pic: MOE 2007 - MOEzilla

[The Lucas]

Originally Posted by Joohoo

Sweet looking robot

424 grr used an arm simmilar to your design. We weren't able to control which arm segment went up first did you figure something out to fix that?
or did you just not encounter that problem?

Early in build we had problems with the large white slider (in the picture between gripper stage and next stage) seizing in the bosch tubing tracks. That made the stages go up unevenly. After fixing the sizing of that slider, the stages lifted smoothly and consistently.

As Ben Piecuch pointed out, this is essentially the same lifter we used 2 years ago (right down to the window motor rotation) so we had some time to tweak the design. I don't know specifics (being a control systems guy ) but I would guess:

the sliders (possibly different for different stages),
staggering of the stages,
tensioners and
double winding (one chord pulls up and the other down)

One or more of the above has something to do with it (I just basically named every part). Stop by our pit at FLR and someone much more knowledgeable than I, would be happy to talk design with you.