SketchyPhysics help please

Hey all,

i have troubles with robotic arm i just want to make last joint and it not work as i want can you please guys say what iam doing wrong with this last one ? Why theese two things torn off apart ?

Here is my problem

Robot.mp4 (2.4 MB)

If you haven’t put a lot of work in the bottom part, the SketchyPhysics shape of that block will not look like the visual one. You can activate the debug mesh to see what I mean. (I would have shown it to you, but I don’t see the attached model).