The tolerance issue in 3D printing

These broken parts are gonna delay my work ...

The conjunction between the motor led and the robot body

The broken conjunction on robot body side

The broken conjunction on Motor side

 Totally new printed encoder parts were received on 9th of May 2011, and one of them(picture below) was broken into two pieces while being mounted on the same day

The old broken encoder part(black one) beside the new one that was broken under mounting

Challenges ...

New challenges with the robot arm, while I am working with positioning. The prototype(robot arm) is not totally functional as just one of the three motors work the way it should. Problems with mechanic design, and the motor axle is worn away(3D printer product in plastic) ...