Is there a sticky post or FAQ or something of the sort that describes the various pieces of hardware necessary to create a working cnc system using Mach ?  I want to retrofit a mill for 3 or 4 axis machining.

Thx
Scott Kelley

Scott,
 there are so many variables I dont think any one suggestion would work.
 Tell us a bit about the Mill you have, is it already CNC? What size is it? etc etc

Hood

And - where are you based.

It is supposed to be a global market, but some things are easier to get in some places than others.

This is a Bridgeport "Boss" (R2E3) mill.  For those not familiar with these machines, it is factory built as a 3 axis CNC.  It uses 140 volt brush type DC servo motors.  In terms of size, it is pretty much equivalent to the manual Bridgeport "Series 1" that everyone is familiar with.

I am in the US (Oregon).

Thanks
Scott

I have a Boss 6, similar except mine uses steppers.
 Ok for yours you will need servo drives but without knowing the Voltage and current of your motors cant say which would be best. I would imagine they will be within most of the  common servo drives current capability but the voltage may not be. I would guess the voltage to be about 140 to 160V so that would rule out the Geckos or Teknix drives unless you can settle for lower speeds (Volts= speed, Current = torque)
 The most common servo drive people that people here go with are
www.geckodrive.com
www.cncteknix.com
www.rutex.com
www.larkencnc.com/viper/index.shtml

There are also industrial drives which can often be had on eBay but you will need to make sure they can accept Step/Direction signals, a lot, especially the older ones are only analogue.
You may need encoders, depends what you have on your motors now.
You will need a power supply but you may already have that in your mill.
A breakout board will also be needed (not totally needed but best to IMO others disagree   )
That will build you a very basic mill but other things can be added, MPG, Touch Screen, SmoothStepper etc etc etc.

Being in the USA you can get most things easily.

Hood

As noted, they are 140 volt brush type servo motors.  The encoders are a BEI model that I think I have enough info about to be able to use them.

For motor drives, I have seen that Rutex and Viper are both available in a 200 volt model.  It was suggested to me that there have been some problems with some of the Rutex drives - any thoughts there?

The area where I am pretty well baffled is that of the interface between the PC and the motor drives, limit switches, etc.

I have never had Rutex or the Vipers so cant say from experience, I have certainly heard of the Rutex being a bit tempramental but can only go on what I have heard/read.
 Ok for computer to limits etc, there are a few options, simplist is the Parallel port out to a breakout board then your limits etc go to the breakout. Actually the simplest is direct connection to the parallel port cable and doing without a breakout but I am not a fan of that You can have a second parallel port as well if you need extra I/O.
 Next option is the SmoothStepper, its a USB motion controller so does away with Windows having to do the pulseing, it has a 4MHz max pulsrate as opposed to the parallel ports max of 100KHz (in reality 45KHz may be the max) You can use the SmoothStepper without breakout boards but again I prefer to have them. The SmoothStepper has the same I/O as two parallel ports and also has another port which can be connected to encoders or used for other general purpose inputs. (4 if I remember correctly)
 There are also a few other options such as the G100 (G Rex) and Galil but no experience and from what I have heard the G100 especially is maybe not a good option for Mach.

Hood