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What is the best-practice for circular lego staircase construction?
Aside from using the grey key-hole shapes, I'm looking for a Lego-standard or best-practice method for building a circular Lego staircase?
Requirements:
6-8 studs "wide" (from the center to outer edge)
Sturdy, play-able construction
Connects at either 90 or 180 degrees to a floor.

There's a brick-built spiral staircase in the Pet Shop:

That's definitely the most common way to do it. You just build up around a central point. This can be expanded to use longer or wider steps:

http://www.mocpages.com/moc.php/267772
You can also use 2x2 turntables if you need more strength and/or larger stairs:

http://www.popscreen.com/v/6UIWz/Tutorial-Lego-Spiral-Staircase

In the last case, since the rotation point is centered on the plate, it means you can attach steps one to another easily, either at the end (replace the 1x2 tile by a 1x1 tile and a 1x1 plate on which the next step is attached) or closer to the center if you prefer. Note however that this fixes the angles and that it probably won't be exact at the end of the stairs.


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Why does LEGO state the number of parts on US boxes, but not in Europe?
I was reading Huw Millington's review of set 70700 Space Swarmer on brickset, in which he states:

The box is almost square and this being from the USA, like all US boxes but unlike European ones, it states the number of pieces on the front. I'm guessing that it's some sort of requirement to do so in the USA, but I wonder why LEGO don't print it on European boxes. It's useful information for the consumer, after all.

Which I think is a very valid question.
Are there indeed such requirements in the USA? Are there other countries with similar requirements?
And I guess this will be harder to answer, but why doesn't LEGO just state it on all boxes anyway?

I wonder how this US requirement to accurately state the number of pieces sits with this statement from LEGO customer services: "When it comes to spare parts, it is random what pieces are included in which sets", relating to the spare parts included with each set. They must mean the parts are random, but the count is consistent. From this post by @Ambo100 in another LEGO Answers question.

Which if you ask me is a bit weird considering the extra parts seem to be extremely consistent

There is indeed a requirement that packaged products sold in the US must indicate the weight, volume or quantity plainly on the package. This is regulated by the FTC, which says in its requirements,

The net quantity of contents (in terms of weight or mass, measure, or
  numerical count) shall be separately and accurately stated...

Canada has a similar law that says the net quantity of packaged products must be on the label.
The European Union's product labeling requirements do not appear to make the quantity a mandatory part of the product label. I do not think it actually prohibits putting the number of pieces on the packages, so it may not explain why The LEGO Company leaves that information off their European packages.

Thanks, that's at least one important part of the question answered - and I fear the rest won't be anyway.

Being an EU-based company, TLG design may well design their boxes for local EU-based markets first - where there is no need for a piece count - and then adjust the designs for other markets later. This is pure speculation, of course.

We can only guess, but in my experience dealing with other large companies, the philosophy seems to be not to exceed the legal requirements. They are advised by their legal departments to do what the law requires but no more than that.

I suspect they feel that the part count might make people think it's not good value, so they don't have it in markets where it's not required.

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Why do official Lego sets sometimes use 1 large part when several would work just as well?
One of the things that makes Lego so great is the ability to rebuild sets into something new and different. However, I know that sometimes TLG uses large pieces to lower costs and/or build complexity. Some examples:

54092cx1 - Plane nose
30295 - Large car base
6082 - BURP

It seems to me that some part choices are quite strange. For example, 7346 - Seaside House contains 2 1x2x2 bricks and 28 regular 1x2 bricks in medium blue. It doesn't seem like the double height bricks provide a much simpler or sturdier build, and the part is less reusable. I would have rather seen 1x2 bricks used throughout, especially since this is a Creator set, which focuses on being rebuildable.
I also found it strange that they chose to use 1x2x2 bricks in two places, but kept 1x1 bricks stacked 5+ high in others. It seems that if the goal is to create a sturdier model, replacing these stacks with 1x1x5 bricks would have been a good place to start.
So, I guess my question is: what goes into the decision of which specific parts to use in a production Lego model?

Your example of 7346 seems very bizarre indeed since it would also mean one less part in the set, reducing the production cost.

@Joubarc Maybe the 1x2x2 happened to be available to the designer in the right color, and the designer decided to include a couple for the sake of "getting the piece out there"? It's not really important to this set but I could see it being useful, and it's a fairly rare piece...

That plane nose would be ideal for some custom bullet train models as well.

I suspect this question would be clearer if you concentrated on examples like the 7346 set; large pieces that do not have a different appearance than combinations of several smaller pieces. After all, at least the look of 54092cx1 is rather impossible to exactly replicate with the same curvature and "streamlinedness" when using smaller pieces, and while the outside of 6082 can be achieved with normal bricks, BURPs are often used as structural components whose interior space is used, as well.

Some of the reasons (including some you've mentioned):

To make building easier / sturdier, so that the set is more suitable for its intended age range
The larger pieces are sometimes cheaper than the component pieces would be
The component parts may not be part of the current inventory of parts available to designers
To make the build interesting
To provide an interesting variety of parts

In the case of the set you mention (and this is pure speculation) it is possible that 1x1x5 bricks are more expensive to make or that they were unavailable in the right colour at the time the set was designed. At the same time, the designers might have felt that the 1x2x2 bricks reduced the part count to the extent that the set was viable for the intended market.

It looks like your hunch about the 1x1x5 bricks may be correct. I checked bricklink, and these don't seem to exist in medium blue.

A non-existing part is certainly a good reason for the 1x1x5, but the 1x2x2 makes no sense whatsoever to me.

One aspect could be to make the models more interesting to build.
As far as I can see, Lego is at it's core a kid's product.No offense. I love it too and last time I check I didn't qualify as a kid.
And a varied set of bricks seems to me more appealing to "the kid" than a uniform engineering-streamlined set of bricks.
Then, I don't know the design process for Lego models, but maybe the designers just pick and choose what they feel like. (Essentially following what I described above.)
Disclaimer: Of course, pure speculation on my part.

The designers are certainly the key actors in picking the parts required for the set they are designing, but they aren't free from constraints, far from it. As such, the example of the 1x2x2 bricks in 7436 is really weird since the designer had to face the extra cost of including an additional part instead of just using some more regular 1x2

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How to tell the different ages of pieces?
I know that LEGO bricks have changed over the years, with regards to moulding pip locations, element ID numbers printed inside, etc, but I was wondering if anyone knows when these changes happened?

What year was the pip moved from on the side of the brick to on the stud?

What year did they start printing the element ID on the elements?

What year were the heads changed from solid stud to recessed stud?

The reason I ask is because I have started to collect earlier sets from the 1980s and 1990s and these are used sets. I want to know if they are the original parts or if they have been substituted for newer, cleaner parts.

You may get a decent answer for some characteristics, but bare in mind is that old moulds are often in use at the same time as newer ones, and that the overlap can last many years.

Newer isn't always better IMO.  I've found with some newer sets quality has gone down - i.e. plates bend an alarming amount, clear pieces fade in 2 years to a brownish dull and some bricks don't have that satisfying snap any longer.  I feel your question will become more and more relevant @chicks as the general consumer realizes this too and is favoring older bricks!

I just edited the question, but the OP, user2354, hasn't been around for 9 years.

According to Leggodt.nl, the molding pip was moved from the side to the top of a stud beginning about 1974, but as Kramii points out there is no hard cutoff date, as LEGO used molds until they were worn out and included existing stock in sets until it was depleted. So you may find mixed types of bricks in sets between 1974 and 1979. By about 1980, the side-pip bricks were gone.
The element numbers were printed on the bricks subsequent to the "patent pending" period, which was when many bricks had either "pat. pend." molded underneath, or places where those words had been obscured. Obscured "pat. pend." bricks appeared in sets as late as 1978, which is also when the LEGO logo on the top studs was changed (according to Gary Istok's LEGO guide). I believe this is when the element numbers started to be molded on the underside of the pieces, but again there would be a transition period. By 1980 in the US, all modern pieces were in use.
The hollow-stud minifig head appeared in 1992 and was a change based on product safety requirements (to prevent choking.) According to an article at Gizmodo, LEGO decided to re-introduce the solid-stud heads after reviewing changes in safety laws. According to Peeron.com 1992 was the last year the solid-stud heads were included in sets and they began appearing again in 2006.

Think side pips only on large plate, & square. Ends were the normal placement.

I don't think the molding pip was completely gone by 1980. I recently rediscovered my childhood Lego collection, which was mainly Classic Space from about 1980 (oldest set was 6970 Beta-1 Command Base) to about 1985 (the newest sets were 1984's 6951 Robot Command Center and a 6073 Black Falcon Knight's Castle and 1985's 6882 Walking Astro Grappler). The vast majority of bricks had a side molding pip, though most of the plates did not.
Just to give you an idea, my Knight's Castle contained a ration of roughly 4 to 1 old, side-molded 1x1 and 1x2 light grey bricks to ones with the molding pip on top.
I know this is all anecdotal to anyone other than myself, but I can assure you that the stock of old bricks was not depleted by 1980 - I would guess it was around 1984 that they really started to disappear.

