Hrafn

If the 3L worm gear (15457) is placed parallel with and 1 stud above the 7L gear rack (87761), will the gear and rack mesh? Thanks!

Thanks, everyone. For my application space is at a premium and I need to keep everything in this part of the construction at integer-stud spacing, so the 3L worm won't work. I have other options fortunately.

Victor, Take a look at this shifter (not my design) with six positions separated by 60 degrees:

You might be able to adapt this one from DurianObried - it's a definite shifter with 6 positions: I've built it and it works very well. Piterx built some 4-position shifters using a shift drum:

I've been trying to build a 1:10, rear-wheel-drive rally car and am running into a number of problems. Right now the issues are with the front suspension and steering. I had hoped to have 1) short long arms suspension (for progressive camber with suspension travel) 2) some caster angle (to help with bump steer) 3) Ackerman steering (or close to it); here I'm using a three-piece tie rod [EDIT: adding a bit of longitudinal reinforcement fixed a lot of this, but I'd still like to hear what people think of the setup and if they have any suggestions] However, I'm having three two problems: 1) SLA suspension plus caster leads to terrible toe-in and -out with suspension travel 2) The tie rods are behind the wheels, and there is way too much play in the system (and some toe-out when moving forward). Some of this I know is due to my not having fully reinforced the steering rack assembly, but I'm not sure more reinforcement will totally fix it. Basically, the two-stud-wide rack assembly wiggles forward and backward a lot when you push on the wheels. 3) With aligned and equal-length wishbones, I get near-Ackerman performance; with this setup I no longer seem to. The wheelbase is 30 studs, and the current (tentative) design is below. Top (with the motor towards the front of the vehicle) Bottom (note that the 6L arms are offset .5 studs from the top arms): Any advice would be much appreciated. Or if you can think of other people's MOCs I should look at for inspiration, let me know. Thank you!

Gorgeous and very impressive! I love the shot you have on your Flickr photostream of this with all the other minifig-scale functional vehicles you've built.

It could simply be that they were made in one batch, and the red for that batch was slightly off. Red isn't as bad as yellow or dark red in terms of inconsistent color, but there certainly is some variation in red parts.

I have 3, all different colors (yellow, orange, and black) and they are all very stiff.

As far as I can tell, neither that nor any of the other "Torsen" diffs made of Lego are actually proper Torsen diffs. They don't sense torque; instead the diff locks when the the angular position of the two shafts differs by enough. They only unlock if that angular difference is reduced. In other words, there is no torque bias because this is a locking, not a limited-slip, differential; and the locking is based on relative angular position, not angular speed or torque. True mechanical torque-sensing differentials seem to require helical gears, which Lego does not make. There are simple ways of making limited-slip differentials with rubber bands connecting the half-shafts to a common third shaft, and those work reasonably well at low torque.

Beautiful! I'm not normally a big fan of either Lamborghinis or this style of bodywork in Lego, but somehow it just looks right. The yellow and black color scheme and the sleek curves make it look very swift and aggressive.

True centerpoint steering can also be done at larger scales by using thin wheels, custom hubs, and some steering axis inclination (SAI, aka kingpin inclination). My Lancia 037 had near-center-point steering using 62.4x20 wheels, custom hubs, and Short/Long Arm (SLA) suspension (5 studs on the top, 6 on the bottom) to give some SAI. My current project is about ~14 studs wide and has center point steering or close to it (the theoretical scrub radius is about negative 1mm) using a MacPherson setup.

Thanks, that's very helpful!

I'm working on a small (1:14 or so, 14-15 studs wide) car and want to include some caster angle in the front (MacPherson) suspension. Most real cars seem to use angles under 10 degrees, but what works well in motorized Lego vehicles? Should I exaggerate the caster in hopes of improving the steering's return-to-center tendencies? Even the smallest angle that's easy to achieve with Lego (22.5 degrees) seems a bit excessive compared to real cars. Also, I'm hoping to build the front suspension and steering into a subframe that will be tilted relative to the main chassis. Does anyone have any advice on doing so, or examples they could point me to? It seems like the way to go, since it makes it easier to correctly position the steering rack. Previously I built an SLA suspension and just offset the A-arms longitudinally; that was compact but made steering a pain.

At 12 wide you'll want fairly small parts for those curves. Part 11477 is available in yellow, as are some of the other curved slopes

The abundance of black parts in sets does seem like the most likely cause. I prefer to use black only for areas I'm trying to draw the eye away from (like the chassis of a car) or for decorative details on a brightly colored MOC. Very few all black models look good to me, though that might be because the color is so hard to photograph well.

For me, stacked beams look good only if they meet the following criteria: 1) they are representing a flat area (or a faceted area, if bent liftarms are used) 2) the beams are all or mostly the same length The first echoes what bonox said - if the area being modeled isn't flat, it often looks better to suggest it and leave some gaps than to fill it in with the wrong shape. The second may just be a quirk of mine, but it drives me crazy to see a solid wall of liftarms with dents in it where one liftarm ends and the next begins.

The last one in particular seems like it should be useful, but I've yet to find a good place for it. Seconded!

Interesting! I wonder why, since RWD is the normal setup for real-world drift cars (monstrosities like Ken Block's Hoonicorn, and 4-wheel drifts during rallies, notwithstanding).

Interesting. I really like the solution you have found of making the rear wheels spin faster. Have you tried making the car RWD only? While in real life there are some all-wheel-drive drift cars, mostly they're RWD.

When you say deleting the front diff, do you mean making it rear wheel drive only, or powering the front wheels at the same speed as each other?

Interesting! Those both sound useful.

Nice! I hadn't thought of using it in that application.

Those paddle shifters are brilliant!

Excellent work! Thank you for sharing it and putting together a CAD file!

Has anyone found a good use for "Hero Factory Weapon Barrel with 2 Pin Holes and 3 Axle Holes" ? I got a few on BL with the vague thought that they might be useful in orbital transmissions.