The...
Laptops contected to the driver ...
The drivers connected to the motors ....
The motors connected to the ballscrew
The encoder feedsback to the driver
And here's the word of the lord
So yes you are right. The easiest way to run your machine is from the parallel port, two pins are assigned to each axis, one for direction the other to tell the drive to step. You might think that servos don't step but the encoders are digital and using a driver such as a Geckodrive (
www.geckodrive.com) you can make them step. The result is really smooth motion, you don't notice the stepping.
Your A and B axis will have to be geared down heavily using either wormdrive, harmonic drive or a massive great gear or a combination, not easy at all, this you need to sort out before making the rest if you can as it will effect the design. You also need to consider the backlash etc.
Do you know what software you will use? Driving 5-axis is easy, turboCNC (runs in dos free to try and excellent) does upto 6axis and Mach2 (runs in windows also good) I think will run 5. However software for creating tool paths and g-code is less easy.
Check out this site:
http://www.rainnea.com/cnc.htm
He has written a free plugin for creating toolpaths, it is good but a little complicated. The software is for 3Dstudio max but there is a program called gmax which is a free limited version but you can import into that from Rhino and similar 3D programs.
Home this is some help.
Graham
oh yeah, pairing up servos is a bad idea, use one motor and couple the two ballscrews with timing belts, or use timing belts instead of ballscrews and couple two of these. Don't be scared by talk of timing belts or even rack and pinion, they work well and often better than people actually need.
p.s. Geckodrives are on special offer now I think