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What are the angles used in angle connectors and liftarms?
LEGO makes Technic Angle Connectors, like these:

(Here are names and part numbers).
They also make angular liftarms, like these:
 (part 32348).
That last part has an angle of 53.5 degrees.  What are the angles of the angle connectors, and why were these angles chosen?  (I'd understand angles like 45, 60, and 72 degrees, but 53.5?!)

I came here because I was looking for pieces with a given angle to aid in a construction of mine. I also found this site very helpful, since it gives examples of how to form 30 & 60 degree angles, in addition to a script which allows you to ask for any angle you'd like. Hope this helps someone else, too.

The regular connector have simple angles which are multiples of 22.5°. #4 is 45°, #3 is 22.5° and #5 is 67.5°. That's pretty boring stuff, but there you go.
The 53.5 angle isn't as bizarre as you would think and there's a very good reason for it (and less boring to me, but YMMV).
That reason is that it forms a Pythagorean triangle, and specifically the best known 3:4:5 one, meaning these liftarms can be used together with regular right-angle frames to make sturdy constructions.
The one you chose isn't the best example as the beam doesn't extend to the full  hypotenuse (the connection points need to be 5 studs apart), but the longer one is perfect for that. If the small side is attached to a beam, the cross at the end of the long side will be perfectly aligned on a beam that would be 4 studs higher.
LEGO uses that to connect beams 4 studs apart in a very solid way, for example in 8435 - 4WD (the blue beam behind the front wheel) or in the more recent 8053 - Mobile Crane (left of the linear actuator)
And for the record, the angle in degrees is weirder that just 53.5°; it's actually 53.130102...°, or the invert cosine of 3/5. So if you thought Pythagoras and trigonometry wouldn't come and annoy you in your play, you're oh so wrong.

Aha!  I knew there was a reason for the angle on the lift arm.    Thank you.
I did try connecting a number of angle bricks (of the same type) together with axles to see if I could make a complete circle, and it didn't work.  I'll have to try again; maybe my axles are bent.

Try shorter axles :-) - that said, it works fine with #3 (16 sides) #4 (8) and #6 (simple square, obviously), but it won't work with the #5 one. And #2 might take a loooooong time, but there at least bendy axles will actually help.

Ah.  It must've been the #5 ones I was working with.  Thanks again : )


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Why does LEGO now use studless technic designs?
It seems to me that sometime between 1998 and 2006 (between the Mindstorms RCX and NXT), LEGO switched from using studded technic bricks (like this:)

to studdless beams (like this):

In my experience, people much more readily understand how to work with the older style of technic, and I was wondering if anyone has insights on why LEGO changed it.

I distinctly remember the studless beams before 1998; I kind of always associated the studless look with Technic.

The studless have SEVERAL advantages over the studded design especially when you want to include moving parts. Just the clearances between connections is important. Sariel sums it up in his book well. He says there are advantages to both systems (stud-full, for example, are more rigid) but the fact that the stud-less look more realistic and, of course, the clearances, make a huge difference. I think the change was NECESSARY to build more realistic models (realistic looking, arguably, but the new models are very mechanically clever in ways that would be impossible with the stud-full parts).
According to Jamie Berard, these advantages were a major part of the gradual migration, as was a flaw in the studded beam design-- the holes in studded technic bricks are placed slightly incorrectly according to the LEGO "System". That means for technic model designers, working with studded beams (and staying "In System") provides many difficult challenges.

Sariel being quite the Technic expert, his book is certainly worth reading. Would be nice to have him here, too :-)

I've been meaning to get ahold of that book.

Yes! Sariel and the book are great. LOTS of things I've wondered about are answered in that book. It's inspiring to read about what's possible (and even impossible). That's why I link to the book whenever possible . . . every reader of this site interested in Technic/Mindstorms should get it.

I think the most important aspect is a matter of geometry.
With studded beams, you're constrained by the form factor of the regular LEGO brick, which isn't a cube but a 5:5:6 cuboid. This means that every time you need to change the orientation of things, you'll have to think about how you're going to do it, and use plates and whatnot between beams. It's perfectly possible, but don't be surprised if most of the beams in older Technic models are studs up.
With studless beams, none of that. Orientation of the beams doesn't matter much anymore since they'll fit nicely on a cubic grid. This allows for greater flexibility and, indeed, more realistic models. (Some people also like smooth surfaces better.)
Also, the studded beams had some design issues. The obvious one is the offset between the Technic holes and the studs, which isn't exactly a problem but can still be a nuisance at times. The less obvious one is that the Technic hole in beams is actually slightly too high, meaning it doesn't interact well with the rest of the system. See also this answer and the linked pdf inside for more information on illegal builds. These two design "flaws" didn't matter much when the beams were first created, but nowadays LEGO perceives this sort of incompatibility much more seriously. They still produce studded beams, but I wouldn't venture a guess on how long that will last.
One side effect of the transition is that most studless Technic constructions have odd dimensions, because the studless beams themselves have odd dimensions (presumably, because the number of holes on studded beams were also odd due to the offset). As a consequence, the whole Technic system is undergoing a complete overhaul.
At first, more odd axles have been introduced (most notably 7 and 9), then the universal join was shortened from 4 to 3 (the old one was last seen in 2008, so it's probably gone for good), and more recently the differential has also been remade (there's still one in the 2011 Unimog, but I don't know if they'll actually discontinue it considering it has a function the new one doesn't have.). I don't see any other part left that needs to be updated from even to odd, but considering how often they use a #2 connector just to connect axles, I wouldn't be surprised if they made a 3L version of the axle connector at some point

I don't see any other part left that needs to be updated from even to odd: The studded frames (4x4, 4x6, 6x8) have so far given only the 5x7 studless frame (the 5x11 can be considered as a derivative of 5x7). Bigger frames would be nice to fit in PF motors...

Good catch about the frames, I hadn't thought of these and there's indeed room for more of these. Maybe even a cubic one? (5x5x5?)

Interesting.  I'd often thought that the holes in the beams should be better centered.  Is there any reason that the studless beams can't be made with an even number of holes?  I must say that, while vertically reinforcing a part with the older system took some thought, building up or rotating 90 degrees was straightforward, without using any special joiners.

Right, as long as you kept studs up, everything was easy, and you could argue some constructions were actually easier, but at the cost of one degree of freedom. I suppose Sariel's book (see Tooshel's answer) details the pros and cons much better.

3M axle connector as predicted : http://brickset.com/parts/design-26287

Such a pity they are diluting the parts... There already were parts perfect for the job... Connector #2 or Driving Ring Connector were both 3 studs long and joined two axles just fine.

They did use Connector#2 for that in the past indeed, but it can't be used everywhere (between 2 beams for example); and I suppose the driving ring connector is similary too wide

Manufacturing the studded beams is significantly more complex and hence more expensive. They have more plastic in them (they weigh more) which also pushes up the cost. But the mould complexity is the real killer. If you look carefully there's a void over the top of the holes in the beam. That means moulds with moving parts, and the more parts the more it costs.
The design is also not ideal from a rigidity or symmetry point of view. There's a solid bar of plastic along the top under the studs, but just two thin sidewalls at the bottom. That means the centre of flexion along the beam is much closer to the top than the bottom, and I suspect that getting the moulding temperature and pressure right to get straight beams is harder than for symmetrical parts.
Note that some of this also applies to standard 1x16 bricks, except that the mould is much simpler.

Actually, the technic brick with studs is way more rigid than the modern one.

@Haukinger weight for weight or piece for piece? I suspect you mean the latter and that's an unfair comparison. Also, I was talking about manufacturing them rather than using them.

I completely agree with you that they did it for cost only, for the last 30 years they only ever made stuff cheaper (to manufacture, not to buy, of course).

I have to chime in here that I've thought about this for a long time. I  believe the all out move to studless is primarily driven by patenting, and only secondarily by improved realness.  Lego had used the studded design for decades prior to the switch; they began full transition in close proximity to the original patents expiring and beginning to lose patent lawsuits.  What is the only solution to that?
Branding (read: licensed themes) and new ideas (read: new patents).  When it comes down to it, that toy company we all love(d) is actually a very well-managed business with strong survival technics (pun intended:)

This is a very good point, do some research before downvoting. Losing control of the iconic ''brick with studs" piece (through patent expiration and lost trademark cases) is a very real problem for Lego, and I'm sure it has an impact on their decisions for the future.

I see a lot more cheap clones using studless beams than studded ones. I'm guessing ease of manufacture accounts for that, rather than expiring patents.

Studless beams allow for bricks with corners:

With studs Lego could produce similar bricks however it seems less obvious how they would look like.
The benefits of having these curved bricks are just better designed models. Set 8880 (the big Technic car from 1994) is an example how Lego had to go trough great lengths to get corners and angles in their design. With studless bricks you can have the angles and corners already. I think it is an improvement.
I suspect Lego was because of these studless bricks with corners able to phase out the awkward Technic Connector Toggle Joint Toothed brick which turned out to have too many issues after all.

Welcome to Bricks.SE. Beam pictured above doesn't form 135 degree angle - use two of them and you won't get nice 90 degree assembly.

