Problem with copyrotation

In the link above you will find .blend that has one bone and one sphere copyrotted to it with influence of .75 or something (less than 1 anyway). When you open the file. Roll the frames forward and keep your eye on the ball, you will notice odd “flip” in local axis coordinates and the ball flips. How do i get it NOT TO DO THAT?

Please help.

Unfortunately, this is a limitation in the math involved. To avoid this problem, the only workaround is to use IPO-drivers for that.


And that is… difficult? I dont know about them much…

They’re not really that hard to use, it’s just that constraints are nicer to use most of the time.


Why not just keyframe the rotation of the ball directly?

What is the purpose of the bone / copy rotation ?

If you want the bone to move with the sphere, parent the bone to the sphere. (select the bone, then the sphere, CTR-P)


The mechanism shown in the blend is part of larger “machine”, which purpose i think is best left untold as i cant really explain it… And there is “Influence” involved so straightforward parrenting wont work.