With the day off yesterday, I had a chance to finish wiring up my machine, and give it a try. It took a total of two hours to crimp all the plug connections, wire up the Xylotex, and hook up the power supply.
Once the motors started humming I thought I was done, but that was just the beginning. It took longer to work out the bugs than I thought but by 6 pm I was milling like crazy.
I did a few things that are not ususally done to build these machines, so I thought I would point them out to help any other people who want to build a dirt cheap machine.
1. I used 1/4-20 lead screw, and didn't trun down the ends to fit in bearings. Instead I just cut them to length, and got .25 id ball bearings.
2. First I tried using a timing belt to run all axis' lead screws, but that turned out to be more work than necessary. 1/4-20 rod is flexible enough to make up for any shaft mis-alignment, simply hard couple the motor shaft to the lead screw and call it a day.
3. I tried loading two nuts against the bearing at either end of the screw to keep it form moving in the axial direction. This isn't necessary when you hard couple the screw to the motor shaft.
4. I didn't bother with linear bearings or anything like that. I simply used 3/8 thompson rod, and drilled 3/8" dia holes through my axis supports.
5. I used cheap steppers from allelectronics.com.
6. Cooking oil is an excellent oil for lead screws and slide rails, allthough the first time your wife finds aluminum chips in her cooking oil you will have to get your own bottle.