What I find really weird is that the studless beams aren't square in cross-section. How difficult would it have been to make them exactly square? But instead the width between the surfaces with the holes in them is the same width as a studded beam, while the width between the smooth surfaces is very slightly less. Although this doesn't matter in all the typical vehicle-builds that lego make, it's decidedly untidy when combining studded and studless, and it makes for unnecessary headaches if you try to build anything unusual (for example you need a studless beam to slide exactly in a hole, smoothly but without undue sideways wiggle). It seems very un-Lego, where normally the dimensions are either set by history, or designed so that all sorts of unexpected constructions remain possible.
I notice that the whole studded versus studless argument didn't develop in the straightforward way most of us expected. Lego Creator has become quite "technical" in its construction, while remaining studless - a lot of the old studded technical pieces are staples of Creator, and odd studless bits drop into it too. To my mind, Creator is often where Lego is at its most creative. So presumably the cost of making studded "technical" Lego wasn't so disastrous.
I do think the Patent argument has a lot of truth. Studless developed at a time when studded was going out of patent and all the world and it's plastic-moulding friends were producing knock-off Lego-compatible building sets. Since then, we've realised that most (all?) of them are excruciatingly low-quality, so they simply aren't the risk to Lego that they first appeared. And some of them are no longer all that cheap compared to the real thing.

I think big vehicles in Creator series are the new "Model Team". Similar size, idea and approach. Both have some use of studded pieces for the base while exterior is made of usual bricks.

The fact that cross section of studless Technic beams is "square, but not square" I believe is exactly because of the use-case you have mentioned. Having them slightly smaller in one dimension allows them to move/slide without much friction. You can try this by making two structures with 3 studless beams with top and bottom fixed and middle one sliding. One structure would have all pin holes facing horizontally, while the other vertically. Then try sliding the middle one - it will have more friction with one setup than another.

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What is the best way to transport a large quantity of LEGO bricks?
I have a decently sized collection (thousands of bricks/hundreds of sets/a bunch of bins) from my childhood, but they're all at my parents' house. I live in the US and a couple states away from my parents (more than 1000 miles). What is the best way to package all of the bricks? What is the best way to move all of those packages? I ask because I'm thinking the weight of them all might make it tricky to transport. Hopefully someone out there has been in a similar situation.

You may want to contact experienced BrickLink or eBay sellers, since they routinely do that kind of thing.

Are there any of those on this site?

I have no idea, but I suppose if there are, they will answer...

When I moved house, I just sealed the gaps in a bunch of packing boxes with duct/packing tape, and put the storage bins in there - that way if anything did escape from the bins it wasn't going to get lost from the box.
I would say though that in general my collection wasn't organised in anyway, although there were a few built sets that survived fairly well.

No personal experience, but one vendor I've seen a couple years now at Brick Fiesta just ships boxes full, roughly U-Haul medium sized. He has some cardboard 'trays', but I'm pretty sure they are not structurally useful. He also had stuff bagged up into various types and some level of sorting, but that's not really important to shipping either.
Of course, if you have some relatively delicate bits (like [part:2337:46]), take care to pack them with as little stress on them as possible.
(ok, clearly I'm not getting how to do part linking)

Pack them in a box and surround them with things that are soft.


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Is the PWM on the PF Servo motor different than the PWM from an Arduino?
I have a Arduino motor shield connected to XL, L and M motors and can control the speed with PWM (Pulse Width Modulation). I made my own connector by cutting a Lego PF connector in half and wiring up the two inner connectors to "pins" that are easy to connect to a breadboard.
When I connect those two pins to the PF Servo Motor that comes with the Crawler, well, nothing happens no matter what pulse I send (Arduino handles the pulses . . I just set a "direction" pin and a value between 0 and 255 . . . and PWM or not the net effect is that with a voltmeter you see voltages between about -9 Volts and 9 volts, same as when you measure from the IR receiver).
Anyway, what am I missing? What is different about PWM on a servo motor?

That doesn't quite seem as a real question so far... (but I'm fairly confident you can reformulate once you have the answer)

Sorry man I was in a rush! Panic! I'll fix it after my presentation tonight. And, I do have the answer so I'll post that too. Sometimes in asking the question and having to think about it you come up with the answer on your own.

Well it's ok to ask and answer your own question but you'll certainly want to rewrite the question so that it looks like one.

@Joubarc Okay, it's fixed. You can further change it if you want (you're a moderator!) but if you have other suggestions I'll fix it further. And I should add some pictures . . . describing these things is difficult and a picture would make it way easier. I just hope this kind of question is relevant here . . . I was going to post in the electronics SE too but figured it out before I got to that.

Editing questions to make them better isn't limited to moderators, quite the contrary - everyone is welcome to contribute in that way, too. That said, the question & answer looks fine to me now.

@Joubarc And you STILL added your own answer! You are all over the place! Of course your answer is good too and adds great links. And the graphics from that site are perfect.

According to Philo's detailed analysis of the servomotor, it takes its commands from the C lines but needs to be powered as well:

Being a Power Functions range member, it is fully integrated with this system, and receives its commended position through C1/C2 lines, and its power from supply lines. On a normal motor, C1/C2 duty cycle directly control motor speed, here they set the angular position of the shaft.

This makes sense since there's electronics involved and these need to be powered by a regular, reliable power supply which is exactly the purpose of the +9V and Ground wires. The same holds for the IR receiver (although that one ignores the C1/C2 lines completely).
For more information on the PF wiring, you should also check Philo's presentation of the Power Functions system.

I did a bit more reading and most servo motors are a three wire affair and that's what got me thinking I was missing a wire. I didn't add my pin wires to all 4 wires on the pf connector because for all the other motors they are not used and they just get in the way. Luckily I had parts to make a new connector . . . although RIP to one of my Lego LEDs :(. And these links are wonderful reads I hadn't seen before so thanks!

Just a thought, you may want to sacrifice extension cables instead of leds.

Oh, I've sacrificed plenty of extension cables . . . but I ran out! And not even the Lego Store carries them.

@tooshel necro-comment: the Lego Store seems to carry extension cables now at a somewhat reasonable price compared to normal Lego prices.. I don't feel too bad about cutting one of them up as I get two usable wires out of each

Turns out the problem is that Servo motors need at least THREE wires. Two for the PWM and one for full power. I made a new connector (and I can attach a picture if anyone is interested . . . just don't have one handy right now) that had all four of the wires from the Lego brick connected to breadboarding pins and then I wired the two new wires to +9 and ground. That did the trick! As soon as it powered up I could hear the servo motor moving to center. Then, I sent pulses with the Arduino and I once again had control of the steering!

How did you end up sending the pulses? I couldn't get the servo to respond to neither analogWrite() nor the Servo library's write(). From some Googling, I got the impression that this is because Arduino's built-in PWM frequency is 500 Hz while the PF servo expects 1150 Hz. I'll try "manual" PWM to get the frequency that's needed. Also, it's still not clear to me whether the PWM is on both C1 and C2 or just on whichever is not LOW.

@AtesGoral Wow! It's been a long time since I looked at this. All of my code is on github if that helps. https://github.com/tooshel/androdino/tree/master/arduino Another notable problem I had was the 9 volts from the Lego power pack would end up as about 6 volts by the time it went though the Arduino Motor Shield so I had to rig up an extra Lego power pack with only 3 batteries and aluminum foil for the other three, and make another custom cable that put the two batter packs in serial. Yeah, it was crazy. Thank goodness for sbrick!

Oh my goodness! I hadn't heard about SBrick. I think I'm going to order one soon :) In the meantime, I'm still trying to solve my problem with Arduino because I'm basically doing it as an electronics learning exercise instead of powering up an actual model. I'll see if the voltage drop is the cause of the problem. Thanks!


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Building instructions from an LXF file
I've downloaded an LXF file from rebrickable.com. Which software do I need (for Windows and/or Linux) to get the building instructions based on the LXF file?

You probably want Lego Digital Designer:
http://ldd.lego.com/
Once you have the .lxf file open, you'll want to select View -> Building Guide Mode from the menu. This should give you step by step building instructions.

Although lxf files must be loaded with LEGO Digital Designer (LDD), it's not always the case that lxf files are loaded correct/completely with LDD. This because the fact that LDD uses a database where the parts are stored, but it doesn't contain all parts and the database changes from time to time. When trying to load older files, you have about 100% guarantee that the lxf file won't load correct. Thats why i'm using LDRAW and MLCAD. There is though a conversion program to convert lxf (LDD) to ldr/mpd (LDraw/MLCAD). However it relies on a xml file for the conversion. If this file is not complete or correct, the conversion will not be correct.


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Why did LEGO create different canister for the Visorak?
I have the six original Visorak (Sets 8742, 8743, 8744, 8745, 8746 and 8747) with different canisters (or boxes).
For example, my Suukorak (8747) has a white canister, and my friend's has a black one.
Here's a picture showing the canisters:
Some canisters are colored the same as their lid while others are black.
Why?

That's funny... all my visorak have black canisters and colored lids...

I heard a similar question about old cars and how one owner had a hood made of steel and another . . . same make, same model, same year . . . had an aluminum hood. The answer as to why was simple . . . it's the metal the manufacturer had at the time. My guess is once the molding machines are loaded with a color they keep using it until it runs out. Some of the colors were versatile and looked good on multiple sets so they could make more of those before switching colors.

So it's not a serial propertie or something like that ?

