A concept i’ve been working on, it’s a trial crawler with a two speed gearbox that lets it go trophy truck fast and crawler slow. Remote shifted by mini LA. 2 buggy motors for drive, an m motor for steering. pictures:
And the video:
Instructions for my rock crawler 4wd/4ws are up! The LDD file should have everything in it, it just needs you then to insert Battery Box and attach the suspension linkages.
World first! I modified slightly my earlier design for an automatic transmission so it could work well in a trial truck. I had to change around some of the gears and supports so that it wouldn’t slip in first or second gear. I also changed the gear-shift mechanism so that it is all lego, no rubber band but instead a spring. It works very well, downshifts going over an obstacle for more torque, then upshifts again for speed when over the obstacle. The trial truck is a quite simple design, it uses my axles from rock crawler project and 3 link flexible live axle suspension. XL motor for power, m with worm gear reduction for steering. Video:
I replaced the rear axle on my lego rock crawler with a steerable axle, creating a 4WS crawler. Performance is great, the turning radius is exceptional. Video:
The final version of my automatic gearbox, this time using a mechanical “torque sensor” to shift a pneumatic valve, thus changing gears to a lower ratio, giving it more torque for an obstacle. Then, when the resistance on the output shaft lowers, the valve changes directions again, switching the gear back to high speed. Ratios are 1:1 for high speed and 9:25 for the low speed. Video:
A simple two speed gearbox shifted by two mini pneumatic pistons. Its gear ratios are 5:3 and 3:5. Very robusta nd durable, great for trial truck. Video: