultrasound sensor will only be affected by the rate in which it captures and processes data, which could be a matter of milliseconds.

Supposing the ultrasound sensor captured data at one second intervals whilst moving towards an object at a rate of ten inches a second. If the rate at which it was moving was consistent the sensor would report measurements of say 60, 50, 40, 30 inches. This is not 'bad data', it can be considered insufficient depending on objective.

LEGO haven't specified the rate at which the ultrasound sensor processes data, if it hasn't been documented, you might want to try a couple of controlled experiments to see how it is affected by motion.
> 4 votes

# Answer
The shooterbot, one of the robots that can be built from the instructions in the nxt 2.0 set, uses this sensor while rotating in place, which proves this works pretty well.

please note that your results might be different, depending on the angle, speed of movement and distance of the objects you're measuring. Basically, there's no problem - but the best way to find out is to start building ;)
> 2 votes

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Tags: nxt, mindstorms, piece-information
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title: LEGO for a 1 year old

text:
# Question
Title: LEGO for a 1 year old
I have a son who has just turned one. I like my LEGO and my desk at work is covered in minifig's etc, the problem is my wife isn't as keen on them. I was wondering can anyone recommend a set that would be appropriate for me to get for my son so I can bring my hobby home without feeling the wrath of my wife, or is it a bit too soon to introduce him to LEGO?

# Answer
LEGO Group also did a range called LEGO Baby or Primo, which was pretty much suitable from birth.

It's not currently in production, but does come up on ebay and the like now and again, and is slightly inter-usable with Duplo and hence standard LEGO blocks.

Items ranged from things like this rattle, with chewable petals:

To the more "advanced" building sets:

My sons both enjoyed their Stacking Jungle Set, and the Bathtime Boat is still going strong ;)
> 11 votes

# Answer
LEGO bricks aren't suitable for children under 3 as they are considered a potential choking hazard.

LEGO also sell a DUPLO brand of construction toys which are twice the size of regular bricks. DUPLO bricks are designed for children aged 1½ to 5 years old.
> 12 votes

# Answer
There is also a non-Lego product from Megabloks that is really good for young children. They studs on those blocks are rounded so they're easier to kids to get them to "lock" together. While not as sturdy as some of the Lego products, they do seem appropriate for real young children.
> 7 votes

# Answer
In addition to DUPLO, there is also QUATRO. They are, as expected, 4X the size and impressively compatible with standard sized and DUPLO. I inherited some, so have no idea if they are still made or sold.
> 6 votes

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Tags: sets, shopping
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# Question
Title: Is the 3rd party vendor Amazing Armory still around?
I heard that he was a scammer, but he made some good stuff and quite a few people have some of the great visors and guns he made.

# Answer
> 3 votes
I realize that it's a late answer, but ToyWiz and BrickArsenal.com just started carrying this line, and Amazing Armory is active on Flickr. Also, Firestar in the UK carries it. I hope that helps.

Also, I work for ToyWiz.com and Brickarsenal :)

# Answer
> 2 votes
the most complete info i found was on brickblogger.com. the amazing-armory homepage still isn't online ("coming soon") - just like it was about a half year ago when the article was written. at that time you could buy parts on bricklink.com and firsestartoys.com where i can't find them today.

the unavailability on bricklink in addition with the still-not-online webpage pretty much sounds like amazing armory is out of business - but i don't have facts that prove this speculation.

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Tags: shopping
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# Question
Title: Measurements (LDU) of Lego tracks Set 151
I have an old set of 7851 curved tracks. I want to use the outer tracks (the ones with the bumpy surface). If I was to put one end down on a baseboard so that is tangent/parallel with the grid of studs, how many LDU in the X and Y direction would the other end be?

I'd also like to the know the X, Y cartesian coordinates (in LDU) of the middle 2 slots as well.

# Answer
Well, obviously one way to measure that would be empirically - you have the tracks, you have the baseplates...

As for the maths, let's see... a full circle of these tracks has a diameter of 5 straight tracks as measured from the centre of the sleepers, that translates to 80 studs. The radius is 40 studs, or 800 ldu.

The outer, ridged track, is 2 to 3 studs further depending on which border you consider (and assuming you want borders instead of stud positions). So the radii for the border of that piece of track are 840 and 860.

So, assuming the track circle is centered around (0,0), and using the usual way of considering circles in math (counterclockwise from (1,0)), your first piece of outer track starts at (820,0) and (830,0).

There are 16 segments of track to a full circle, so the angle for one segment is 22,5°, or pi/8. So the end of your first track part is at (840\*cos(pi/8),840\*sin(pi/8)) to (860\*cos(pi/8),860\*sin(pi/8)), or (776.06,321.45) to (794.54,329.11)

Expanding further, you get the following segments for the short border of the outer track:

1. (840.00,0.00)-(860.00,0.00)
2. (776.06,321.45)-(794.54,329.11)
3. (593.97,593.97)-(608.11,608.11)
4. (321.45,776.06)-(329.11,794.54)
5. (0.00,840.00)-(0.00,860.00)
6. (-321.45,776.06)-(-329.11,794.54)
7. (-593.97,593.97)-(-608.11,608.11)
8. (-776.06,321.45)-(-794.54,329.11)
9. (-840.00,0.00)-(-860.00,0.00)
10. (-776.06,-321.45)-(-794.54,-329.11)
11. (-593.97,-593.97)-(-608.11,-608.11)
12. (-321.45,-776.06)-(-329.11,-794.54)
13. (0.00,-840.00)-(0.00,-860.00)
14. (321.45,-776.06)-(329.11,-794.54)
15. (593.97,-593.97)-(608.11,-608.11)
16. (776.06,-321.45)-(794.54,-329.11)

Hopefully that makes sense. Watch out, these are the coordinates of the borders; for the coordinates of the studs (that is, the center of the studs, which I think is more interesting, but I don't know what your goal is) we'll have to use a radius of 850, and move 10 ldu along the tangent to find the stud. So to find the stud after the segment, we'll do (850\*cos(pi/8)-10\*sin(pi/8),850\*sin(pi/8)+10\*cos(pi/8)). For each segment N starting from 1, the studs are as follow:

* start stud: (850\*cos((N-1)\*pi/8)-10\*sin((N-1)\*pi/8) , 850\*sin((N-1)\*pi/8)+10\*cos((N-1)\*pi/8))
* end stud: (850\*cos(N\*pi/8)+10\*sin(N\*pi/8) , 850\*sin(N\*pi/8)-10\*cos(N\*pi/8))

End the two studs in the center of the track are basically and end stud if the angle was pi/16, and the start stud of the next track, or:

* first middle stud: (850\*cos((N-1)\*pi/8+pi/16)+10\*sin((N-1)\*pi/8+pi/16) , 850\*sin((N-1)\*pi/8+pi/16)-10\*cos((N-1)\*pi/8+pi/16))
* second middle stud: (850\*cos((N-1)\*pi/8+pi/16)-10\*sin((N-1)\*pi/8+pi/16) , 850\*sin((N-1)\*pi/8+pi/16)+10\*cos((N-1)\*pi/8+pi/16))

The four studs of the first part of track are thus at coordinates:

* start stud: (850.00,10.00)
* first middle stud: (831.72,175.63)
* second middle stud: (835.62,156.02)
* end stud: (789.12,316.04)
> 5 votes

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Tags: building, piece-information, trains
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title: Explaination of LXFML file contents

text:
# Question
Title: Explaination of LXFML file contents
I am interested in writing a game that interprets LXF files into worlds (to create a game such as Lego Universe). After finding out how to extract the LXFML file from the LXF archive, I need to know how to interpret the contained LXFML file. Are there any detailed descriptions of how the LXFML format works?

