I picked up a second-hand chinese CNC router/engraver a couple of months ago. Cast iron frame, 500x300mm working area, german ballscrews, no software and a manual in chinese... Finally got it all working (after much trial and error) but wasn't happy with the quality of cutting I was getting from the onboard RS232/HPGL controller. If I didn't have a Roland MDX 20 I might have accepted the 5mm/sec feedfate I needed to get a clean finish but the little roland machine makes really nice renshape parts at 15mm/sec (assuming I don't go too deep and stall the spindle). The "new" chinese machine seemed like it should be able to do better and faster. After pulling the covers off and doing some research it seemed like a fairly simple project to convert it to run under Mach3 - and it was.

I used the existing XY motors, drives, optointerrupter home switches and power supply. Z axis was driven directly from the controller board so I needed a driver (from http://www.oceancontrols.com.au) and I also bought a new motor for Z.  Breakout board was also from ocean controls. Local electronics supplier Jaycar had a parallel port 8 way relay board kitset so I'm using that to control the spindle and to cut off power from the steppers. Added a second parallel port to an old PC and got the router cutting last weekend. I also managed to get the breakout board and relay board mounted inside the machine. I still need to tidy up the wiring but it's all working. Solid 3 meter per minute in XY and about half that in Z (the spindle motor is pretty heavy so unless I can find a way to spring load or counterweight it that's about as fast as it's going to go). I also hooked up a touchplate made from 1/16" thick printed circuit board, a contour shuttlexpress and, the PC used to run a security camera and it has a video capture card, so I mounted an IR camera so I can remotely monitor the job - can't really see what's going on but at least I can tell when it's finished cutting a pass.

Ran some test cuts (to compare to a part I made on the Roland) and it's running pretty smooth. Also, since I could rough much more aggressively and cut without worrying about stalling the spindle I got the part cut in 2 passes in about an hour rather than 4 passes in 6 hours. I have another test I want to run which will really tell me if it's working reliably since the toolpath has thousands of rapids and z lifts.

There are some pics of the machine here:

http://www.b26354.co.nz/CNC

Now I keep looking at my Seig C6 lathe and thinking about retrofitting it If I can find some really cheap stepper drivers it might almost be worth converting the Roland to run with Mach3 (and since I have an aftermarket 4th axis for it I could run simultaneous 4 axis)

Also added a sieg super X3 with CNCfusion deluxe ballscrew kit to my growing collection of CNC machines.

http://www.b26354.co.nz/CNC/pictures/img_0036.html

Working on the electronics enclosure at the moment.

Oh... and I CNC'd a sieg C0 for fun - just to get a handle on CNC turning. This is what happens when you leave your micro-lathe lathe unattended for 20 minutes roughing a part from 2" diameter aluminium

http://www.b26354.co.nz/CNC/pictures/dsc_2278.html

My next project was going to be adding steppers mounts to an Emco compact 5 manual lathe but I just scored an "Emco compact 5 PC" lathe so I'll just swap the stock emco steppers for the ones I was going to use and it should be good to go.

very nice looking work!!!

Steppers look kinda small, you might have to go larger.

very nice looking work!!!

Steppers look kinda small, you might have to go larger.

I've already swapped the steppers on the X3 - those were just to get the thing moving while I waited for new motors to arrive. They  ran fine at 8 inches per minute
The new motors move X and Y at 80 inches per minute but I've slowed Y down to 40 so there's less chance of me jogging off the end of the  Y ballscrew (until I have limit switches installed).

Added Emco compact 5PC to my collection.

http://www.b26354.co.nz/CNC/pictures/img_0044.html

Replaced the stock steppers with some surplus nema23's and a mach compatible controller.

Only took about an hour to convert and get it cutting:

http://www.b26354.co.nz/CNC/pictures/img_0054.html

I still need to hook up the optinterrupters for spindle speed and build a decent enclosure for the electronics. I have a bigger motor on the way for the Z-axis to get faster rapids and a decent speed for threading.