Why does it need higher speeds? Is it just a matter of practicality vs patience, or is there an actual reason to have the higher speeds?
To start out with, I'm thinking of getting "whatever" steppers I can find, adapting them through pulleys/gears to the torque I actually need, and then upgrading as better parts come available.
By driving it from a smallish shaft to a larger pulley, I should be able to increase the effective torque and resolution of "whatever" I can find. And, it doesn't seem to be too hard. It might make the machine painfully slow, but it should work...and suffice till better parts can be had.
I'm going to use that braided air hose coupling trick that was mentioned on the board -- good tips on here, and on the RC forum. I've already mocked up one of my screw drives, and it works just fine. Support bearing on each end, air hose coupler design, etc. Works great, even if it is only 6" long at this point. Like I said -- it' a mockup.
I have a computer flea market event coming up next weekend -- it's obvious what types of things I'll be hunting for. There's usually at least 1 guy down there with steppers and otical components...and another with broken LASER printers and Xerox machines. Both should prove to be good sources for steppers.
-- Chuck Knight  |