# Answer
> 13 votes
The LXFML file is an XML document, and there's an XSD document that you can use to validate any LXFML file, along with a textual description of the tags on the LUGNet forums supplied by the LDD Team a few years ago:

> LXF files - info and XML schema

The key parts of the LXFML you're going to be interested in start with the `<Scene>` element, which contains one or more `<model>` elements, which in turn contains one or more `<group>` elements, which are made up of `<part>` elements.

The tricky part is getting from a `<part>` element to an actual model:

```
<Part refID="0" name="m3680_turn_plate_2x2__lower_part_0" designID="3680"
      materialID="1" assemblyID="74340" assemblyRefID="0"
      angle="0" ax="0" ay="1" az="0" tx="0" ty="0" tz="0" />

```

As you can see, the Design ID corresponds to a LEGO element \[part:3680\] so you'll need some way to get from those to a suitable model - I recommend taking a look at either:

* BricksViewer \- A Java app for viewing .lxf scene files - also has a brief discussion of the .lxf and .lxfml formats.
* LDXNA \- An XNA library for importing LDraw models - it does include an .lxfml document in one of its examples, but I don't recall it using it - however it does show you how to convert the LDraw parts library into a usable format.

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Tags: software, cad, ldd
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# Question
Title: How do they decide when to remove an element from production, and what happens to the molds when they are retired?
We all know certain LEGO elements are no longer being produced. How do they decide when to remove an element from production, and what happens to the molds when they are retired?

# Answer
I can't find a link to substantiate this, but a quality assurance representative from LEGO mentioned at a BrickWorld presentation a few years ago that worn out molds are buried on the factory property in Denmark in concrete. If anyone else can find substantiation for that, I'd love to see it.
> 7 votes

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Tags: piece-information, history, manufacturing
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title: What are the female parts called?

text:
# Question
Title: What are the female parts called?
What is the proper term for the "female" section of the piece that the "studs" insert into? I have heard "pipes", "tubes", "underbits". Is there an actual term for the female section?

# Answer
> 15 votes
Chapter 1, Page 4, The Unofficial LEGO Builder's Guide:

> The *tube* is the other half of the mechanism that helps bricks stick together. Tubes capture the studs so that you can join LEGO elements and know they won't fall apart.

# Answer
> 8 votes
Bricklink (at the time of writing) has 5 catalog items using the term 'stud receptacle'.

# Answer
> 4 votes
Members of the French club FreeLUG refers to these as *antistuds*, and there is at least one LDraw part that uses that same naming. Considering a lot of other parts don't, however, it's probably not widely accepted. And it's not valid at Scrabble either.

You could also use *mortise* by analogy with the woodworking assembly (a stud is also usually called *tenon* in French), but again, I've never heard it in LEGO circles. *Slot* might be appropriate too.

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Tags: terminology
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# Question
Title: NXC Saturation algorithm for limiting motors?
What is a good algorithm in NXC for control saturation? I want to make sure my motors don't turn past a certain angle, or they will break the model. I could do something like:

```
if (angle > 45) {angle = 45;)

```

But that would be a hard limit. I'm looking for a smoother limit.

# Answer
> 2 votes
By "smoother limit", if you mean "when it gets closer to the limit, it will softly land there by slowing down" then: I recommend using PID control where the response (how fast the motor is moving to the limit) is controlled proportional to the error (how far away from the limit you are).

Wikipedia has a good intro to PID control: http://en.wikipedia.org/wiki/PID\_controller

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Tags: nxt, mindstorms, programming, nxc
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# Question
Title: How can one find old archived issues of LEGO Mania Magazine?
Do any libraries contain old archived issues of them? Preferably ones on the WorldCat system?

I'm not sure if my limited storage space can handle more LEGO Mania magazines, so I'd prefer a format that's either digital or that one can easily check out from a library.

# Answer
There is currently one public library in the WorldCat system that has cataloged LEGO Mania Magazine, but it does not have it available in digital form.

Other LEGO Club magazine titles have been collected by some WorldCat system libraries, including:

Brickmaster Magazine

LEGO Club Magazine

LEGO Magazine

None of these titles appear to be available in digital format from any WorldCat libraries at this time.
> 4 votes

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Tags: lego-group
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# Question
Title: New ways of connecting levels of multi-story modular buildings
Compare these two instructions from the Green Grocers and Pet Shop modular building and you may notice (other than the background colour) that the top of the walls of the buildings are both arranged differently:

Tiles are raised at certain lengths of the wall to ensure the floor above will stay in place.

The floor above is secure using the relatively new 92593 modified plate. The new plates occasionally 'lock' into the floor above when it's removed, leaving an impression of where the plate once was. However few pieces are required.

I'm building a multi-story police station with a large area (32X62) and I'm looking for a suitable way of connecting floors with as few bricks as possible.

# Answer
Two ideas I can think of, which are not using "tiles" as such, but similarly flat surfaces:

* Technic beams - holes attached to studs of the lower part of the building, and in some holes (which have to be above tiles), pegs/axles for the upper part to fit into.
* 1x1 "cheese" slopes - and inverted on the upper part (or use regular inverted 33° slopes), which makes the upper part fit in the lower as if in a funnel. (Not very different from using tiles)
> 4 votes

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Tags: design, moc, modular-buildings
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# Question
Title: Is it possible to build simple logic gates with LEGO mechanics?
I built a simple bitshifter in Minecraft yesterday. I wondered if something like this could be built with LEGO?

Maybe there is a possibility to build gates with rubber bands and those movable mechanic stuff. Did anyone of you do something like this?

# Answer
Various people have done this - however most of the links seem to point to a \[then defunct\] blog by Martin Howard (Randomwraith) from 2004.

A more recent, and available, post on this, using newer pieces can be seen here:

> LEGO Logic by Keshav Saharia

Based on a lack of gears and rack and pinion elements, Keshav decided to rebuild the logic gates using an approach based around levers. Extra care was taken to ensure that the movements were uniform so that the outputs moved the same distance as the inputs.

Starting with the simplest gate, a NOT Gate was built:

Then going back to first principles, a NOR Gate:

Combining a NOR with two NOTs gives an AND Gate:

Finally Keshav built the XOR Gate out of 3 NORs and 2 NOTs (or 2 NORs and an AND):

All images used with permission
> 59 votes

# Answer
Not directly an answer, but I thought that people interested in this question would also be interested in an inspirational post...

I've seen a binary calculator like this live and have since then thought on building it with lego. Ah, sweet plans...
> 6 votes

# Answer
There's this project, and with a mechanism like that you have a pretty high limit on the complexity of what you can do:

http://www.youtube.com/watch?v=SYi9sJkS19Q
> 6 votes

# Answer
Credit where it’s due, Keshav Saharia’s gates were an attempt to simplify those found here:

http://www.randomwraith.com/logic.html

If you look carefully Keshav's gates you'll see that they suffer from a fundamental flaw in that they can't be reset, the input rods are completely decoupled so pulling them out does nothing.

