I had a Chinese 3040 4-axis cnc turn up today. A first look and it looks pretty useable. With one exception, the chuck timing pulley has been made with too small a PCD, the belt doesn't mesh properly. The seller is a drop shipper and I got it 25% off after someone else bought it then returned as they didn't have a parallel port. I'm therefore thinking that I should just put a new pulley on. I can't find a stock replacement so I'm thinking why not make it larger. That the means a pulley and a belt. With another pulley, I could change belt type. It currently has a good 12T stepper pulley and a no-good 27T chuck pulley. belt is 3/8"XL. What do the experts think of changing to 2mm GT2? Perhaps 20T and 100T It's only a 80mm chuck, but with a larger reduction could be useful. Steppers are nema 23 about 2 1/4" long. I'd also like a much higher rpm spindle for it for grinding cutting tools. I would like to make my own fly cutters to cut ribbed belt pulleys and no doubt other things. Any suggestions for high rpm spindle motors than aren't hundreds of dollars? I'd prefer something that will take 1/4" shaft tools as there is a wide selection of diamond burrs in that size. I have a Makita router but it seems a bit big for a 3040?