Strange behaviour-Prismatic joint rotates around its z-axis

[nfys]

Hi,

I am trying to build a simple cart-pole system. I am using a prismatic joint to move the cart and a revolute joint that holds the pole. When I simulate the setup using bullet physics engine I see that the prismatic joint is slightly rotated wrt to its z-axis as if dragged down by the pole's weight. I cannot understand why this is happening. Is there a way to eliminate this?

My scene file is available here:

http://speedy.sh/HBj9A/cart-pole.ttt

I am completely new to VREP and I will really appreciate any help.

[coppelia]

Hello,

make sure you read this page, mainly design considerations 6-8. Your linked masses and inertias are too different.

Cheers