RW
> 6 votes

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Tags: technic, building, electronics, mechanical
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# Question
Title: How does LEGO decide it needs a new element?
Aside from the need to add licensed series specific pieces, how does LEGO decide it's time to introduce a new shape to the element palette?

# Answer
This may not really qualify as an answer, but basically I believe designers are responsible for calling for new parts.

For each new part, a production cost is calculated, which takes into account a lot of factors. There were talks a few years back about how they had recently changed these rules, but they aren't public (to the best of my knowledge). What is more or less certain however is that an element which fits well in the system has considerably more chance of being accepted; that is, I suppose the calculated cost is lowered to reflect its usefulness. That's why a lot of recent new parts are just of the "it so obviously makes sense, why didn't they do that before"-kind (1x3 tile, 1x1 bricks with 1 knob,...).

So the designer willing to commission a new part for one of his sets will need to support that cost as part of the cost of his set, which is imposed to him. I guess there are much more rules than that (if multiple designers agree on a part, for example), but that's the basics of it.

Also, note that producing an existing part in a new colour follows the same rules to an extent. It's calculated cost is higher than an existing colour for that part.

To summarize: each existing part has an associated production cost which the designers must take into account when creating a set. Non-existing parts are similarly associated a cost, which is calculated according to a lot of rules/factors which aren't public.

Even the costs of existing elements show subtle variations: some colours are cheaper than others, for example; or older elements may be more expensive because moulds aren't optimized (one known case is the Technic axle 5 which is cheaper than the 4 one, because there are twice as many of them on a mould).

Last thing, more as an aside: the cost of the first part in a model is also higher than the next ones, because it helps production to have more similar parts. For example, 7945 Fire Station doesn't have any regular 1x2 red or white bricks - since they have 1x2 bricks with groove for the doors, they used these everywhere a 1x2 was required - even if no groove was needed. That way the number of different parts in the set is lower.

Edit: here is a very interesting video on how they prototype the new elements. Notice at the beginning of the video, the designer explicitly mentions he couldn't get the shape he wanted with existing elements, so he had to have a new one made. This was for a license set (cars), so again the decision in this case may be easier to take.
> 12 votes

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Tags: manufacturing, lego-group
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# Question
Title: Any good Lego body decal templates or printing services
I was wondering could anybody point me in the direction of a good online service that prints minifig decals? I have no problem creating the designs etc but getting somewhere to print them is very hard. I would be happy to have a full custom minifig made if anybody could recommend a service.

# Answer
> 3 votes
You might try and post a request on the ALPS Decal Yahoo group. This is an e-mail group that discusses making water slide decals using the ALPS printer. There are members of the group that do have businesses that produce decals. I don't know how much people charge for custom decal sheets. You'll have to ask.

http://groups.yahoo.com/group/alpsdecal/

Most decals that these folks produce use multiple layers of white ink under your actual artwork so that it allows the decal to be placed on a colored brick (not just white). Your artwork also needs to be constructed using multiple layers that are lined up (registered). Because the layers are usually printed in the "spot" printing mode, the actual layer art is black. Think of each layer as a "mask". When they print it, they tell the printer that where ever it sees black, to print say yellow. Yellow is the "spot" color for this layer. You start by printing usually 2 white layers, then spot yellow, cyan, magenta and finally black. The unique feature of the ALPS printer is the capability of printing in overlay mode. What this means is that you tell the printer to print a layer, but don't eject the paper. The printer will rewind the paper back to the beginning and await your next print request. Each print request is a separate layer printed on top of the previous layer(s). This way, the final image is built up layer by layer. On the last print (usually black), you tell it NOT to do overlay and when the layer is finished printing, the printer will eject the paper. This type of printing is a lot of work and can use a lot of ink, especially white ink, which is expensive, but it gives the best results for the average hobbyist.

Like Joshua above noted, you can produce your own decals with a color laser (or inkjet) printer quite easily. You are stuck with a big cutting job if you want to put the decal unto a colored minifig body (using white decal paper). You can use clear decal paper if the artwork is black, because the decal shows fine on white, yellow, tan, red, green, orange, and blue parts. Remember, if you are using inkjet decal paper, you must coat the decal with a clear finish (Krylon), prior to placing in water (to remove the backing) when applying to your minifig, otherwise, your artwork will smudge and wash off your decal.

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Tags: minifigures, stickers
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# Question
Title: What color has been produced in the highest volume?
What color makes up the highest percentage of LEGO elements produced since ABS plastic was introduced in 1963?

# Answer
Black.

Peeron.com has a colour table that lists how many pieces of each colour you would have if you had one of every set in their database.

Obviously their database is not complete, it doesn't relate to when ABS was introduced (but most of the pieces produced in all time will have been since then), and some sets have been produced in higher numbers, so that's not an incredibly reliable figure, but seeing it has more than double the closest rival, I think it's safe to assume that Black's the winnner.

I would think that it is partially due to the fact that technic pins come in black, and there can be hundreds of those in sets.

Incidently, the top 5 are:

1. Black
2. White
3. Old Gray
4. Red
5. Yellow
> 17 votes

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Tags: colour, plastics
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# Question
Title: What are the special features of the Ferrari F1 Racer 1:8 kit?
I found a good price on the Ferrari F1 Racer 1:8 kit. From the picture of the box cover, it would seem that the steering wheel can turn the wheels, but I cannot identify any other moving features.

* Is this a Technic model or just a display model, which happens to use a lot of Technic parts?
* If I am after a model containing many useful Technic parts for use in custom creations, is this a kit to avoid?
* Do many of the side panels appear in other models or were they custom made for this kit and therefore, might have limited value outside of the box design?

# Answer
> 3 votes
I would consider the model as a Technic one (it's built as such), but very poor as far as functions go: steering and the ubiquitous cylinder block, I don't even see any suspension.

You can see the parts included at peeron or bricklink and judge for yourself if the parts interest you or not. As a licensed set, it's likely its price is inflated to cover the license cost, so I'm not sure it's the best parts pack.

The panels are standard Technic panels (with stickers), although LEGO has discontinued them since then in favour or more robust panels which participate to the model structure in their own right.

# Answer
> 5 votes
From the Instructions for 8674-1 - Ferrari F1 Racer 1:8 you can see that the pistons also go up and down and the body can be removed. From the box picture posted the set was part of the LEGO Racers, specifically the Ferrari subtheme.

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Tags: sets
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# Question
Title: Does Toy 'R Us (or more expensive-than-average) retailers have more extra parts than average?
I haven't bought LEGO sets for a while, as my kids are just getting old enough to make the sets, but I am assembling the LOTR sets which I find impossible to resist.

I bought Gandalf Arrives (9469) and Shelob Attacks (9470) from Toys R Us at what seemed like an awful mark-up for them, but I noticed that I got quite a few extra pieces. Then I bought another The Orc Forge (9476) from Walmart and got marginally more than I paid for.

If this is idle speculation, I'll delete the post, but if there's something to it I'd like to know!

