My only complaint is it's slow, the fastest I've run it is 50 inches a minute. I've tried about every trick and it just doesn't want to go any faster.
Have you tried converting X and Y to ballscrews? If your steppers have enough torque, you can get .200 pitch ballscrews that would double your speeds if you currently have .100 acme leadscrews.
It doesn't come without cost though. Theoretically you lose resolution, but the ballscrews will be more precise across their entire length. So basically, if you're getting .001/step with leadscrews, you'll only get .002/step with ballscrews. But with leadscrews, a 1.000 inch move on one part of the table may be 1.010 on another part due to the lack of precision. Ballscrews, especially if they're ground, are going to be the same moves all over the table. All this is mostly irrelevant to the prop builder though, due to the materials and tolerances used.
You could also try belt drive. It's tougher to hold tolerances, but you can get .005 pretty easily, and that's better than the expansion qualities of MDF. Belt drives can go INSANELY fast, but you really see benefits in rapid speeds. You can realistically get 300ipm rapids, but you probably wouldn't want to cut anywhere near that speed.
I know from my experiences it's agonizing to watch your machine moving through air, not cutting anything, at 50 ipm.
This is mostly for anyone looking to build a CNC machine. This guy on eBay,
eBay My World - momus_design, has a CNC design that is belt driven and can cut aluminum using a trim router. The plans are very well written, but if you're not very handy with tools I would go with the OP's book until you outgrow that machine. I bought them, but got halfway through the build and decided to convert a manual milling machine because I'm going to be cutting alot of steel and aluminum. I may finish and sell it however.
Anyway, good luck to everyone. I'm glad to see CNC becoming more mainstream.