I was figuring that color didn't matter just like my example about steal vs aluminum . . . but since there are THAT many different colors I'm starting to wonder. It's like minifigs where it's the same character but with a different facial expression and/or costume. Now I'm starting to wonder if it's a part of the "story" that goes with Bionicle.

Nope, the Visorak's canisters are not presents in the story, some of them like the Toa Mata, Piraka, Bohrok, Rahkshi or the Vahki are, but not Visorak's.


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Why are new LEGO bricks softer than old ones?
The older bricks that were made back in the day, "pre-2K", seem to be made out of a harder and more durable brick that would hurt your feet when you walked on them. Now it appears that since the other brother of the LEGO family took over, things have changed and you are seeing tons of themed sets coming out, (which is awesome), but at the same time they seem to have changed to a softer mixture of plastic.
Some AFOL's think that this is due to the fact that the bricks are now being made in China; they used to be made in Mexico.
If you compare a sword piece made in 1995 and compared it to the new stuff, you'll notice that even the color is different. The old Medieval swords were bright and shiny and hard as a rock. The old pirate swords you could be used like a tooth pick. Now they both seem to be made out of an entirely different plastic and bend with no effort.
I personally have not spent more than $200 in this last year down from $2000 the prior year for this reason. The only reason I bought anything at all was the new Friends sets. I loved LEGO until they took out the main reason I was buying their toys; their durability aspect. It was one of the only toys on the market that didn't turn towards profit and become mass produced in China, now I will have to start buying Playmobil.

You may want to clean up the question by removing speculative bits in it; as it is now it's quite hard to figure out what it is you're actually asking.

AFAIK, relatively few bricks are made in China.

As @Kramii mentioned, my understanding is that most of the parts coming from China are textile parts like the capes and strings.

Some very special parts (licensed headgear, big dinosaurs) may also be produced there, but definitely no regular bricks whatsoever.

Considering Lego is the world's largest toy-maker, they have grown 15% per year for ten years, and AFOLs make up only about 5% of their revenue, I think your entire last paragraph needs to be reconsidered.

Some of it may be your own perception changing, such as a room you remember being big when you were a kid, but which you find small as an adult. So when you perceive bricks as being softer, it could actually be that they aren't, but that your perception changed. (If you were to walk barefoot on LEGO bricks for one hour per day, your feet would eventually harden enough that you wouldn't feel it anymore.)
However, some may actually hold true, especially for weapons. Swords that are produced nowadays are indeed not as hard as they were back then, and that is simply for safety reasons, as safety controls put in place become harder with times. In extreme cases, they'll even use rubber, for example for the tip of the big spike introduced with exo-force. Another more subtle example is the circular saw blade: ever thought how dumb it was that they didn't use a cross axle hole in that? Wonder no more: it's just so that kids wouldn't put it on a motor (I know I would have as a kid).
As for the perceived quality changes, well, it's a bit of the same, there's a lot of it which is just that, perception; but there are of course real quality issues that pop up from time to time, which LEGO usually assesses the best they can. One key factor here is that there's a huge stock in their factories, so any changes they make can take a while before they appear in released sets. For example, they have switched at some point from buying precolored plastic granulate to adding the color themselves to white granulate, but at some point they didn't add enough color, resulting in translucent and more fragile bricks. They fixed that, but a lot of the already produced bricks made it into sets.
Also, LEGO can only learn about quality issue when customers actually complain about them, so when facing a real quality issue, it's always best to contact the customer service and explain the problem. Not only will they usually be able to provide replacements for you, but this will eventually reach the production quality assurance.

I recently sorted through some of my bricks from the early 00s (so they're not nearly as old as 80s 90s bricks) and their clutch power is immense compared to my brand new bricks - after connecting two it was extremely difficult getting them apart even with a brick separator without damaging the plastic (with the separator!). I don't think it's just perception. I'm pretty sure there's real aging of the plastics at play here (though I'm less concerned about that aspect and more interested in knowing how I can soften them back up again - which I may open a new question for).

Plastic pieces will become harder over time. Not sure why, but I think it is that the substance that were added to make the plastic a little softer evaporates over time.
I have been told that the people designing sets for LEGO never use pieces older than 2 years. This is because harder pieces will have more clutch power than softer pieces and because of that, they might accidentally design a set that will fall to pieces when built with only new pieces.

Don't you contradict yourself here? They never use old pieces, and they don't use new pieces?

@Gruber - nope teabox said that they don't use old pieces because they might have more clutch than newer ones - so by ensuring that their parts are no more than two years old they can ensure that the model will stay together with new bricks.

I can't definitively answer, but I can say that this has been a common observation around the late 1990's and early 2000's-- nothing to do with Chinese manufacturing.
I personally made the observation when comparing construction in large-scale creations in 1999/2000 and later in 2005. The large scale creation in 1999/2000 was a very large building, commissioned for a music school, and used elements that were likely molded in the 1996-1999 timeframe (they were brick and plate accessory packs). In 2005, we worked on the LEGO Millyard, producing similarly large buildings using very similar techniques for roofs.
Each project used stacks of large plates (black in 1999 and dark stone in 2005) for the roofs, and the behavior of the elements was distinctly different. In 2005, the plates had a tendency to "moosh" their way apart unless connected fully (and even then sometimes worked their way apart as the sections were handled), whereas in 1999, I didn't have that experience.
Around that time (2000 or so), hobbyists were commenting on the fact that it seemed like newer molded elements were softer, and didn't have a tendency to "click" together quite as much as they had in the past. And again, this is prior to Chinese manufacturing or dye-injected coloring changes.
The theory had by some was that this was a conscious change on LEGO's part to make the elements easier to use for younger children. Around that time (1997), LEGO was attempting to lower the age range on Town sets to bridge the gap between Duplo and System, and such a change may have been a part of that effort. According to one account by an AFOL that was involved in plastics manufacturing, this is often achieved in ABS plastic by adding more vinyl to the ABS mixture, giving it a more spongey quality.


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Electric, Plug Holder 4.5V/12V what is it for?
I have seen the Electric, Plug Holder 4.5V/12V on bricklink a few times and have often wondered what it is for.

According to Bricklink, it was only ever produced in Light Gray and appeared in 3 sets between 1987 and 1992.
Two of the sets were just Service type sets containing cables and small elements with no instructions or suggestion of usage of the Electric, Plug Holder 4.5V/12V itself.
However, it also appeared in set 9700 Technic Control Center. Unfortunately neither Peeron nor LetsBuildItAgain have a listing for the instructions. So I can't see the step where any of the 5 that were included with this set are used.

Well, it holds plugs, right?

While researching information for this question, I stumbled upon the answer but thought I would post anyway to share my findings.
The Bricklink entry for the 9700 Technic Control Center set has a secondary picture which is the front cover of the instruction booklet.

The 5  Electric, Plug Holder 4.5V/12V elements can be seen in use as holders for the shorter wires connecting to the motors that make up the model. Using the holders provides easy access to plug in longer wires from the control center unit. The holders are necessary because, unlike the connections on later 9v wires that can be built into a model like standard pieces, the connections on the older 12v/4.5v wires cannot.

So basically it serves to hold plugs in place when they aren't plugged in anything, typically when extending wires. Contrast with the alternate build for set 7745 where the plugs just lie there inelegantly. In a way, I suppose you could compare this part to the new pneumatic connector which holds pneumatic tubes firmly into place. Of course, electricity tends to make wires move less.

Also, notice the coloured plugs and tiles. As the plug holder holdes the plug connecting to the motor into place, you can safely remove the ones coming from your control center, and you won't have any problem knowing which one goes where thanks to the colouring scheme.

@Joubarc Indeed - this attention to enabling the wires to be connected and disconnected is likely due to this being a dacta set and so will get a lot of use. Those coloured plugs are also unique to this set as far as I can tell.

Basically, they're used to hold the wires together but also to hold them when you need to connect 2 wires together.


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What material is used to make capes and cloth in LEGO sets and where do I get it?
It seems like a conspiracy to keep everyone from knowing this.
Custom cape sellers don´t say what it is, the women from the draperies I questioned always say something along the line of "coated propylene" which is no longer in the making because the only company who sold it went bankrupt in 2003.
Even LEGOs customer service can only say "Acrylic matte medium" which apparently is some kind of paint artists use to paint on canvas.

The term acrylic is used for many mediums, like acrylic paint (liquid), acrylic fiber (clothing), acrylic rubber (flexible) and acrylic glass (really hard).
So, as you see, it is possible to make those capes out of a type of acrylic material.

It is fabric - probably cotton or polyester - coated with an acrylic substance that makes it more durable and tear-resistant. You can easily print on acrylic-coated fabric using standard laser printers.
You can purchase acrylic-coated fabric through suppliers that sell sign-making supplies as well as art supply shops.

see this tutorial on Creating custom fabric elements for Lego minifigures
http://www.minifigcustomizationnetwork.com/howto/899

Thanks for pointing out that resource. I would recommend that you include more than just a link, though. As it stands, this doesn't provide an answer to the question. Answers should be able to stand on their own without the need for external resources.