# Answer
I will start by saying I do not own any of the LOTR sets. But, Bricklink has inventories of many sets including any extra pieces that were included with the set. You do not mention which specific sets you own, but here is a link to the 9474 The Battle Of Helm's Deep inventory on Bricklink. It lists a total quantity of 6 extra pieces (5 unique). You could compare the extra pieces in your sets to those listed on the Bricklink inventories and if you do indeed have more, then there may be something to it. Unfortunately Bricklink does not list where the set being inventoried was purchased from so without input from some other bricks members who actually own the sets then we can't know for sure.
> 9 votes

# Answer
The number of parts shown on the box of the LEGO set indicate how many parts are included without the spare parts. Spare parts tend to be added for the smallest pieces of a set that can be lost easily.

Spare parts *tend to be* fairly consistent between identical sets regardless of where they are sold and sets with a greater amount of parts will generally have more spare parts.

I wrote to LEGO customer services, here is a quote from their response.

> When it comes to spare parts, it is random what pieces are included in which sets. We always want to make sure our fans have a little extra to go with their awesome imaginations.
>
> *LEGO Direct Consumer Services*
> 10 votes

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Tags: shopping, manufacturing
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# Question
Title: What does imprinted information inside bricks mean?
I just randomly checked the imprinted information inside some of the bricks in my Lego sets and found that it varied.

I found several different types of information:

* Most pieces have Lego copyright notice ie. (c) LEGO, but many others don't have
* Most pieces have two numbers are thin and italic, but some others are in bigger font.
* In some pieces, there is a third number instead of LEGO copyright notice.

How does this information vary by year/set/produced country?

# Answer
> 13 votes
Most elements will have their official "Design ID" imprinted on them - this is typically the longer number, and can usually be used on the Pick a Brick site or sites such as BrickLink and Peeron to track down additional bricks. Note that this is different to the "Element ID" that is printed in the instruction part inventories which has the colour encoded with it.

I've got the following three elements in front of me at the moment:

The 6x2 plate \[part:3795:6\] has the following:

* *© LEGO* (highlighted in red)
* 03795 - This is the padded Design ID (highlighted in blue)
* 10 049 (highlighted in yellow)

The 4x1 tile \[part:2431:6\] has the following:

* *© LEGO* (red)
* 2431 - This is the Design ID (blue)
* 15-10 (yellow) - 3 others in the same set had different numbers

The Plant Leaves 4x3 \[part:2423:2\] has the following:

* *© LEGO Group* (red)
* 2423 - This is the Design ID (blue)
* 6•02 (yellow) - another one of these in the same set had the same number.

I believe the numbers highlighted in yellow are mould numbers - so the factories can track down imperfections with old moulds or similar.

Looking at an element that I have in rather large quantities now, the Tile 4 x 3 with 4 Studs in Centre \[part:88646:0\] taking four at random they all have:

* *© 2009 The LEGO Group*
* 88646

But then each one has a different mould ID: `01-B04`, `04-B04`, `10-B02`, `08-B08`

With regards to the copyright statement - as you can see across from these examples, they use different versions depending on the space available. I guess they feel that having the part and mould ids are slightly more important than their copyright statement for tracking purposes.

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Tags: piece-information
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# Question
Title: How can I add additional detail to large walls?
I've seen some rather impressive castle builds over the years, and with the release of Helm's Deep I'm clearly going to be building a few myself now.

As this set uses the LEGO sticker sheet to add some detail to otherwise flat walls, I'd like to modify these builds to include some better "brick based" details - but I'm not sure where to start.

Ideally I'd like to create some additional depth, and perhaps add some vines or ivy up the walls, that sort of thing.

Unlike previous questions I have a fair selection of bricks, including various SNOT elements.

# Answer
Classic-Castle.com has a guide for making castle walls more visually appealing. Key points:

* Different colours, shades and textures of bricks add subtle imperfections.
* Break up the monotony with windows, doors, arrow slits, balconies and other structural features.
* Use timber (brown/tan) as well as stone (grey) bricks and try out adding different materials.
> 12 votes

# Answer
I don't build castles in general. But I do build Churches. For me I go very simple when it comes to breaking up the walls. I use an extreme amount of windows. Other shades of bricks. Often will use another color to add details or designs.
> 3 votes

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Tags: building, castle
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# Question
Title: Good LEGO CAD Design Software with Technic elements and animation
I'm taking computer engineering in Gr. 11 right now and our final project is to create a robot with the first version of Mindstorms. My partner and I are making a sumo robot for the class competition. We don't have the required parts at home such as gears and technic pieces and we're not allowed to take home the pieces.

We're using LEGO RCX 1.0 with 2.0 firmware and mostly technic pieces. Is there some type of CAD software that lets me test to see if the gears do what I want it to? I know LDD does this to an extent but they don't have the RCX 1.0 pieces, and placement of pieces is frustrating.

Also, I have the .dat files for LDraw, is there a way to import those parts into LDD?

# Answer
> 8 votes
Take a look at SR 3D Builder. I have not used this software myself but it looks like it may do what you need. It's free (for non-commercial use) and you can import your LDraw files.

Here is a link to some videos on YouTube

See below for the features list (taken from the website)

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

# Answer
> 4 votes
Edit to update: It looks like the NXT version of RDS only really supports the "Tribot", and has partial support for the "ShooterBot", but does not have a simulation of it.

---

I know the original Microsoft Robotics Studio supported building robots using the RCX bricks - although the latest version has been upgraded to NXT and it has simulation tools too for testing your robots prior to building and deploying your code.

As the core components should be the same (gears, beams, etc.) you should be able to get a reasonable way through testing even if the final code has to be written elsewhere.

I know some people have had success upgrading the RCX samples to newer versions of RS, but I'm not sure if anyone's tried it with 4.

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Tags: building, technic, mindstorms, software, rcx
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# Question
Title: Can you program an RCX using the Mindstorms NXT 2.0 software?
I was asked to teach a robotics class and found several RCX bricks in storage. Can I use these bricks with the Mindstorms NXT 2.0 software? If not, what would be the software I would need to use the RCX bricks?

# Answer
> 5 votes
No, the standard NXT-G software provided by LEGO will not allow you to program a RCX brick.

Outside of official software, your best bet is probably to use NQC which is C-like; there's also NXC for the NXT which is similar.

There are a lot of others which have been discussed in the following questions: Is there any other way to program the Lego Mindstorms NXT other than the provided software? and Can I write programs for the LEGO RCX 2.0 in Java/C++?.

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Tags: nxt, mindstorms, programming, rcx
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# Question
Title: Which type of LEGO bricks would be compatible with the Mega Bloks Blind Bag Figures?
My husband collects the Marvel figures which come in the Mega Bloks blind bags. His birthday is coming up and I'd like to build him a display for his Marvel figures. I'd strongly prefer to use LEGO in order to build this display. I've read that certain types of Mega Bloks are compatible with certain types of LEGO bricks. (I will most likely have to purchase online so I won't be able to compare size in person before purchasing.)

How can I make sure that the type of LEGO I am buying will fit the foot holes of the Mega Bloks Marvel figures?

# Answer
> 4 votes
Mega blocks can stand on any Lego plate just as good as Lego figures. This is demonstrated in this battle scene between Lego and Mega Blocks figures:

mega bloks halo vs. lego star wars clones
<sup> Before you play this, I advice you to turn down the sound a bit... </sup>

# Answer
> 2 votes
You could use any LEGO plates with the mega bloks figures. In the blind packs they stay on the mega bloks doublebricks, that are fully compatible with LEGO doublebricks. So you could take any set pack as you want. (some time ago i have used lego collectable minifigures stand with megabloks figures, it was usable, but i think they weren't standing too tight in there).

