Originally Posted by
Bigdaddyswank
If you hit something hard enough that the upper arm durability is a factor, you have a whole other list of problems than that part breaking...
I'll second that. I finally broke one. And it only broke because the hinge pin stop was drilled out and the pin worked its way free overloading the back part of the arm and snapping it near the pin. Mine are V1, first ones off the printer and plenty strong.