@jncraton You're right, it's not exactly an answer to the question of what Lego uses ,but this is the best information i found on the subject and i didn't want to copy/paste the entire page

I've used iron-on patch material (the thinner twill variety that comes in bright colors) with success for my kids' minifigs. I cut it out with fabric scissors and use a good hole punch for the holes. Takes about one to three minutes a cape depending on complexity and is $2.47 at Walmart for a 4 pk of 5"x5" patches.

Paint everyday fabric with black acrylic paint. Use a paint brand like AppleBarrel. This will not give you fabric exactly like LEGO, but it is durable, cutable, and can be hole punched. You can paint over it with any color once the initial paint has dried.
NOTE:
This was not my idea. It came from a YouTube video by NobleArtist. Check out his channel.


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Whatever happened to Architecture 21015 Eames House?
The set was scheduled to be released in 2012, no such luck. Any idea on why it never came out? Was looking forward to building it.

According to: http://toysnbricks.com/forums/viewtopic.php?f=58&t=5288

so apparently B and N made a mistake, and the Eames House is actually
  not going to be a set (or so Adam Reed Tucker says). He answered a
  question about it today at the Master model Builder competition in
  Chicago

So sad.

Interesting. Still, considering B&N didn't invent the info, it probably means the set was in development at some point and LEGO did scrap or postpone it. The fact that number 21015 hasn't been attributed (yet?) tends to prove that too. So we still don't know even in which stage of the development process that set was, or really anything that could have happened to it or not within LEGO.

I appreciate the input. I'll still keep an eye out if it does come out, but, disappointed that my hopes were up for nothing.

I just checked the LEGO website out of the same curiosity and they seem to have the Leaning Tower of Pisa for 21015 but they have the image for Sungnyemun 21016 I think they might be updating the page right now. I can't wait to build the Tower of Pisa!


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How do I get started with Mindstorms NXT 2.0?
I need help programming a NXT 2.0 Lego Mindstorms. I want to make the robot turn, stop, go back, etc. when the color sensors see certain colors. For example when the robot sees red it stops then turns. Please help me I am new to Mindstorms and programming.

As such, this question isn't exactly a good fit for this Q&A site, as it's too generic in nature and doesn't give information on what you actually tried. The best way for you to learn is to start using the Mindstorms kit and following the instructions (LEGO did a good job with it so that children should be able to start by themselves without help). If at some point you encounter a specific issue which you can't solve by yourself, then you'll probably be able to ask a more specific question. The FAQ explains which questions should be asked here.

As was pointed out, this question is not specific in nature, so it's hard to give a definitive answer. If you haven't already done so, it would probably be helpful head over to Lego.com and grab get the NXT 2.0 User Guide and perhaps begin looking through the sample programs.
This book may also be helpful to you:
The LEGO MINDSTORMS NXT 2.0 Discovery Book: A Beginner's Guide to Building and Programming Robots
If you run into specific problems as you are getting started, feel free to create a new question, and we'll try to help you out.

Books are indeed a very good starting point, I'd also recommend The King's Treasure. Although I've only read the previous one (Mayan Adventure) from James Kelly, I found it very educational.


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LEGO Digital Designer is unable to connect to the Internet
I just installed LEGO Digital Designer on my Macbook Pro running OS X (10.8.2).  Every time I start up the application, it immediately displays a dialog box stating "Internet access failed" as you can see below. Clicking retry does not help as it simply pops up the same dialog box again, clicking cancel shuts the program down.  Clicking ok simply allows the program to run in offline mode which is not what I want.

I have tried disabling the firewall on my computer, but that did not resolve the issue.  I do not have an antivirus program running that would block the application and all of the other programs on my computer access the internet just fine which leads me to believe that there may be something wrong with the application.
I did some research and couldn't find a definitive solution for this issue.  One proposed solution is to disable parental controls, but I don't have it enabled on my computer.
Have any of you come across this issue and come up with a resolution?

I saw this same problem yesterday, but at some point during the day it stopped happening, and I haven't seen it again. Perhaps a problem on the server end?

Checked the application this evening and the issue is no longer occurring.  It must have been an issue with their servers because I hadn't changed anything on my router or computer since I created this posting.  In fact, I contacted LEGO customer service and they instructed me to change some firewall settings, but I knew that wasn't the issue because my other Apple Computer was working just fine.  I am going to respond back to the LEGO customer service email and inform them that their error handling should be more informative, especially if it an issue with their servers.


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What element modifications are incorporated by the LEGOLAND builders?
I know they glue their sculptures together, and sometimes support them with an inner frame. Is that the limit to their element modifications, or are there more tricks to the awesome LEGOLAND builds on display?

The glue is one obvious thing, and I think they recently also experimented with a new sort of transparent stuff to paint the finished models with so that they would be more resistant to direct sunlight. I don't think they'll paint bricks to change their colour, though.
However, In the same category of things any respectable AFOL would never do, I'm fairly confident they'll also resort to cutting elements if needed. I'm unsure if that happens often and it's probably limited to parts where the cut isn't visible from the public. Another thing is the use of generic plastic sheets for some large windows, for which no LEGO elements exist.
Then, as Kramii said, electrical and mechanical components are never LEGO. For the vehicles, they do have a generic frame (metallic, with motor, battery, and all control electronic) on top of which they build a LEGO exterior. Presumably, trains follow the same logic.
So yes, they are very lax with what they can or cannot do. I know the work area of the designer in Windsor is visible from the public, not sure it is so with other parks (I don't remember that in the two others I've seen); but if you get the chance it's nice to see them. With some luck, they'll have some time to spare to chat with you.

LEGOLAND builders appear to be quite "rules free" in their use of parts, as long as the final model looks as though it is made of LEGO.

Not exactly a "part modification", but LEGOLAND builders have sometimes had access to parts in colors not available to regular builders.
The builders often add lights or other mechanisms to their constructions. The moving vehicles are particularly interesting in the way that they follow predefined tracks under the roads, and stop on recharging points when their batteries are low.
The trains don't use standard LEGO rails.
Some of the models outside the "miniland" areas in the park are made from what appear to be extra-large LEGO bricks.

The first one isn't true any longer - they can only order parts which are currently in production (for sets thus). Note they may still have some stock of older parts produced in colours never released in sets; but new part orders are strictly limited.

I remember reading somewhere about how some participially large models (like the LEGOLAND Windsor Dinosour) had steel frames for support.


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Is there a way to change the Lego NXT sensor polling frequency?
I am using LEGO NXT 2.0 with the native NXT flowchart-style programming environment, I would love to be able to poll the sensors more frequently. (In particular, it seems that the light sensor is polled very infrequently, only about once or twice per second, and this limits the speed of a line-following robot I can build)
Is there a way to change the LEGO NXT sensor polling frequency using the LEGO software?
I am looking for a way to do this using the LEGO software, I realize that there is a way using MS robotics.

Most sensors have the capability of sending you notifications or updates as the value of their sensor changes. This is accomplished by repeatedly contacting the NXT brick and querying the sensor. The polling frequency allows you to configure for each sensor how often this is done.
In most cases, you may leave this value set to 0, which indicates the default polling frequency. However, there may be times when you wish to get sensor reading back from one sensor more often. In this case, you can adjust the polling frequency, which is specified in milliseconds (1/1000 second).

from Device Services: Microsoft Robotics on msdn
The article goes on to suggest the range within which this can be effective.

But that's using Microsoft Robotics, not the native NXT programming environment, right?


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How to simulate Lego Mindstorms programs written in C#?
I am going to do some programming for Lego Mindstorms in C# using
http://www.mindsqualls.net/
and have a question. Is there any good simulator to see result of my program without uploading the code to the robot?

I'm not sure a simulator would be able to properly mimic the physical aspects of a robot; but it's an intriguing idea. Sadly, I don't know if anyone has ever done this.

I think you might be able to do something like this with Microsoft Robotics Studio. Here is a video that appears to do what you want: http://www.youtube.com/watch?v=AcETVcobqfc

Unfortunately, there are no simulators for Lego Mindstorms in C# that fit your requirements. As Sebastian Wahl mentioned, Microsoft Robotics Studio is probably your best bet. Hopefully there will be a tool like this in the future :)


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

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

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

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

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


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Which LEGO Technic sets include instructions to add the Power Functions accessory box?
Some LEGO Technic sets apparently come with instructions to add a motor, using the pieces from the Power Function Accessory Box (set 8293).
Is there a list of the sets which do contain such instructions?

I recently purchased both 42006 Excavator and 9396 Helicopter, both of which comes with instructions on how to add motors.
The reviews for 9395-1: Pick-Up Tow Truck suggest it can be motorized.
A lot of the more recent Technic models are either too small for a motor or already come with power fuctions.

If you are looking for current Technic sets that have the Power Functions option, you can search LEGO.com by the term "power functions" and then filter by "Technic". This will also bring up sets that include Power Functions accessories in the set, so you have to look at the descriptions to find out more. As of the date of this post, the search also returns some retired sets.

Yes, thanks, obviously sets that include the power functions can use the power functions. But I'm looking for other sets that can also take power functions.

I understand. Perhaps my response wasn't clear. This search brings up both those sets that include Power Functions accessories AND those sets which have the Power Functions option (but do not come with the accessories). You have to look at the descriptions to see which is the case. It is not a list of only those with the option, but it narrows it down to the point that you can easily find them.