# Answer
> 1 votes
If you're just looking for some LEGO Bricks to build up a scene, then any of the standard LEGO sets or boxes of bricks would fit the figures - certainly the holes in the feet will fit the LEGO studs quite nicely, and the feet are spaced correctly to fit.

You could also take a look at the Marvel Super Hero range that LEGO offer which include a rather large diorama set 6868 Hulk's Helicarrier Breakout.

Note that the larger figures on the LEGO Shop page aren't compatible with the Megabloks figures, as they're over 7 inches tall.

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Tags: building, compatibility, clone-brands
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# Question
Title: What LEGO wheels would look like the three types used on the JPL Mars Rovers?
I would like to build the three types of JPL Mars rovers (Sojourner, MER and MSL) with the right size ratio relative to each other. For that, finding the right wheels would be the hardest thing. I can build the rest of the robots as long as I know the wheels will have the right look.

Here's a pictures of the three wheel types:

Important Notes:

* The overall size doesn't have to be at the scale of the minifigures. Even though this would be really cool, it would turn the Sojourner project into a micro build. This would be much harder.
* The look of the wheel hubs is not relevant. What is important is the look/ratio of the tire's outside dimensions. Note that Sojourner's wheel (the small one) has a flat rolling surface while the others two are rounded.

**Edit:** The medium wheel is (appropriately) **1.8x** the size of the small wheel while the big wheel is (appropriately) **1.7x** the size of the medium wheel.

# Answer
> 6 votes
Here's what found after playing with all kinds of combinations. With this the three rovers will be at the same scale (about 1:5.8). This scale is small enough that the big rover (MSL) would not be a monster to build.

The ratio is almost spot on and the only main problem is that the MSL wheels (the big ones) will have those big cleats.

On the positive side, they all have the right shape. Only the medium wheels have that bulgy look while the other two have a flatter driving surface.

Here are the parts numbers:

* Sojourner (small): **6014ac01**
* MER (medium): **6580c01**
* MSL (big): **64711**

# Answer
> 9 votes
The first that came to my mind (for the MER-wheels) is the Wheel 70 x 28 mm Futuristic, with Black Tire:

# Answer
> 5 votes
It would probably be easiest to work out the which piece should be used for the biggest wheel.

The largest wheel I could find came in the 8420 Technic model. Two of which can be used in tandem to increase the surface area of the wheel:

**Wheel Technic Street Bike (8420)**

The medium wheel could be a rather blocky **Wheel 20 x 30 Technic**, the **68.8 x 24** or the incredibly useful **30.4mm D. x 20mm** (four of which come with the NXT 2.0.)

The smallest wheel can be any of the tyres from a medium sized LEGO CITY vehicle such as the Prisoner Transport set.

I'd recommend having a look at Bricklinks database of wheel pieces to see what else is on offer.

# Answer
> 5 votes
You might also be able to make wheels out of parts, such as a circle of hinges with brackets and cheese slopes. I'm sure there are better ways, but that was the first that came to mind.

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Tags: building, wheel, scale
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# Question
Title: How to convert new 4x4 crawler to tracks?
With the new 9398 4x4 crawler coming out what would need to be done to convert it to a track based system that looks similar in style to the ones sold by Mattracks?

On a related point what would make a good basis for making a Lego Technic model of the tracked buggies used in Prometheus that use similar 'track wheels'?

# Answer
I started with something based around the tracks that came with the original LEGO Mindstorm's kit: 680 Technic Tread:

I then build a rather more bulky than I'd have liked set of beams around it - I think if I'd have really dug out my Technic elements I'd have had more success making it look closer to the mattracks options:

Here's the very bulky rear - this would obviously want to be pared down somewhat, and you might want to either power the top wheel, or both the bottom ones:

Here's the rear with the beams removed:

You would need to have the driving axle on a universal joint to allow cornering, and would want to mount the whole thing on the mounts for steering.

I think it would be better if I'd had more of the newer Technic beams (the ones without the studs - I could have then connected them with two coat-hanger pieces and have another one vertically to the top.
> 6 votes

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Tags: technic, customization
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# Question
Title: What kind of yellow is used for a typical minifigure?
I've done some research and found a basic LEGO basic colour pallet. I recognise the yellow used for yellow bricks (24, Bright Yellow, #fec400) but it doesn't seem to match the colour for minifigures which are slightly less orange.

# Answer
> 10 votes
I believe it is supposed to be 24 Bright Yellow, however I know there were some complaints a last year or so regarding the collectable Minifigures and others that were made in China not having the same hue as "regular" minifigures - and now that some of the licensed products are also being made there, this difference will become more common.

These figures are apparently not made from ABS but a cheaper plastic, which is what causes the difference in colour.

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Tags: minifigures, colour
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# Question
Title: What are some free kid-friendly tutorials to get started with Mindstorms Nxt 2.0?
My daughter (10) got the NXT 2.0 for christmas. It doesn't really come with any tutorial. I'm looking for something she can follow which will teach her to use each of the sensors and slightly more advanced topics like executing a 90 degree turn (how to find exactly the # of rotations of each wheel to do that for your particular turning radius).

Can be any free resource (YouTube videos, etc.)

# Answer
You can find some free instructions at http://www.nxtprograms.com/ and at http://thenxtstep.blogspot.com/p/building-instructions.html. But I am not sure if you can say they are kid-friendly.

And here is another one: http://legoengineering.com/curriculum-submenuteachingresources-142.html
> 5 votes

# Answer
One of the most heavily used is mine at NXT Tutorial.
> 2 votes

# Answer
There's a NXT User Guide available from LEGO education, but it deosn't seem to conatin much in the way of tutorials.

While these are not free resources, you (or other people asking themselves that kind of question) could also have a look at various printed books on the subject.

In particular, "LEGO MINDSTORMS NXT: The Mayan Adventure (Technology in Action)" is very accessible, and you can see a few sample chapters in the first link. There is a forum devoted to it, apparently. Interestingly, LEGO education sells a parts pack for it, which should say something about the quality fo the book.
> 0 votes

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Tags: nxt, mindstorms
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title: LEGO Scalextric?

text:
# Question
Title: LEGO Scalextric?
I have a couple of these car parts in my collection but cannot find anything about them. They are copyright 2003 and show a number 3213 on the back axle.

Interesting is that they have 3 electrical connectors on the underside that suggest it gets power from a track of sorts. Something like LEGO scalextric.

Can anyone shed some light on what this is and how it worked and was controlled?

# Answer
> 7 votes
Sounds like this:

Which can be found in set 8364 only. It's recharged by pushing the car on a charging track piece, itself powered by batteries:

.

Not particularly good, but the sheer number of track parts in the set makes it interesting to buy for some people.

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Tags: part-identification, electronics
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# Question
Title: Is it possible to build a full-size house with Lego bricks?
I want to build something big.

Should* I build a complete house (interior and everything) with lego bricks?

* By "should" I mean, will it be safe? How big can I go? How much do you think it will cost?

