Gearbox Thumb Screws
The Chinese 7x lathes don't have a quick change gear box, so I made some thumb screws for easy access to the change gears. My lathe uses M5x45 screws to hold the gearbox cover on. I picked up some M5x50 screws to replace them. I made aluminum collars to extend the heads out past the cover. These collars were approximately the same diameter as the head, 0.300" long and drilled for a press fit on the screw shaft. For the thumb screw caps, I knurled some aluminum and chamfered the edge. I wanted to have the caps closed on the end, but I got numbers screwed up in my head and drilled too deep. Rather than scrap the piece, I decided to stick with the open end. It doesn't look bad, and if they ever get too tight, I can still get the allen wrench on them. The caps were bored for a very tight press fit and pressed onto the screw heads with a vise. Click the pictures for larger images.