I cant build a distance constraint, please help me

[ipoirot]

I am doning the simulation of a robotic arm called PUMA 560 with Bullet. But I cant fix the arm on the shoulder joint.

want.JPG

In the programme, I used btHinge2Constraint. When force is not added on the manipulator, the result is just like the above picture.

but.JPG

Whe I applied a force on the arm, the arm was away from the shoulder joint.

I did a distance constraint just like http://bulletphysics.org/Bullet/phpBB3/ ... t=pivotInA, but It did not work.

ODE.JPG

It is very simple to bulid a manipulator in ODE.You just need to set the anchor of hinge and the axis of hinge.But from Bullet I would benefit from more reliable and complete collision detection, soft bodies and many other features that ODE does not have.
Please help me, thanks very much