Hrafn

He probably means a micromotor. They are very slow but have decent torque for their size.

Sariel's book helped me a lot when I came back to Technic and had to adapt to studless; he talks in the book about the strengths and weaknesses of each and how to combine them. It is a steep learning curve, but worth it since studless opens so many possibilities and can be used to build so compactly. A lot of studded parts are still quite useful even if you move to building mostly studless - the 4L differential works nicely as a longitudinal central diff, the studded beams can be used to stiffen up a frame, etc.

I agree. Maybe the new part was designed to solve some other problem that couldn't be solved with existing parts, and then they used the part in the snowmobile because it was available? Maybe we'll see the part in a 2H 2014 model in a context where it makes more sense.

22 years old! Wow. He says he's around machinery a lot at work; I wonder if he's in engineering or manufacturing? Certainly he's got the skills to make a living off of mechanical design if that's what he wants to do.

I have intentionally not bought any of the 5L xooox thin liftarms because I know that as soon as I get a few, I'll find them indispensable and have to spend way too much money on Bricklink building up a stash.

Just a quick question - is the diameter of the spherical core of the Shadow Leech part the same as the technic ball joint, i.e. 10.2 mm? Thanks!

It does answer my question, thank you. I'm not planning on using it for a structural connection; instead I want to use it to create friction between two other parts. The full details are in my continuously variable transmission thread, if you are interested; I'd be using the leech to replace the ball joints in that construction. I will probably have to modify the leech by cutting off the parts that protrude from the sphere, though. Thanks again!

Thank you! As long as it's approximately the same size as the ball joints, it should work for what I want to do.

Ah, I see what you mean now. It's true, having more sizes of gears would allow more combinations of gears at each spacing. Here's hoping we get a 28t double bevel at some point, at least!

It's yellow at a meshing distance of 2.968 studs, but green 9 rows down at a distance of 3.000 studs. The rule of thumb I outlined should work for the optimum spacing for any Lego gears (other than the worm) since it's based on the facts that 1) for teeth to mesh, they must be the same size and 2) the number of teeth is proportional to the circumference of the gear, which is also proportional to the radius of the gear. Of course the rule of thumb doesn't tell you anything about non-optimal spacings that still work reasonably well (with some slop or friction).

I agree with you about size - even 24t can be large in gearboxes. Spacing, though, should be somewhat less of an issue. We already have gear combinations that don't work with an integer number of Lego units (L) - 8t and 20t, for example. The axle spacing (in mm) required for perfect meshing of two gears is equal to the average of the number of teeth on the two gears. So two 8t gears have an average of 8 teeth and need a spacing of 8mm (which equals 1L). The 28t would mesh easily with the 20t (3L spacing) and the 32t with the 16t (3L). The latter isn't very useful, though - if you need a 2:1 ratio using a 16t/8t is much more compact. On both size and meshing, 28t seems more useful than 32t.

Good topic! In addition, I believe the large Technic turntable has 56 teeth, and of course there are the old, weak 14t single-bevel gears. 1. 28/32 tooth gears wouldn't add much utility, since they wouldn't be that different from 24 and 36 in terms of the ratios you could achieve with other gears. I do wish the 3L differentials had the same number of teeth as existing gears, though - currently they have 28 which can be awkward. 4. As has been brought up in other threads, clutch gears in sizes other than 16t would be nice, probably 20t and 24t. It would be hard to make 8t and 12t work, and 36 and 40 would be too large. The "dogbone" liftarm in the 2014 sets looks promising. I'd like to see more liftarms with holes in more than one direction, like the 5x7 and 5x11 but smaller.

That would be awesome, but where would they get all the RC motors? Those things are expensive secondhand.

So you have one channel for driving, and one for steering? Are you trying to get Ackerman steering in the normal mode? That will make it more difficult to also do crab steering.

I love the idea, it's very different from the usual things people build with Technic. It's impressive you managed to make it as an alternate build of an official set, too!

Very nice! I'm impressed you could fit all that in to the base of the vehicle. As for the lights, all the ones I've seen in recent years do have both red and amber lights, never just red.

The second one is more accurate, but I like the first one better. Somehow it seems more like an archetypical school bus than the second one. Both are great, though! They're a really nice mix of accuracy and classic (slightly cartoony) Lego minifig scale style.

Interesting. That doesn't seem to be an issue in hydraulics like those in many construction vehicles - is it an issue in pneumatics because the air is compressible while liquids are essentially incompressible? If Lego made a proportional pneumatic controller (especially one that connected to the PF system!) I think it would still be a valuable addition, even if it wasn't all that precise and the motion depended not only on the controller's setting but also the load on the cylinder. Any proportional control would be nice to have, even if imperfect.

It seems like it would have a problem with getting "jammed" on tall obstacles, too, instead of rolling over them the way a normally oriented trailing arm suspension would. It looks cool, though, and that is the key criterion for games!

I have not, but the issues that come up with non-motorized linkages will also be a problem with motorized ones. In particular, some linkages suffer from 'slop' - the small tolerances in Lego joints and the flexibility of each piece can add up to make the whole mechanism more 'floppy' than expected. The scissor lift in particular seems to suffer from this problem, since it has so many moving parts.

Some train wheels can be attached to Technic axles, so if you had some of those you could build your own cars to solve both of the problems you mentioned.

Thanks! The robot arm to grab the chain is clever, I wouldn't have thought of that.

I used Bricksmith, which is based on LDraw. I kludged it together since I don't actually know the software, so parts don't quite connect properly, but it's close enough for an illustration of a small assembly. I'd be very interested in seeing more photos of the car - it's nice and small but hugs the rails very nicely.

Like this? What parts did you use in the car?

Actually, there is a way to do that, at least partway. If you're looking for things in your Wanted list(s), you can go to the Wanted tab and the Settings sub-tab to set what countries to look in. BL's interface is a mess, though, with settings pages scattered everywhere and terrible search options. I hope the new owner will really revamp things.