Articulated systems without featherstone constraint solver

[peltonen]

While waiting for the featherstone constraint solver, does anyone have any advice on how to minimize the amount that Bullet constraints 'break' when under force -- in particular, I'm referring to constraints that are attached together in a series (for example an articulated robot arm or robot walker)?

[Erwin Coumans]

We are working on improving the current constraints currently.
Large mass ratios and large constraint offsets can cause issues.

Could you help us with a test case, and re-create a basic robot walker that shows the constraint instability/weakness?
(you can attach zip files)
Thanks a lot,
Erwin