- The PinkieStrong C clamp. A design exercise 'cause I like Armstrong heavy duty camp. It seems functional enough for light woodworking.2 o rings 2 balls 2 springs Lots of plastic. It works but drools when parked. I think the piston bore is buggered or the o ring groove is. Or both.Learned to print magnets in a part. Learned why they should have been heated. Learned that plastic is slick and therefore needs more magnets to keep the carriage from pushing it around (actually, some rubber would probably work better). Bunch of toothbrush magnets in there, you can see the outlines. Two piece assembly for easier printing.