I recently saved a pair of Pratt & Whitney Drill Mates from the scrap heap hoping that they would be good candidates for a retrofit project.  The biggest obstacle I see with these machines is retaining use of the ATC, which is quite a unique design-very similar to a Fanuc Robodrill (http://www.youtube.com/watch?v=LkQZclaOSz8 first 0.07 shows tool change) or the Brother tapping machines, only completely mechanical-I am on here to ask if anyone has any advice on how to program this ATC.

The tools are held on a turret that rides on the front of the spindle, and rotate around the Y-Axis.  The tool never leaves the turret on these machines, but is held loosely in its slot by a C-Clip and a bearing.
When it is time to perform a tool change the machine rises to its max working Z height, then it uses some sort of cam actuated by an additional Z-Axis movement upwards to swing the turret forward/away from the spindle, as it does this the cam releases the tool holder shank from the spindle, and the holder rests in the turret.  With the turret positioned out away from the spindle it can rotate to the next tool.  As Z lowers the turrent swings backwards/towards the spindle and the cam engages the holder, then it drops back down to the working Z height and off it goes.

I have never done an ATC in Mach3 so starting from the beginning my questions are:

Do I need to run the turret as my A-Axis?
Do I need to set soft limits to control where the Z-Axis goes to begin the tool change?
How the heck do I program all of that automatically into Mach3?!
I have seen some of the tutorial but I'm kind of intimidated...

Any help would be MUCH appreciated!

Unless the turret uses a stepper or servo motor then no you will not set it as an axis.

No need for soft limits for it, you will just command a position to move to, however softlimits are always a wise thing to have on any machine. If the axis has to move beyond soft limits to do its changing then your M6 macro can disable/re-enable softlimits as required.

All done in the M6start.m1s macro, how exactly will depend on the exact steps/sequence required, often a PLC is a good way to do this as it handles things externally and the macro only needs to signal to the PLC and wait for a signal back. All depends on exactly what is required and which is easier for you personally , VB or Ladder.

It will be intimidating but like everything else when you know the exact sequence required, know the I/O you have and what order etc then the battle is half won.

Hood

There is a small servo on the machine now that controls the turret location.  Since all of the motors on these machines are analog servos I will probably be replacing the axis drives with some Nema 42 steppers and a 23 for the turret on one machine to test it.
I was wondering about limits just to prevent the machine from accidentally going to high and dropping a tool if it somehow skipped a step or through operator error-if I can set limits that will stop the machine but can turn off during the tool change macro that would be perfect, I just have no idea how to do that-my Mach3 experience is pretty limited so far, and I have exactly zero experience using a PLC...

Personally I would look at one of the analogue capable controllers that work with Mach and use servos with analogue Amps/Drives.
There are a few and I have used the CSMIO/IP-A and think its the dogs dangly bits.
The other two I know of are the DSPMC and the Kflop with Kanalog.

Hood

I didn't even think to see if I could find a way to run the older servos aside from fixing the existing Fanuc control equipment...
All of my experience so far has been with steppers and the servo tuning is a bit intimidating, also the cost of these kits seems a bit prohibitive; do you have an estimate for the cost to set up the CSMIO/IP-A of Kanalog systems (for 3 axis plus the ATC)?  They both appear to be in the same price range.
Keeping the existing motors would be awesome if I could make it work!

I am not really sure of the total cost as with the CSMIO you would likely want the MPG module so that you could use for panel buttons and the MPG itsel. See screenshot of my panel.
The CSMIO is 24v for its I/O so is easy to integrate to an industrial machine.
Think the Kflop is 3.3v but the kanalog may be 24v, not sure on that, if not you will likely need extras to interface..

One word of warning, some Fanuc amps use funny signals for the control so make sure yours can accept +/- 10v input if you go down that road.


Hood

Think the Kflop is 3.3v but the kanalog may be 24v, not sure on that, if not you will likely need extras to interface..

KFlop is a mix of 3.3V and 5V tolerant (i.e. will only source 3.3V, but can withstand 5V input). The Kanalog can handle upto 24V through the optos, or 80V through the FET relay drivers, however the biggest drawback I find is the Kanalog only has 8 opto inputs. It does have other inputs available via a pin header, however they're low voltage. It also has eight 0-10Vanalog inputs, which you could probably use for digital inputs with a little bit code.

Could you help me piece together a simple kit to run this so I can get a better estime of the cost for a 3 axis (with potential a 4th) plus ATC?  The servo setup sounds ideal but it also sounds a lot more technical than the stepper systems I am used to so I dont know where I need servo specific parts like drivers or extra wires/connectors for encoders, etc...
What servo drives can I use with these systems-can I run anything or does the analog encoder require something trick?  I think I should be able to hack my way through the programming, the electrical stuff is what really gets me overwhelmed at the moment.

I will post the Fanuc motor specs as soon as I am able to.

If going the CSMIO route you will have the CSMIO/IP-A itself and I would recommend also the MPG module, not the pendant, just the module, unless you wish to have the pendant of course . You may require an extra I/O module as well depending on the amount you will require.
The only real advice I can give is study what you have, try and work out what connections you will need and that will help you decide.

The analogue output controllers for Mach can use any analogue controlled amplifiers, in other words if your amplifier/drive gets its command from a +/- 10v signal they will work with these controllers.
All of these controllers will also require that you can feed the encoders back to them so either the encoders on the motor need to be 5v ttl signals or that any simulated/pass through signals from your drive are that.
To explain the last poart I will give an example. Some of my machines use Sine/Cosine encoders on the motors, these are not suitable for the controller. These signals however are read by the servo drive for its own use and then the servo drive will condition these signals and pass them out as square wave signals which are suitable for the controller to use.

Sorry its not a huge amount of help but without knowing the specifics involved its impossible to say what is required.
Hood

Spindle Motor:

Fanuc AC Spindle Motor Model 3 Type A068-1003-B 100
Torque cont 3.7 kw
Amp cont 17 A
200 V
1500/6000 rpm
Its square and really heavy so I assume it really is an AC motor and thats not just some random part of the name

X and Y Motors:

DC Servo Motor Model 5M Type A066-0642-B012
Torque cont 5.9 Nm
Amp cont 9 A
151 V
2000 rpm

Z Motor just looks like a scaled version of X and Y I will get the specs on that ASAP, I just pulled those from pictures on my phone...
I can look through the piles of books for wiring diagrams and potentially find info on the encoders.  Would it be possible to put new encoders on?
What kind of drivers can I run these servos off?  Like i said I'm 100% new to servos, and to anything of this scale....

My ultimate goal is just to get these machines running well enough that I can cover my expenses, take my girlfriend out to dinner for putting up with this project, and buy a case of beer for the guy who has been storing these for me.  If I can change tools, do some light cuts on steel plate, and cut aluminum at 40ipm I would be super excited-I'd honestly be really excited to see it work at all.