# Answer
James May built a full-sized LEGO house for his TV show James May's Toy Stories on the BBC back in 2009 using around 3,500,000 bricks. Whether you'd actually want to do this yourself...

During the episode they spent some time with engineering students working out the most load bearing configurations of bricks especially for the upper floor, as well as working on the general structure.

To get around the insurance requirements, in the end they resorted to building the house around a wooden frame including floors - and although they did continue working on the beams, and James did stand (rather nervously) on the final designs, they don't appear to have been released.

With regards to the rest of the house (i.e. fixtures and fittings) there were some issues as I recall:

* Comfort - obviously lying or sitting on LEGO bricks without any covering is uncomfortable.
* Water Proofing - at one point in the show James shares a LEGO "glass" of wine with Oz Clarke - only to have most of the wine leak out of the glass. Without some sort of sealant, or multiple offset layers the gaps between the bricks aren't water-tight.
* Clutch Power - LEGO bricks are held together by friction (Technic pins not withstanding), and tend to break apart under incorrectly placed loads quite easily. This may be an issue when it comes to chairs, doors, etc.

Wikipedia article
Show on YouTube (part 1/5)
> 21 votes

# Answer
If you want to know how many bricks you'd need, there is some site to help you calculate it.
> 2 votes

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Tags: building, safety
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# Question
Title: Does the PF Servo motor return to center?
Does the PF Servo motor, which was introduced in the 9398: 4x4 Crawler model, have return to center feature?

# Answer
> 5 votes
Here is another video from Sariel which shows that it returns to center: http://www.youtube.com/watch?v=T\_Gvuzsngg8

# Answer
> 4 votes
Yes it does, see http://technicbricks.blogspot.fr/2012/06/pf-servo-in-action.html

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Tags: power-functions, motor
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# Question
Title: What minifig configuration has been included in the most sets?
Which minifigure configuration has been included in the most sets? I'm looking for the color of the head, arms, hands, legs, pelvis, and torso as well as the facial expression and any headgear. Please include an image of this minifigure doppleganger.

# Answer
So far, the best I can think of is the red classic space guy which appeared in 46 sets.

Considering minifigs were less specialized back then, I bet the winner is in that time period anyway, and the fact that spacemen wore an uniform makes me think there is no other minifig apperaing in 46 sets. Even the basic city worker only reaches a pale 21 sets.
> 10 votes

# Answer
The Skeleton with Basic Skull appears in 42 sets. If you include the sets that have the same figure only with different headgear, the number of sets is 56.
> 6 votes

# Answer
If you had one of every set in peeron's database:

Torso: 973 \- A plain torso - Black

Head: 3626ap01 \- Normal plain smile - Yellow

Legs: 970c00 \- Plain legs - Black

Their database is not complete, I haven't been able to find data for colour of hands or arms, and this is for each peice individually, not the minifigure as a whole, but I think it's the best that can be done.

This image isn't very good quality, but I had a go in Photoshop...
> 1 votes

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Tags: minifigures, history
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title: Why did they cancel Mars Mission?

text:
# Question
Title: Why did they cancel Mars Mission?
Does anybody know why LEGO canceled the Mars Mission line? It was so good and I almost had everything! I don't wanna buy off eBay because that can get expensive. I liked it a lot!

# Answer
> 11 votes
In this forum, I found a reply from the Lego Group in response to an email asking a similar question but related to the Mars Mission *games*:

> Thank you for contacting us and for your interest in LEGO® brand products.
>
> Unfortunately, because The LEGO Mars Mission line you inquired about has been discontinued from our current product line, we do not intend to create new games based on this theme. Each year, several items are discontinued and new ones added. By doing this, we provide a product line with more variety and continuing challenges to our LEGO builders. You may like a game based on our Space Police theme called Galactic Pursuit, http://spacepolice.lego.com/en-US/games/default.aspx. You may also like a multiplayer interactive game named LEGO Universe that will be released this upcoming summer. To preview this new game, you can visit LEGOUniverse.com. I hope this information helps!
>
> Thank you again for contacting us.
>
> --LEGO Direct Consumer Services

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Tags: sets, theme, space
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# Question
Title: What disinfectant can I use on used LEGO parts?
> **Possible Duplicate:**
> LEGO cleaning techniques and tools

I usually purchase LEGO parts at yard sales and the like and would like to disinfect them before using them. Can I use any spray disinfectant on parts without ruining them? Should I be wary of any disinfectants that would cause LEGO parts to fade in color?

# Answer
In the past I have used dish soap and a basin and just soaked them in hot soapy water for a while. I then learned that MegaBlocks float while LEGO sink.
> 2 votes

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Tags: cleaning
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# Question
Title: Is it possible to connect an RCX to an iOS device?
I have an RCX and want to know if it's possible to connect it to an iOS device. If this is possible, how do I do it?

# Answer
Communication with the RCX Brick was via the Infra Red tower (or IR Remote Control) which connected to the computer with either a serial or USB cable.

As neither iPhone nor iPad have an IR port, there's no way to connect directly between the two.

You might be able to do something with a docked iOs device, but that strikes me as somewhat pointless.
> 5 votes

# Answer
There are ipad adaptors for iPad, iPhone. Some connect to the data port, but others connect to the headphone jack, so are eminiently programmable - you presumably just need audio samples. Alex
> 2 votes

# Answer
You could do it using a computer as an intermediate. Basically, you have a wireless connection between your iPhone and your computer, then the IR link between the computer and the RCX. It would be technically challenging but not impossible. The IR tower uses a serial port and the protocol is detailed here http://legolab.daimi.au.dk/CSaEA/RCX/Manual.dir/RCXManual.html. The connection between the computer and the mobile device could simply be achieved via wireless connection using TCP sockets and wouldn't have to follow any very specific protocol at all. All of this could be achieved with any number of programming languages, but Python and Visual Basic would likely be the easiest. I could help you write the software to do this if you are very determined, but I only have experience with Windows, so the computer itself couldn't be a Mac.
> 1 votes

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Tags: rcx, remote-control
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# Question
Title: How much does a life sized LEGO person sculpture weigh?
Generally, how many pounds of LEGO would it take to make a life sized person sculpture? Do they weigh anywhere near the same as the real person they are modeled after?

# Answer
The image posted in your question shows the Lego brick artist Nathan Sawaya.

On his website, he states:

> A life-size human form sculpture typically has 15,000-25,000 bricks.

So, lets use 20,000 for our calculations.

Next, how much does a brick weigh, well of course it depends on the type of brick, but if we take the common 2 x 4 Brick , Bricklink tells us that one 2 x 4 Brick weighs 2.32g.

```
20,000 x 2.32 = 46,400g
= 46.4Kg
= 102.3Lb
= 7.3 Stone

```

So one could say they are **very roughly** equivalent in weight.

But if anything, the Lego versions are likely lighter than their human twins. This is especially true if we consider that many of the bricks will be smaller than the 2 x 4 Brick we used in the rough calculation above. For example, according to Bricklink, the 2 x 3 Brick weighs 1.92g and the 2 x 2 Brick weighs 1.21g.
> 10 votes

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Tags: building
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# Question
Title: Is it possible to obtain a replacement part for a collectible minifigure?
My son's latest collectible minifigure purchase was missing its legs. Is it possible to get a replacement set of legs?

