Retun-to-centrer systems are very useful and important for some MOCs and almost essential for making RC cars.
But sometimes it is difficult to find a simple, reliable and effective system, so I show you some possible solutions to this problem.
The most simple and used system is using a specific piece, but hard to find(x928cx1)
Build like this:
It is impossible to build a simpler system. But it has a couple of problems: you can not regulate the center force and it is not very accurate.
For these problems I do not like to use that piece, and have developed some systems using only common parts, very simple and more accurate. Also you can adjust the centering force, changing or tighting the rubber.
With medium size and high accurate, this is de most recomended.
It is a smaller version of the type 1, more compact but with some less precision and not suitable for engines larger than a PF M.
It is the larger but equally effective, ideal for high torques and flat spaces.
I hope this will be useful to you!!!
You can find more imformation about this ideas and other MOCs in my website:
I thought forcing the axle to turn while the motor was off would harm the motor. To avoid this I tried designing a self-centering steering system using differential gears and failed horribly (I am not an engineer). Was I being overly cautious? I don't want to cause undue stress on my PF motors and risk burning them out or anything. If this really is safe to do, you've saved me a lot of headaches when I try to build an RC car again!