Simple rotating wheel

[slembcke]

You probably don't mean to prevent it from updating the position. That tends to be a very bad thing.

You should try using force limits instead. Otherwise the force used to correct the two joints will fight and both will grow in an unbounded fashion each iteration of the solver. That's why I used force limits in the demo code. The mouse grabbing should have a soft force limited feel to it to simulate the way that you would really be able to manipulate things in real life.