# Answer
> 10 votes
In short, yes it is possible.

The best place to find replacement parts is Bricklink.com.

You don't mention which minifgure is missing its leg, but for example, here is a link to the 'Hips and Legs with Studded Belt and Safety Pins Pattern' of the Series 4 minifg 'Punk Rocker'.

To find the required part for your minifig, a good starting point would be to look thorough the Collectible Minifigures Catalog Gallery on Bricklink and go from there.

As for cost, it varies greatly on based on rarity and desirability of the part you are looking for.

# Answer
> 13 votes
LEGO will replace a part for free on their website, providing it was missing from purchase. Sadly replacement parts aren't available for Collectible Minifigures, but you can contact them to let them know.

Ensure the Minifigure packet has been fully emptied, it's quite easy to lose parts when you open the packet.

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Tags: minifigures, replacement-parts, collectable-minifigures
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# Question
Title: How can I upgrade the firmware of an RCX 1.0 to an RCX 2.0?
I have an RCX 1.0 set from 1998 and I would like to upgrade the RCX 1.0 to RCX 2.0. Can this be done? Exactly how would I obtain a firmware file and load it? I do have access to the Bricxx Command Center, if required.

# Answer
> 8 votes
The hardware of RCX 2.0 is identical to 1.5, and the only difference between these two and version 1.0 is the charging port which had been removed. So they're compatible and you can indeed use a newer firmware on an older brick.

You'll need the Mindstorms 2.5 SDK, which contains the latest official firmware. It's probably not on the LEGO site any more, but Philo has saved it for posterity on his site.

You may also want to use a compatible, but faster, firwmare from Dick Swan, you'll find it archived here.

As for uploading it to the RCX brick, I think there's indeed an option for it in BrickCC but I'm not too sure where, so I can't help much there. It's probably in the documentation somewhere.

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Tags: rcx
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# Question
Title: How can I convert an image's pixels to actual LEGO colors?
The LEGO Group released a few "mosaic" sets a while back, which came with clear baseplates and a bunch of 1x1 bricks. I have been wondering recently if it is possible to use an image as a reference when building one of these.

Unfortunately, this is hard because digital images can have a lot more colors than there are actual LEGO colors.

I am not interested in anything more than 1x1 bricks on a baseplate, regardless of the fact that the image has some other bricks added onto those 1x1s. The scenes which I would be interested in building would effectively be two-dimensional.

Is there perhaps a way (besides approximating) to change the pixels of an image into actual LEGO colors? Is there perhaps some type of web-application for this?

Related: How many different colours of LEGO bricks are there?

# Answer
You can use GIMP for this. First you need to scale the image to the size you want. (If you want to stack bricks on top of each other instead of a baseplate, use a different y-scaling to correspond the bricks height.)

Now create a palette by going to the Palette tab and click the "New palette" icon.

In this add the bricks colors you want. You can find the colors RGB values to a brick color here: http://www.peeron.com/cgi-bin/invcgis/colorguide.cgi

Now convert into these colors by going to "Image-\>Mode-\>Indexed...". (If indexed is already selected, select RGB first and then click Indexed.) A "Convert Image to Indexed Colors" dialog box should appear.

Select "Use custom palette" and select the palette you just created.

Click "Convert" to get your result. If you are not quite satisfied, click undo and try to change/add some colors in your custom palette and convert again.
> 11 votes

# Answer
You can also use the web-based Mosaic Maker.
> 5 votes

# Answer
Similar to 'Mosaic Maker' suggested by @Conrado PLG , there is 'Bricksaic' from Bong 69 Productions.

From their website:

> A program used to make Lego Mosaics. You choose the image, the stud width and the type of bricks to use and you instantly have an LDraw file to make the mosaic from.

I have used the software myself and found it to be complete and functional with lots of nice options. It seems to do exactly what you are asking for by taking a digital image, and creating a 'LEGO map' of parts using only the colours that you specify. (The choice of colours being only actual LEGO colours).

Feature list (from their website):

* Choose the image
* Choose the stud width of the mosaic
* Choose from 7 different Dithering routines
* Use up to 41 colors in the color palette
* Makes an LDraw file
* Prints a color map
* Loads and Ldraw file made with Bricksaic
* Choose to use plates or bricks and studs up or studs out from these selections: 1x Plates - studs up 2x Plates - studs up (2 studs thick) 1x Bricks - studs up 2x Bricks - studs up (2 studs thick) 1x Plates - studs out 2x Plates - studs out 1x Bricks - studs out 2x Bricks - studs out
> 3 votes

# Answer
On the Mac you can use an app called Digital ColorMeter, whcih is built into the Mac by default. The app can be used to parse out colors on a screen base on their R G B ratings, so you can just hover the mouse over a picture of a lego brick for a semi-accurate rating if the photo is good. If you have a program that can generate colors based on the R G B ratings of colors you could use the color, or you could install Hex Color Picker and enter the HTML color-codes into the Mac color picker if you can get the color codes with a certain program.

Hope this helped. :)
> 2 votes

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Tags: software, colour, mosaic
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# Question
Title: Is there any application to keep an inventory of owned sets and pieces?
I'm looking for a desktop application that keeps track of sets and pieces owned. Ideally something that would look up LEGO databases such as Peeron or others in order to add the pieces in a set automatically once on is added. Similarly, said app could tell you which sets you could build with your current pieces, much like Rebrickable.com, as mentioned in a previous question.

# Answer
I know of no desktop applications that have functionality like Rebrickable, but an API has recently been released which would enable any applications to integrate with the site and display this kind of information. I know of one such application currently being developed but not ready for release yet.

disclaimer: I created Rebrickable.
> 18 votes

# Answer
There is a tool called BrickStore that might do what you want. It is tightly connected to BrickLink.
> 6 votes

# Answer
As far as a desktop app for inventorying pieces, I personally use Brickstore as suggested by @Superkalle. Although I use it primarily for preparing Bricklink orders rather than a catalogue of my spare parts and/or sets.

Should you be interested in an alternative that may be more suited to keeping track of pieces you own, there is 'Parts Catalog' from Bong 69 Productions.

From their website:

> Parts Catalog is a program used to inventory your collection of Lego parts. The main goal is to be able to check 2 list to see which parts are missing. To build your list you could just download certified list of Lego sets and Combine the list. Then add any single parts that may not be from a set.

Features list (from their website):

* Make and save your own inventory list
* Combine and save inventory list
* Sort parts by Part Number, Description, Color, or Count
* View an image of the part (if an image is available)
* Compare 2 list to see which parts are missing.
* Compare 2 list to see which parts you have.
* Make an inventory list from Ldraw dat files.
* Open/Save a list in the Peeron (.prn) format
* Open/Save a list in the CSV (.csv) format
* Open/Save a list in the XLS (.xls) format
* Open a list in the Bricklink XML (.xml) format
* Open/Save a list in the Bricklink (.blk) format
* Open a .htm inventory file saved from the peeron site.
* Render images using LDraw dat files
* Zoom and Rotate images that are rendered with LDraw dat files
* Download inventories from peeron
* Make labels from LDraw files
> 1 votes

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Tags: storage, tools, software
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# Question
Title: What are Good LEGO (or similiar) sets to play-prototype machines working with fluids?
I want to play around with fluid engines.

I'm aware that LEGO is sometimes used in labs for prototyping kinematic components, are there successful examples of operating with fluids?

