TIP: Correct driveshaft U-Joint phasing to minimize vibration


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Berkeley, CA
Arrma RC's
  1. Nero
If you're running dual u-joint driveshafts like those found in the Nero, make sure they are installed with the correct 'phasing'. If you've ever taken your shafts apart and not thought about this you could be introducing non-constant velocity rotation to your wheels and drive train.

Here is an informative video on the potentially non-CV behavior of u-joints:

U-joint phasing:

As noted in the video the dual u-joints cancel out each other's non uniform velocities. A consequence of this is that drive systems that use a single u-joint (dog-bone on the other end) inherently have this vibration issue and should be avoided. Either go dual u-joints, or full dog-bone.

Don't know if this was common knowledge to RC'ers, but it wasn't obvious to me up front. I've since correctly phased all my Nero's drive shafts. Hope this helps you too.

Have you seen much of a performance improvement after doing this?
On my workbench I could see the driveshafts shake at speed, and now are spinning smoothly. Haven't measured the effect on speed on the ground.