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Does the LEGO company actively follow or copy clone bricks?
What does The LEGO group do to follow clone brands?
Do they buy at least one of every set produced by The Other Guys?
I'm more interested about what the LEGO company does to keep up with what competitors are putting out, and whether or not they might decide to incorporate new elements in their own product line. We always consider that clone brands copy LEGO bricks, but does the opposite happen?

Not certain what your question is concerned about.  Are you talking about counterfeiters or about other brands like Megabloks and Kreo trying to get a piece of the pie?

Sorry, I mean in terms of keeping up with what the competition is putting out.

In my opinion, LEGO must follow clone brands very closely, and this for a number of reasons.
The first, which is obvious and has already been mentioned, is that they want to protect their own intellectual property. As such, they'll want to take legal action as soon as possible when one of their trademarks/copyrights is infringed.
The second one is actually also about intellectual property, although not their own. Indeed, while LEGO is usually considered as the leader in the field of interlocking bricks, it can indeed happen that a competitor creates something new, which LEGO might not have considered. That would be where you would suggest that LEGO should "keep up", but in reality most of the time it's exactly the contrary: since they may not infringe on the competitor's own intellectual property, they won't be able to imitate them.
So saying that design decisions can be made independently of what other manufacturers are doing is, in my own opinion, utterly false. I can't imagine a field of business where you can completely ignore what your competitors are doing, just because you believe you're ahead of them, and if you do, you're either very cocky, or very naive.
Note I'm talking about serious competitors like MegaBloks, not the one who just copy badly everything LEGO makes. MegaBloks, for example, does have interesting parts (for example, plates with studs on both sides, Plate 1 x 2 connector, male:male and Plate 2 x 2 connector, male:male). These parts are interesting and many LEGO builders would like to have them, but it's unlikely LEGO would be willing to produce them now that MegaBloks has. Of course, I'm no lawyer and I understand copyright law may be much more intricate than that (there are parts which both companies produce, for example), but I'm confident this is a valid concern in the design process.

COBI also has some male:male plates, 2x2 and 1x4 at least.

+1: Some excellent points that I had overlooked. I've deleted my own answer as it is just plain wrong.


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Is it legal to sell your mocs?
First off, I assume that it's legal to sell used LEGO bricks and it's also legal to sell self-made LEGO instructions and parts-lists.
As far as I know, there are people selling LEGO sets of their MOCs online. But I also witnessed a discussion, where the general consensus was that this would be illegal.
So let's say I build a MOC and want to sell it. Would the following be okay?

Selling the exact MOC I've built
Selling the parts one would need for the MOC (+ instructions and part-list)
Packing the parts and instructions into a self-designed box and selling them

Selling used LEGO is definitely legal, at least in most legal systems. One of the most basic property rights involves the right to transfer ownership as long as both parties agree on the terms. Even selling items under copyright (instructions, box art, games, etc) is legal under the first-sale doctrine.
I don't see any reason that any of the 3 things that you listed would be illegal. Here's a similar example which hopefully makes things more clear.
Let's say that someone builds computers and sells them. No one builds a computer from scratch, so the builder has to buy lots of components (CPU, GPU, RAM, hard drive, etc). Although each one of these components is likely covered by hundreds of patents, that doesn't actually matter because the builder bought the right to resell the parts. As someone selling MOCs, you have to buy LEGO bricks to resell. This is a valid use of your property rights.
To address your issues specifically:

Selling a MOC you build - This is legal because you are simply selling your own physical property (the used bricks) and your intellectual property (your MOC)
Selling the parts one would need for the MOC (+ instructions and part-list) - Again, you have the right to sell the parts. The instructions and part list are your intellectual property, but there may be issues with trademark (e.g. you can't brand it as a TLG authorized set)
Packing the parts and instructions into a self-designed box and selling them - This is essentially the same as 2 except with additional intellectual property of your own (box art, etc). Again, it needs to be clear that this isn't an official LEGO set.

In regards to the branding and trademark issues, TLG has a document available which provides a useful set of guidelines to use when referring to LEGO.
To be clear, I'm not a lawyer, and if you're planning to start a business selling packaged LEGO MOCs, you might want to consult a real lawyer first.

Yes, I think item 3 would be the most concerning - provided you're not passing off the boxed set as anything remotely LEGO (similarly MegaBloks/KRE-O) endorsed/affiliated - there are a number of successful "Unofficial LEGO" books on the market - however it might also depend on the theme of the sets.

The only thing that I would add to this otherwise excellent answer is a link to TLG's official statement on copyright, trademark, and fair use http://aboutus.lego.com/en-us/legal-notice/fair-play/
As long as someone does not run afoul of those terms you're pretty much in the clear. Do note that most of those terms do refer to "non-commercial" use though so be careful how you apply them.

In any case, it does happen regularly at key LEGO events, and in plain sight, as well as on the Internet.
Considering LEGO employees (and big bosses) attend these events on a regular basis, if they had a problem with this, they would have said so by now. Obviously, Kjeld Kirk Kristiansen doesn't mind.
Of course, it needs to be very clear what you're actually selling and you certainly don't want to pass it off as if LEGO designed the set, but for the rest there shouldn't be any problem. You can even sell instructions only for a small fee if you so desire.
Note that I'm not saying it is legal, I don't know about that (though I would tend to agree with jncraton on this); rather, I'm saying that LEGO has no problem with it at all as long as you play it fair. Keep in mind there are some people who even create and sell their own parts, and LEGO doesn't go after them either.
One last thing to consider regarding legality however is that you also need to check if what you're building has a copyright on it. Selling a MOC of a Smurf statue, for example, might very well be OK for LEGO, but most certainly not for the Smurf copyright owners.

Given operations like http://www.brickmania.com/ the answer is decidedly yes... as long as you follow certain rules.
Among those rules are NEVER use the actual LEGO logo, and refer to the elements as LEGO® elements.
A somewhat fuzzier rule is that aside from mentioning that genuine LEGO® elements are contained in the product, your product should not be easily confused with an official LEGO® set.
While it does not specifically mention resale, http://aboutus.lego.com/en-us/legal-notice/fair-play/ has some useful information, plus a link to a PDF Fair Play brochure.

Are you sure it is not legal to say "it's made of Lego(r) bricks"? If I make a table, I can (I think) say it's made of wood, or that building is made of SuperConcrete Ltd.'s concrete and so on.

Sure it's legal.. I said ASIDE from that.

I believe generally selling your MOCs would be fine, as other answers have pointed out.
It would be interesting to see what problems you'd come across if you tried to sell other people's MOCs though, which I guess would fall under copyright infringement.


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

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

Market places for MegaBlocks include:

The Bloks Forum
eBay

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

Your question is answerable with a yes or no, so I'm going to have to say no.
The main reasons something like this doesn't really exist are likely as follows:

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

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


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How can I make a mosaic from a given number of 1x1 bricks and a picture?
This question is similar to How can I convert an image's pixels to actual LEGO colors? except that I need to fit a certain number of bricks of a certain colour.
For example, I have 20 white, 28 yellow, 10 orange, 18 red and 24 black (colours listed in increasing darkness) 1x1 bricks and a greyscale 10x10 pixel photo. How can I manipulate the photo so that it shows the 20 brightest pixels in white, next 28 in yellow and so on until the darkest 24 in black? If there is a tie, for example, the 19th, 20th and 21st brightest pixel have the same brightness, it highlights the ties and tells me that two of them should be white and one should be yellow.
Bonus: The above uses a 1-dimensional algorithm, but how can I have a 2-dimensional (or more one)? For example, if I have 10 white, 20 yellow, 30 blue and 40 black 1x1 bricks, and an image with shades of yellow, green and blue, the program should assign the most yellowish greens to yellow bricks (or white/black for brightest/darkest ones) and bluish greens to blue bricks (or white/black for brightest/darkest ones).

In case anyone familiar with JavaScript is interested, I wrote this script (tested in Firefox 19) which lets the user specify the number of tiles (bricks) of each colour and browse for an image file with the same number of pixels.
The luma (brightness) of each pixel is ranked and assigned one of the listed colours. Any ties are arbitrarily assigned to either possible colour (as JavaScript's sort is unstable).
http://upload.wikimedia.org/wikipedia/commons/thumb/5/55/Mona_Lisa_headcrop.jpg/20px-Mona_Lisa_headcrop.jpg  is an image which fits the example tile count.

 <title>Make mosaic given tile colour count</title>
 <form onSubmit="return false;">
  <textarea id="counts" rows="3" cols="80">// Ordered from darkest to lightest
colours = [ '#000000', '#993300', '#cc0000', '#ff9900', '#ffff00', '#ffffff' ];
tiles   = [       110,        40,        80,        60,       120,        90 ];
tileWidth = tileHeight = 16;</textarea>

  <input type="file" id="file" size="80" />

  <input type="button" value="Go!" onClick="loadImage()" />

  <canvas id="canvas" style="background:#808080;border:2px groove;"></canvas>

 </form>


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Easy way to get the weight of a Bricklink order
Is there an easy way to estimate, to the nearest 100 g (or so) the weight of a shopping cart in Bricklink so that I can estimate the shipping charge (sellers may quote ranges such as "250 - 500 g: $X, 500 - 1000 g: $Y" so I wish to stay in a cheaper band if possible)?
I can find out the weight of a type of brick (such as this) but summing by hand is a chore. Just wondering as it already has all the necessary info...