Have pistons, pipes or other conduits, valves and maybe turbines been built with LEGO?

With what components?

# Answer
> 15 votes
There are a number of Lego Pneumatic sets with airtight tubes, valves and switches which could be put into use with fluids. One is 9641, Pneumatics Add-On Set.

Bear in mind that the pneumatics sets can command a much higer price than those sets with a similar number of parts, and buying individual pieces can also get expensive. Have a look at BrickLink to see what parts are avalible.

There is also a Simple & Powered machines set which comes with sails that could be used as a wind turbine, or a basic pump, but if you wanted to use steam or liquids with Lego you would have to be very careful.

A company called LPE Power has made some very detailed and very powerful pnuematic engines however I doubt they would work with water.

# Answer
> 6 votes
The Lego pneumatic valves are not great for (liquid) fluid experiments as the valves dissipate the return path to atmosphere, so they p\*ss water out. And the pneumatic hand pump spring and metal core of the regular pistons rusts in a few days. It's about 15 years since I learn't this :-)

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Tags: technic, water
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# Question
Title: Can 10153 9V train motor be powered by the Power Functions Battery pack?
I am currently making the switch to Power Functions with my Lego Train collection and am wondering if I can power the old 9v motors that I used with the metal rails, with a battery box from the power functions line? I tested it and it does run but I'm concerned that it may burn out or not be safe... Any advice?

# Answer
> 8 votes
In short, yes it's perfectly safe to run your old 9v motors from your Power Functions battery box.

This excellent online reference has a lot of information on various LEGO motors. Both the old 9v train motor and the Power Functions train motor are listed.

The information on the site shows that the characteristics of the two motors are very similar with the old 9v motor drawing 0.38A @ 9V and the Power Functions motor drawing 0.38A @ 9V.

The old 9v motor does draw slightly more current, (0.40A), @ 4.5V compared to 0.36A @ 4.5V for the PF motor, but this difference is negligible and will not translate into any damage to your motor or battery box.

---

Also there is official confirmation from LEGO via their Power Functions FAQ

> Can I use Power Functions elements with my old 9V elements?
>
> Yes, with 8886 Power Functions Extension Wire or 8871 Power Functions Extension Wire 20” you can use most of the 9V elements with Power Functions.

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Tags: power-functions, compatibility, 9v, motor, battery
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title: how to build a diorama

text:
# Question
Title: how to build a diorama
I have almost all the items from the Lego Castle Fantasy set, and I would like to build a nice full Lego diorama, but I have no clue on where to start. Do you know if there is a tutorial on how to plan the diorama and how to build the terrain to make it solid enough to sustain the items and movements?

# Answer
If you have access to some Duplo elements, these make good "bulking" blocks for larger terrain sections - as the 2x2 and larger bricks fit over the top of the duplo studs you can build a fairly stable base using those, and then work on the sides and top with System elements as needed.

Otherwise it comes down to sensible building techniques such as starting with larger blocks, overlapping them correctly so that each layer provides support to the ones around it.

There's a good answer on how to build a large structure for transport, which talks about using Technic bricks and pins to connect the sections together, as well as the answer on connecting levels of a multi-story building using tiles and jumpers or 1x1 plates to provide some grip while still enabling access inside.
> 5 votes

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Tags: building, sets, castle
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# Question
Title: What LEGO cases are available for phones?
I would love to have a LEGO case for my HTC Desire that have LEGO compatible knobs so I can attach LEGO brick on it. Be free to post answers for LEGO case that is for other phones as well, as this is probably something that is interesting for everyone - not only those with HTC Desire...

<sub> Someone has taken the drastic move to make their own... I don't want to sacrifice LEGO bricks like that... </sub>

# Answer
> 7 votes
I am not sure such a case exists for the HTC Desire. All of the LEGO *style* phone accessories I have seen in the past have been for the iphone.

A bit of searching turned up these items:

What appears to be a case with LEGO compatible studs (for iphone)

Check out this page for other LEGO relates accessories and a picture of the above case in use with actual LEGO built onto it (near the bottom of the page).

There is also a TinkerBrick LEGO iPod/iPhone 3 case which has studs on the front and sockets on the back. There are taking Votes for the next supported phone on their site.

There is a mock LEGO silicone iphone case available here. The two pieces can be attached in different positions.

To wander off topic slightly, there are other 'phone related' LEGO *style* accessories available that are compatible with most phones:

Dock cover available here.

LEGO brick earphones available here.

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Tags: accessories
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# Question
Title: I found this piece in a yard sale grab bag. What other elements do I need to make it work?
I found this piece in a yard sale grab bag. What element(s) do I need to make this element function as it was originally intended?

# Answer
Technic Turntable Large Type 1 Base (2856).

It's a Turntable Large Type 1 Top (2855) which is part of Technic Turntable Large Type 1, Complete Assembly (2856c01).
> 9 votes

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Tags: piece-usage
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# Question
Title: Instructions on small car, came with Technic Race Car, circa 1986
When I was about 10 (so, about 1986), I had a Technic race car (formula-1 like), and the instructions had an alternate thing you could make. It was just a small car, with rack and pinion steering.

I must have made it 100s of times, and would like to find the instructions again, to make it now. I don't have the race car kit, but I probably do have enough LEGO to make the smaller car.

I've tried to work out what the original kit was, but can't locate it.

Can anyone point me in the right direction?

Thanks, Brock

# Answer
Your best bet is probably to browse the list of Technic sets on Brickset (sort by year of release, ascending).

There aren't that many before 1990 so it should be easy to find, one which sounds a bit like what you describe is 8865 Test Car from 1988.
> 6 votes

# Answer
the two sets that come into my mind when reading the description are a Go-Kart (8842) and a Roadster (8832) \- maybe it's one of those (would be a lot easier if you remember some additional details - the main color, for example).
> 5 votes

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

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

I have a few pieces, however, that have another distinct style:

This is also a thinner style, but is not italic, like the modern style. The pieces I have seen it on are white plates with the modern underside - not the old waffle type.

I want to know roughly when this logo was used - It would appear to be later than the old style logo, but concurrent with the modern logo. I am also wondering how long it was in use, and whether bricks with this style logo were produced in a specific place; i.e. whether they are Samsonite from the US or Canada, or distinct to one of the European manufacturing locations.

*Additional Information*

The pieces I have that display this logo are white 6x8 plates with Pat Pend on the underside in block caps. This style plate first appeared in sets in 1961, and I believe by 1976 most of the Pat Pend molds were either replaced or had the words obscured. That narrows the date range down somewhat for this particular piece.

If anyone has examples of other pieces with this style logo, especially if they are known to come from a certain set, that would be helpful in answering this question.

# Answer
NOTE: from 1949 to 1954 "LEGO" was printed INSIDE the brick.

LEGO appeared on the studs for the first time in the late 1954, then it was re-designed a lot during the years, becoming the stud we all know.

The not-italic stud of the photo was produced between 1960 and 1963. You can easily exclude 1963+ noticing that it's not the same exact plastic of the modern bricks (ABS was adopted in 1963).

Hope this helps. P.S. I'm a huge LEGO collector and I'll be glad to share my expertise here and learn from other passionate people.
> 5 votes

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Tags: history, manufacturing
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