Found this ancient post through google believe it or not. Ive been having some issues with my Uncle Roy machine. Been using it for whip shading recently and took the o-ring route as regards to needle tension. The machine aint spitting ink or anything, but it seemed really weak at driving the ink home. Upped the volts but no real difference. Then I noticed the o-ring had worked its way down the backplate and was actually burning into the top of the plastic tube!!! Ive noticed on some set ups that a couple of bands positioned near the top of the the needle bar and over the clippy contacts has been utilised anyone tried this method??