Click on the MyBrickLink tab on the top row, then My Settings in the second row of tabs, then the My Shopping Settings link. Check the box next to "Show Weight in Shopping Cart". Then, when you view a cart full of items in a particular BrickLink store, scroll to the bottom and it should tell you the calculated total weight.

http://www.bricklink.com/storeSettings.asp?viewFrom=P is a direct link.

Not only that, it shows the weight of each part (brick type) — brilliant, thanks :-)

Remember to allow for packaging materials; 30% of the weight is a rule-of-thumb some people use.


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Why was the 1x1 round brick changed?
The first 1x1 round bricks had no lip, just like most bricks:
Brick, Round 1 x 1 Old - No Bottom Lip

A lip was then added:
Brick, Round 1 x 1 Solid Stud

Why?
Later, a hole was added in the stud:
Brick, Round 1 x 1 Open Stud

Was that to prevent choking, as in some minifig heads?

The full-base 1x1 round bricks were produced from 1955 until 1963, during the period when LEGO pieces were made from cellulose acetate (CA) plastic, but were sold until about 1966. According to Gary Istok's Unofficial LEGO Sets/Parts Collector's Guide the solid-stud full-base 1x1 round brick was only ever made from CA plastic. After the supply of them ran out, a new design was adopted with the "tapered" bottom and made from ABS plastic. (Chapter 51, p. 3)
The reason for the change may have had something to do with the fact that the old full-bottom bricks did not grip very well. Also, the tapered-bottom bricks not only fit over a regular stud but fit in between top studs, making them more versatile than the older style.
The hole in the stud appeared about 1977 and was in response to product-safety regulations. Other cylindrical pieces like minifig heads were also given stud holes. This was because it was thought cylindrical pieces were more likely to completely plug a nostril or throat. The solid-stud minifig head has made a comeback recently, however, as these regulations have changed.

Thanks, that's very informative, but why would having a lip improve grip compared to full-bottom bricks ("The reason for the change may have had something to do with the fact that the old full-bottom bricks did not grip very well.")?

The poor gripping power may have been what prompted them to look for a new design is what I meant, and during that process they decided to make the bottom of the 1x1 round more like the standard tube on the bottom of most bricks. It may also have been the switch to ABS plastic that prompted the design change. The trend in piece design in the 60s and 70s was to add functionality and increase the gripping strength - adding slots in the round corners, changing the 1x1 round base, adding tubes to hollow bricks, getting rid of the "waffle bottom" plates, etc.


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How to remove printed decoration
This is probably heresy, but how can I remove the printed decoration on a brick? I managed to buy a large number of bricks with an eye decoration cheap and found that rubbing a long time with isopropanol removed the decoration but also scratched the surface. Is there a readily-available solvent that can dissolve decorations without needing rubbing, or otherwise damaging the brick?

Brasso (yes, the metal polish) works wonders as far as removing print. Yes, you still have to rub it, but it won't damage or scratch the surface and it works fast. Just use a soft cloth, pour some Brasso on it and wipe away the print.
Also, pure Eucalyptus Oil works really well. It requires a bit of soaking, but it will remove the print wonderfully and it smells good to - unlike Brasso. Saturate a piece of cotton in Eucalyptus Oil, place it on the printed surface, let it sit for a few minutes, then wipe away the print. It may require a bit of rubbing too, but usually not much.
Hope this helps!...(c;

I tried Eucalyptus Oil a found on some figures it worked very slowly and took a lot of rubbing, while on other figures it worked on very quickly.
I don't know what the difference in the figures paint/decal is or could be.
I did find that Ethyl Alcohol (not Isopropyl, have not tested yet) worked fairly quickly with aggressive rubbing with a q-tip swab.
I also notice in some cases there was a slight "ghost" impression left behind.  Likely the new decal or paint would cover that though.

I got good results using Soft Scrub with Bleach, an old towel, a Scotch-Brite scrubber sponge (the green and yellow one), a bottle brush, and a pile of Q-tips.
Put a dollop of Soft Scrub on an old towel, dip the Lego piece in the cleanser, and rub 30-60 seconds on the scrubber side of the sponge. Check for results and keep rubbing until decoration is gone. Rinse well.
If there is a lot of residue buildup inside the piece or stubborn paint after rubbing, use the bottle brush and Q-tips for cleanup and detail work.
I had 60 pieces from which to remove the paint. The above method took me 1-2 minutes per piece vs. Brasso, which took about 5-6 minutes per piece.
Hand cramps are the mother of invention, I guess?

I used tea tree oil, it worked but tended to leve a ghost and if removed that would impair the plastics ability to reflect sunlight.


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Why does the pin recess on the Technic turntable continue to the edge of the part?
Here's the part in question (2955):

While Technic parts typically have a recess to allow the ends of pins to be flush with the surface, this part (and perhaps others) carry this recess all the way to the edge of the part in a U shape.
I looked through instructions from a few sets to see if I could figure out if there was any utility to this, but I wasn't able to find anything. Here's an example of the part used in the Mobile Crane (8460):

Is the some purpose to this design, or is this just a quirk of this part?

Seeing how LEGO parts are injection molded, I'd say it's because the mold has to be moved away from the part without damaging it. So if the recess weren't there, the mold would just plow through the part in question.

As suggested by bumbumfish, it is indeed required by the molding process to be able to remove the part from the mold. This does exist in many other parts, such as Technic frames:

The alternative is a mold with moving parts, but this is more expensive, and can't be used anyway where there is not enough room for the mechanism (e.g. inside frames).

Another good (if maybe more subtle) example of this is the pin joiner which now has a slot in the middle. That slot is similar to the recess seen in the other parts, in that it simplifies the moulding process greatly. (The previous version required two sub-parts to be assembled together, which is even worse than a mould with moving parts)


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Best sensor for balancing inverted pendulum
I want to build a balancer for an inverted pendulum. Which of the following sensors is best suited for detecting the tilt?

Accelerometer
Gyroscope
Angle sensor

As you say yourself, you want to detect the tilt of the pendulum rod, so I'm assuming what you're after is actually its angle. Measuring anything else would probably result in tedious calculations anyway; and in addition, considering you'll want to try to keep the angle in a specific range, you'll need to know it.
As such, an angle sensor may seems the most logical choice; but a gyroscopic sensor will not only offer you the angle, but some indication of the current rotation speed as well, which will be useful if you want to mimic the behaviour of a servomechanism.
However, these two sensors are single-axis only, which means that if you want the rod to be able to swing in more than one dimension, you'll have to use one sensor per axis, which may prove cumbersome to build. In that case, the acceleration sensor is probably better.
All in all, all 3 sensors are probably usable somehow, but it really depends on what exactly it is you want to build, and what you've tried so far. I'd also recommend searching for similar projects; for example, there are numerous NXT "segway" robots out there, and there's a detailed tutorial on how to build one with a gyroscopic sensor. Note that the feat seems to be possible even using a simple color sensor to detect ground proximity instead of knowing the exact angle.

Check out the dIMU sensor which provides both accelerometer and gyroscope for all three axises in one sensor. It doesn't have a nice casing though.

dIMU Inertial Motion Sensor link


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Options for sorting old and new versions of colors
I'm working on sorting my LEGO collection. I'm sorting by part then color, with colors mixed when it makes sense (e.g. black is separated out, but medium blue and dark red are together). I'm trying to figure out what to do with similar colors, and I'm curious what most AFOLs do with them. These are the colors that I'm trying to figure out:

Light Grey / Light Bluish Grey
Dark Grey / Dark Bluish Grey
Brown / Reddish Brown

I know that some people just put the similar colors together, but I find that I usually don't like how they look together in a build. I also don't think that my collection is large enough at this point to justify separating all six of those colors out separately.

Or you could just sell all old greys/browns to some fanatic.

I too think you answered yourself partially.
You don't want 6 separate containers for these colors, which seems sensible; but on the other hand you admit yourself you mix some other colors when they are easily distinguished. Which I fully agree on: the first sort you should make is by part type anyway, and only afterward, if you have too much of a part, you may want to split the heap by colors - but not necessarily all colors, since your goal there is just to split a big heap to keep it manageable.
So how do you decide which colors to put together? Again, you hinted at it yourself: colors that are too similar are best separated. So you'll for example have a container with black, yellow and red parts (guess which country I'm from ;-)), and another with dark blue, orange and white.
Another possible option is if there is one color which is predominant: if I have, for example, 1000 1x2 blue bricks, while I have only 500 of 1x2 bricks of all other colors combined, then maybe setting the blue apart make sense. And even then, the best is probably to set 900-950 aside, even in a ziploc bag, and put the remainder with the other colors. The ziplog bag will probably stay unopened until I get a project which requires a massive amount of 1x2 blue bricks. (Actually, it's a real example, I did exactly that, and ended up using the blues for a smooth river)
So what does this leave you with the old/new color issue? Simple: you make two containers, labeled "old" (with Light Grey, Dark Grey, and Brown) and "new" (Light Bluish Grey, Dark Bluish Grey, Reddish Brown). That way, you have no problem knowing if it's old or new, and mixing these three colors shouldn't be a problem.

