I don't actually remember at what point I became interested in converting my RF40 to CNC, but apparently it seemed like a good idea to me at the time. I guess a large part of my interest in CNC is I'm mostly a computer programmer, so computer control just seems natural.. In designing the CNC conversion, I wanted to retain manual control of the milling machine and I wanted to make a conversion that did not require any modification of the machine itself. I think I met those goals pretty well.

	I made a pretty simple frame out of 4 3/4" posts, drilled and tapped on one end and are turned down on the other end to fit in a locating hole.		The turned down end is a slight interference fit in the hole in the plate.
	All of the pieces were made on the mill.. Getting the posts to the correct height (they're all the same within a few tenths) was a little interesting. I was really pissed when I broke a tap in one and had to make another!		Once I had everything together and I checked that everything was square, I welded the non-tapped ends to the plates. It would have been nicer to use bolts but then I would have had to drill clearance holes in the mill and the motor to clear the bolts heads which wouldn't have been nice!
	I used a cheap Lovejoy coupler because I couldn't find anything better that could be used with the 17mm lead screw shaft. I shimmed the spider so there is zero backlash.		In retrospect, I probably should have welded both ends as I didn't need to be able to dissasemble the frame in order to attach/remove it from the mill/motor.
	Because I wanted to retain the use of the handles, I wouldn't be able to use a direct drive on the Y-axis. Instead I designed a bracket that would use pulleys in a 1:1 ratio. Because I'm too cheap to buy layout dye, I used a Sharpie to give contrast to my layout lines.
			Because the bores need to match up precisely, and I don't have a DRO, I drilled some locating holes and then bolted the three pieces together.
	I then drilled out the four holes that attach the bearing housing to the main assembly.		On the Y-Axis, I'm actually replacing the stock bearing housing. Whereas on the X, I just displaced it slightly.
	With the backing plate and the front bearing housing bolted together, I bored out the bearing holes. I didn't have a boring bar so I used an end-mill in a boring head.
			All anodized and ready for assembly. See my page on anodizing for details.
	My helper says she's ready!		My first attempt and using inexpensive capacitors ended up spewing capacitor juice all over the place.
	With a real cap, everything works great! I'm using an AC light rheostat to control speed right now..		Here's the computer with the Gecko cage
	The light rheostat works pretty well, except it won't go low enough to drive the servos at a suitable slow speed. But it certainly is nice on traversal!

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