DrJB

Waow!!! Did you read my earlier posts 'defending' him? Or you simply skimmed through and reached your OWN 'superficial' assumptions? Let's not be personal here, he put a lot of work (JB-weld thread) to fool us and many of us fell for it. In my book, he succeeded! He did admit himself this was a joke (april's fool), and I do find that very original! Yes, as an educated man, I find it very unlikely (tempted to say impossible, but do not want to alienate those without a physics background) that we'll ever see perpetual motion, but I won't stop in any one's way trying to prove me wrong. This thread is NOT about what I think, this is about having fun with Lego And, getting back to our fun topic, here is something I found. It is not about perpetual motion, but something a bit closer to that. It's a camera that is self-powered. In one cycle CMOS works as energy harvesting (solar cell), and in another cycle, the CMOS takes the picture. If you take the camera by itself, it appears to be a perpetual machine ... unless you try to take pictures at night where there is no light in sight. Incidentally, this point was already brought up by a prior post i.e., make sure to account for the boundary conditions (power supply) correctly. http://www.techbrief...news/news/21957

In principle, one can put the 'program' on a band (track elements) and have the display run messages one character at a time. I know, easier said than done of course.

Jim, Somehow many of your frontpages do not last long. You're doing a fantastic job highlighting these novel MOCs, but somehow there is always someone from a different subforum that brings something else up. Is there a way to 'force' frontpages to last a given/minimum number of days?

I can already guess what we'll see next year, around this same time: A lego Time Machine, with Linear actuators, long pneumatics, and maybe one EV3-II

I somehow missed this, but the option to program from Matlab definitely opens up the opportunities dramatically. Great find, thank you!

My last official fire truck pales in comparison to this masterpiece ... :(

Well, i was speaking of the 'masses' aka the large majority of tires/wheels out there. I spent enough of my years working in the tire industry and know that from 1st hand. Yes, high performance cars have 'directional' tires that cannot be rotated. They are however rather pricey not just to buy but also to replace. I personally think we will never see directional tires/ wheels made by TLG because it is simply too complicated, from many aspects. When you think about it, the various balloon tires were inspired from agricultural tires that typically have an alternated chevron pattern. However, doing this in lego would complicate mold geometry, demolding, ... etc. Now, and back to real tires, and I have designed/optimized patterns myself, the modern tires care not about symmetry of the pattern. In other words, the pattern needs not be symmetric visually, but performance wise needs to be symmetric whether the tire is spinning one way or another (to enable tire rotation, for wear). In fact, modern tires have ribs dedicated each more or less for the various tire performances (cornering, wet handling, snow traction, ...) We should ask efferman if he can do directional/nonsymmetric tires/wheels from 3d printing. Heck, why stop there, we should do square tires as well ... ;) They say the shoes make the suit, I'm guessing in your case the wheels/tires make the car stand :)

Just a thought: to minimize friction, the gyro has to have perfectly axis-symmetric inertia. Thus, it might help to dummy gears along the whole circumference of the 3 rings. that is only in principle as, in real life, it is a bit difficult to estimate and account for friction.

Looks like the pictures from OP are from LDD and it's simple enough (it seems) that one can do this in 15 mins or less. Or am I missing something? Well, I just tried to do an LXF over my lunch break and Flickr decided to go off-line. :(

Rather novel. Reminds me of a graduate course in advanced dynamics many years ago, and gyroscopic/rotordynamics was the high point. Can you spin it fast enough to get so called 'gyroscopic effect', where the axis of rotation tries to always point in the same direction? At first, it looks like a gimbal suspension of a gyro only, but if it spins fast enough, this may change.

Simply Outstanding! Hall of Fame? Reminds me of some posters at work. Is the original made by Iveco?

Very well done. I especially like how you used the servo to switch functions!

NPU = Numeric Processing Unit ?

Seems obvious, but I have to ask: You have 1200+ balls or ... many of them went through several times?

Four rings to rule them all ... Isn't the ring simply used as a half-width spacer?

My understanding is that you can use it to connect the old sensors/motors (RCX brick) to the NXT brick.

Seems I'm reading the Enquirer or some other tabloid. Just one word: Really?

There is high demand for such part as it's used in many notorious MOCs Next time you're out driving, make sure you pay close attention as all such fancy wheels have a single profile, they do not make them for left/right sides of a car separately. Or else you won't be able to rotate your tires (for uniform wear). Well you could, but you'd have to disassemble tries/wheels everytime and not sure everyone is willing to go through that trouble. Many people like those wheels because they have realistic wheel offset geometry. This is important for vehicle handling, return-to-center steering and so on. This was debated many times and the problem is that, if you introduce such Technic Figures, then all technic sets need to be to the same scale. That is hardly achievable today. The technic tank is still available, though in white only. Check your local lego.edu Good find. Did they update the building instructions after the recall?

I looked in the online instructions of both models (online) and could not find where it is used. I also do have model A displayed and could not find it. We need a larger audience to take part in this endeavor.

I did an LXF file from the instructions (check other thread). Of course LDD's no collision constraints were at times problematic as they won't allow even small collisions but nonetheless.

Is it yellow or tan (light nougat in LDD)?

I should have been more careful and said 'offer limited options' instead of 'offer no option'. That said, and because the spacing between the top/bottom towballs is small ( 2 studs), any fore-aft offset of either would cause relatively large caster angles. The hubs from 4200 have larger spacing between top/bottom towballs and as such enable one to reproduce small (more realistic) caster angles. As for king pin axis, I still stand by my original statement that in such elements, any kingpin attempt would result in the actual wheel/tire being totally tilted and are thus not feasible.

+1 Agreed that a full suspension is more fun/challenging. If you're feeling 'adventurous', how about some air-springs?

What, no one likes this model? Or it is so 'old generation' and you're all spring chicken? :laugh:

Thank you, together with Balkbird's Ldraw, your LDD is a commendable effort. One now has NO excuse for not building this masterpiece. If you're building this in girl's colors, I would definitely love to see pics once you're done. +1 What I like most about Blakbird's 'version' of the story is that he broke it up into two sets of parts moving: the balls AND the buckets. You could spend hours watching them go round and round, and never 'catch' that detail. Looks like Blakbird's skills go beyond povray/renders. Story telling is sure right up there.