Seems like you've answered your own question (for now) by saying that you don't think your collection is big enough to justify such sorting.
On the other hand, one might suppose that your collection will eventually get to that size, at which point, you'll have to decide if you need to separate them for storage, or if sorting while building is 'good enough'. They are certainly easy enough to discriminate when side by side...

I'm going through the sorting process right now and I've gone with the following compromise:

Old light grey and new light grey are sorted separately because they are hard to distinguish at times, yet clearly different most of the time.
Old dark grey and new dark grey go together, because I don't have enough of either to justify a separate box, and they are easy to tell apart under just about any lighting.
Old brown and new brown go together, because I have a hard time telling them apart in just about any lighting except full sun. I will re-visit this decision later if it turns out to be a problem.

Don't forget to leave room in the boxes for the new colours to grow. The old colours probably won't grow, so Joubarc's suggestion to sort all old together and all new together is a good compromise too.


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Ultrasonic problems with the red and blue balls?
I'm still new to NXT, I try to make the robot locate a ball using the ultrasonic sensor, while there I should be in a square area marked by white color.
How can I make the robot locate the object (by ultrasonic), stop, get the distance, then move until it stops exactly in contact with the object?
Here is my project

The ultrasonic cannot detect the color of objects. It's just to detect the distance between the sensor and an object in it's line of sight.
To find objects in the surrounding area of your robot you have to look all around. This is simply done by rotating your robot or your sensor. When you measure a distance in a certain range (best results between aprox. 10-50cm) you can stop rotating and you have your direction. Then you start to move and check for better results every 10cm or something like that again if you are still facing the right way.
Stoping exactly in contact won't be possible unless you can say I am Xcm away and now can move exactly Xcm in this direction since the ultrasonic sensor cannot measure distances below a certain level (around 5-10cm depending on the size/shape/material of your object).

Regarding the white square on the ground, the robot can not sense this using the ultrasonic sensor. This is because the ultrasonic sensor uses echolocation to navigate (hence the name "ultrasonic") If there is a white square on the ground such as a piece of paper which is essentially 2 dimensional, the sensor will not 'notice' the square. Try another method, perhaps using a 3 dimensional object, and a color sensor while you're at it.


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RCX 1.0 downloaded firmware successfully with RIS 2.0 but does not run any program
I have installed correctly the RIS 2.0 in an old laptop running Windows XP and I successfully downloaded the firmware through the RIS 2.0 to the RCX 1.0, following the standard setup instructions.
Now when I turn on my RCX 1.0, the display shows the full function mode. I can also change the activated sensor port and the outputs pressing the View button. Yet, the Prgm and Run button do nothing.
I cannot change or run any program. It stays in program 1, which does not run when I press the run button.
I would appreciate any help please.

This sounds like it could be a hardware problem. Do you by any chance have access to a RCX remote (or NXT with IRLink) to see if you can run programs that way? Can you actually download programs without trouble? (I'm not sure anymore if the standard RIS interface allows to start a program remotely, but if it does, you should try it too)

Are you sure rcx 1.0 works with firmware 2.0?

Simple solution: ensure that the RCX is connected to your computer and that they are both updated to the latest version. if this doesn't work, downgrade the firmware to the previous versions if you already had the RCX before updating.


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Strongest gear configuration
I'm building a (what I hope to be) high-speed car using two PF-XL motors together and some gearing up. However, there's a point where I have to rotate the axle with power (that comes from the 3 speed gearbox) 90 degrees to line it with the wheels (this is probably a long way around the barn to say it in english, but I got a picture to fill my lack of words). This is what I want to do:

(the position of the gears is incorrect: in my project the 8t gear would be one hole to the left)
My question is, assuming the structure holding the wheels is solid and won't bulge, what's the best gears to use so that they won't snap?
So far I've considered four combinations:

The same as the image, except the 8t is a 16t
The fat 20t with the fat 12t
The skinny 20t with the skinny 12t (this one doesn't actually work for me unless I do some changes to the car)
Two of those 4t gears that aren't very smooth

It stands to reason that the last option is the strongest because they don't snap unless they break apart. However, they're more suited to low speeds. With high speeds they aren't fluid at all and make a lot of noise. But my biggest problem with them is that they sometimes get stuck (the gear without power sometimes stops in a position where it blocks the gear with power and when the motors start again they can't rotate - this is really bugging me).
So, excluding the last option, what do you think?

This question would be easier to answer if the application was made clear.  Are the axle locations in the picture (edit accounted for) in a fixed location, aka have to be there?  Are you wanting a gear reduction or a 1:1 transfer?  Is there a height restriction that would prevent larger gears from being used?  Is a differential used in the solution an option?  Do you have any restrictions on what gears you have access to? If a gear reduction is desired, which axle in the input?

I would tend to recommend some options which you didn't consider yet: using bevel gears, but actually use a combination of two gear on each axle: a 12t one (the thin one, as you say), and behind it, a 20t one (there you can use a fat one, which will probably be better).
Another option is to use a worm screw, which will also allow you to change the direction of the axle, but which makes the axles non coplanar.
But it really depends on a variety of factors. Gear reduction is one (keeping in mind it has implications on torque, but frankly I'm already way over my head here so I won't tackle that aspect); but torque transmission is another, and so is strength/reliability.
For example, the knob wheel that you did mention has some uses, as it practically can't slip, but at the cost of lower torque transmitted (or something). Worm screws again have another particularity which is unique to them in that they can transfer torque only one way, which also has its uses (locking a mechanism in place).
And then don't forget that the gears aren't all there is to say: sticking your gears closer to the beams will help, as will replacing the two separate beams by an actual frame. You can also make sure one of the axles goes all the way to the other side of the frame.
And last thing, if you're going to transfer power to two wheels, don't forget to use a differential between them (not sure the new one is very solid though).

Thanks. You mean on one axle use those two gears, but what about the other axle? What gears would you recommend? Also, worm screws aren't really what I'm looking for, as they reduce speed dramatically. And I have already added a differential (the old one, since I only have of that type).

I meant, use both gears on both axles, for a total of 4 gears


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How hard is it to get a job within the LEGO company, straight out of university as a graduate?
How hard is it to get a job at the LEGO company?
Being fresh out of university as a graduate of mathematics, I'm specifically interested in answers on if and how LEGO hires graduates.

See also the question How does one get a job as a LEGO designer?

LEGO has a list of open positions which you can consult. As far as I understand, the application process starts there and you have to register a profile to apply for positions. Some positions also list a direct point of contact who can answer questions on the specific position (usually the boss-to-be, I suppose).
I'm not sure where a mathematics background might be useful within LEGO, but I don't know the full organization by far, and there are certainly some positions where it's going to be useful. In any case, don't be too afraid by all requirements listed for given positions, they don't necessarily mean that someone isn't suited for the job. But that's probably a discussion for another site.
Of course, jobs for which experience is required will probably be out of your reach, unless you do have experience in the required domain. For example, you could very well be a good LEGO builder already and have a chance for a design job.
But the good news is that LEGO seems to be willing to attract young talents, in particular in the IT sector. I remember seeing recently a "job position" which was in fact some sort of one-day seminar for young graduates, so that they could see what the life at LEGO is. There are also open positions which specifically mention students.
In any case, enthusiasm about the LEGO brand is certainly useful, and of course you'll probably have to devote some thinking time about where you're willing to work and live, especially considering most central positions are in specific countries, with Denmark being the most important.


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

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

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

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

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

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

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

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

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


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How to make custom LEGO signs, newspapers, etc.
I have several ideas, but I am finding it hard to get started. What I am interested in is making my own decals for signs, newspapers, artwork for the walls and others. So far I haven't had any luck.  Is there a site that has LEGO clip art backgrounds, lettering, etc.?

BrickLink has a huge collection of sticker sheets which can be used for inspiration. My answer from a previous question explains how you can obtain decals from existing sticker sheets.

Your question is vague. Are you having difficulty with inspiration, artwork, printing or something else? What do you want "LEGO clipart backgrounds" for, and what do you think they are?

Well I don't exactly know what you mean buy a sign like one that he/her can hold or a sign in the ground? Moving onto the newspaper you can get white sticky clay and get two white 6x5 pieces or a size you like and fill in the crack in the middle then put one piece of clay in the Lego persons hand and shape it in a Lego rectangle size
 Hope this helped


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Setting priorities in LEGO NXT Programmer
For a sumo bot competition I made a robot that has a perfectly functioning ultrasonic senor. However, when I made a second branch on the program for a light sensor, I calibrated the light sensor and when I set it over the line so the robot would move correctly, it does not respond as expected.
My thoughts are that it has to do something with the priorities of the branches. How do I set the light sensor branch to have a higher priority over the ultrasonic sensor branch? I would like it to work so that when the light sensor doesn't detect something in the specified range of intensity that it goes to the ultrasonic sensor branch and go to the light sensor branch if an intensity inside the specified range it goes to the light sensor branch at a high frequency of resolution.

Can you please post a screenshot of your current program?

Branches run simultaneously. If you want to pause a branch until a certain sensor condition is met, use a Wait block.