I just got an Ex-Cell-O Spindle Wizard mill to retrofit.  It's a large machine with 40" x 20" travels on the table and 5" on the quill.  The table slides on tubular ways/linear guides.  It has 5 tpi precision ground ballscrews all around.

The original control was a bandit hooked up to siemens drives and motors with tachometers and resolvers.  I'm looking for new motors with encoders but the motors are Nema 42 and the places I know of like homeshopcnc, etc don't seem to have anything larger than Nema 34.  I've found some Nema 42 steppers but I much prefer the idea of getting servo motors.  Does anybody know of a source for Nema 42 servos fitting a home cnc retrofit budget?

I'm also considering picking up ac servo motors and drives off of ebay.  It seems like there are more comercial systems that use ac servos for motors of this size.

The overal plan is: mach on dell's latest pc model on sale -> grex -> new drives -> new motors

I figure with the grex I'll be able to hook up all of the limit and home switches as well as the air controled devices like the mist coolant, spindle brake, spindle lock, back gear, and speed control.

If the servos and drives are functional you might want to consider keeping them and getting a Step,Direction to analogue converter such as the pixie board. Would certainly be a lot cheaper and would save a lot of hassle.
Hood

Thanks.  That sounds like an idea.  I haven't even put power to the machine since it's three phase.  I haven't decided what I want to do about that yet. 

If the servos and drives are functional you might want to consider keeping them and getting a Step,Direction to analogue converter such as the pixie board. Would certainly be a lot cheaper and would save a lot of hassle.
Hood

Also the bellows on my table ballscrews seem to be flaking on the inside.  Anybody know a good place to order rod bellows?

is there a defacto standard way to remove the spindle motor on these things.  I want to pull this motor off so I can measure the shaft and bolt circle and find a single phase motor to replace it with.  I'm new to this and would rather not dissassmble more of the head than I have to out of ignorance.

I'm guessing I remove the front plate of the head that says Ex-Cell-O?  It has motors that drive chains to operate whatever is in there to mechanicall shift gears and control spindle speed.  Unfortunately I don't know what's on the inside of that face plate until I take it off.

I've done some cleaning up and probing with the idea of keeping the motors and drives that are on it.  It turns out that a lot of the documentation I got for it is incorrect.  I don't know what the motors are but the drives are neither the siemens drives or the standard drives described in the bandit documentation I have.  I'll post pictures.  Maybe somebody is famliar with the bandit contro/drives and can share some helpful information.

I checked the power supply and it is functioning.  It is a 60V DC power supply.  I'd like to check the drives and if they are functional retain them and use pixie boards with them.  My hurdle to this is I don't have any documentation for the drives to tell me the input pins and they way they are wired doesn't give any hints.

The following drawing of the motors seems to be correct.


In the back of the Summit Dana Bandit box are 3 drive cards which connect to the resolver phase logic card/motor control card with a ribon cable.


Up in the card rack is the resolver phase logic card.  The resolver cables plug into that card and then it outputs its signals to the drives through a 16 pin ribon cable.


The ribon cable connects to all 3 drives.  I pulled the ribon cable from each socket and wrote down which pins are present on each connector in order to identify which pins are common to all drives and which pins are unique.  There are 4 pins that are common to all the drives and 4 pins unique to each drive.  The pin numbers I wrote down isn't an actual pin number it was just an easy system to use to draw a connector without making mistakes.




If anyone knows the pinouts of these sockets or knows where I can find the pinout for these sockets or how I can figure out the pin out of these sockets, or has any idea at all to get me past this hurdle PLEASE share.

Anybody know a good place/way to find out what pins are what on these drives?

Anybody have any advice or suggestions on where to ask about the best way to free the spindle motor of the belt and even more importantly propperly tension the belt?

Ok, I'm finally getting to this.

I've decided to rip out and keep only the power supply from the control. I'm keeping my DC servo motors and replacing the tachometers and resolvers with encoders.

The set up I'm going with is:

US Digital H5MD-500 encoders http://www.usdigital.com/products/h5/
US Digital EA-R10-W5 differential receivers http://www.usdigital.com/products/ea/
GeckoDrive G320 DC servo drives http://www.geckodrive.com/product.cfm?pid=13
GeckoDrive Grex G100 http://www.geckodrive.com/product.cfm?pid=19

I'm using the G100 so I have enough I/O for all the relays and limit and home switches and to give me acurate timing--I'm thinking with the G100 handling the timing I may run the mach mill software on a laptop and not have a computer dedicated to the control of the mill.

I also decided what to do about the 3 phase spindle motor.  I ordered a varispeed drive from WEG that takes single phase input.  This both takes care of my 3 phase problem and makes it easy for me to control my spindle speed with mach.  It has a pwm input.
http://www.weglibrary.com/pdf/cfw10.01.07.pdf

I still haven't taken the top of this thing apart.  If anyone is familiar with them and has any insights on what to take apart first to remove the belt and get into the mechanical mechanism it has for speed control now please do share.