Algodoo

they collide each other because the polygons are not the same if you triple click it then they are all not selected why not try to make them same and turning on No self collison.

I suspect they keep interacting because the system is over-constrained since only two axles are needed. Delete any one of the three axles. Select all three polygons (or just the outer two polygons) and set to No self collision.

Note: There are no collisions in the original scene. This can be verified by putting colorHSVA = [rand.uniform01*300,1,1,1] in the onCollide event for each arm. Congratulations on finding a glitch.