I've just taken delivery of a full sized knee-mill (a Sharp bridgeport clone with 3hp/4500 max RPM vari-speed head). It was converted to 2-axis CNC over a decade ago, but the controls are dead. So, I've got a mill with X/Y ballscrews, an appropriately sized power supply, and servos with mechanicals on the X & Y axis -- a great place to start a retrofit. The current servos are 70V Nema 42 size, so I'm going to go the Mach 3/ Gecko G320 route. I've already got a VFD to run it on the single phase in my garage/shop (GS2 from Automation Direct).

Some questions for the list (any & all input greatly appreciated - I've never done this before):
1) Z-axis: I'd like to CNC-enable either the quill or the knee. Currently, I'm leaning toward the knee due to greater travel and less cost/complexity.
- Anyone out there got drawings/.dxf's for knee mechanicals they'd be willing to share?
- Anyone know a source (other than eBay - I'm watching it) for NEMA 42 servos appropriate for the knee?

2) Motion controller: I'm willing to fork out the $400 for a G-Rex, since I'm tempted by the smooth, fast motion it promises, plus I won't need to invest in a breakout-board (which removes the p-port requirement on the computer). However, I hear an awful lot of problems/complications with that unit.
- Is the GRex worth the hassle?
- Is the ncPod with a ModIO unit likely to be a better bet? (I do want to use a pendant of some sort and understand that the ncPod won't support one, hence the need for ModIO. ModIO also makes up for the IO shortcomings of the ncPod in a big way).

3) Home/limit switches: Looks like these got pulled from my machine. I have to say, this is the area I know the least about, so any help here is appreciated.
- Does one run home *and* limit switches for each axis (meaning 6 switches)?
- How exactly (or even generally) are they positioned/set up?
- Can anyone recommend a source/part number for such switches?
- Are home/limit switches easily/well supported by the G-Rex?

4) Computer: I'd like to put the computer in the current enclosure that's bolted to the mill. A cheap Dell or other standard size computer won't fit. Rather, I probably need something like a mini-ITX.
- Any recommendations for a motherboard/barebones setup? Preferred vendor? I know there have been problems with certain chipsets, is there anything I should explicitly avoid?

- The other approach would be to use a touchscreen panel PC. I'd like to keep the computer/screen budget under $1000. Do panel PCs exist that meet the spec (~1Ghz processor /512 MB RAM) for that price? I haven't found anything on eBay.

5) Monitor: If I can't locate a panel PC, I'd still like to use a touchscreen monitor. I've found a good deal on a 15" one ($300), should I splurge the extra $185 for a 17"?

6) Tooling: The machine didn't even come with a single collet. I need a vice, collets, end-mills, etc, etc
- Any recommendations for good/cheap tooling besides Grizzly & Enco?
- I've been looking at the Tormach Tooling System (TTS). Looks like a good way to ensure consistent Z-offsets. Anyone got one that cares to comment on their value?

Thanks in advance for your input. I've been wanting to do this for years, and am excited about finally starting.