Fadal VH65(DC) 4th axis with 7i77 - where to start?

I have a Bridgeport Boss 5 knee mill that was converted to AC servos controlled w/ a 7i77 and a 5i25. The previous owner/builder had it set up with a 4th axis w/ an AC servo and drive but I didn't buy the 4th with the mill.

I recently acquired a Fadal VH65 DC 4th axis at an auction for a pretty reasonable price. Admittedly, I didn't realize it was DC when I bought it.

Can someone point me in the generally direction where I can start to research what it will take to get this thing to work with my setup, assuming it's possible? Surprisingly, I can't find much out there about the VH65 as it seems most people use them to drop right in to pre-wired Fadals.

I would assume I need some type of DC driver/amplifier? A solenoid for the air brake?

Really just trying to decide if this is worth pursuing at this point or if I'm better off going after an AC driven 4th? Fortunately I know I can get my money back out of it so I'm really only out a little time (and back ache from lifting) at this point.

It is possible you might only need the air solenoid.

It all depends what you have already. Does your machine have a servo drive for a 4th axis? If so what model? Many servo drives that can run a brushless 3phase (AC) motor can also be used to run a dc brush one.

If you don't have a 4th servo drive suitable for running the motor on your rotary axis, you will need to find one.

To find a suitable drive for your motor you will need find all of the specs on the motor nameplate. (and maybe even some that are not.)

I don't currently have a drive for the 4th.

The problem I'm running in to is I can't seem to find the specs on the VH65. It seems to be a very popular rotary, but more as a direct drop-in on the fadals that come pre-wired for them. The data plate has nothing on the specs. I'll probably pop open the cover and see if there's a tag on the motor itself.

The other question I guess, is I've been told it has a BCD encoder - any problems getting that to work with the mesa?

That's not the motor or the motor name plate (that is the nameplate for whole rotary unit.)

I think the motor would be inside that box. (But I have no idea what snakes you may find in there.)

The vh-65 uses a dc brush motor made by Glentek and a direct coupled resolver. I want to say it s driven 90:1 worm/worm wheel. The manuals for everything fadal are online. The shaft on the motor is 1/2" in diameter. A Yaskawa USAREM-05 would be a good ac motor for that table, you can pick them up on ebay for about $300. The fadal table does not have a home switch, it was originally lined up by grid point on the resolver, you parked the machine on an alignment marker and the machine searched for the closest grid point on start up. You could also put a cheap encoder on the dc motor and run it with an inexpensive drive, say AMC 25a20. The motor is 90 volts.If you decide to change the motor out, ill buy the Glentek from you.

^ Good info!

The data tag I posted earlier in this thread confirms it's a 90:1 ratio.

I actually pulled the motor cover over the weekend and found what appears to be a very new Glentek motor. I don't love the wire splicing job I found, but that can be cleaned up.

My plan is to test the motor and hopefully encoder before I go too deep in this. Since this is DC, I'm assuming I can feed something like 12v DC directly to the motor leads to at least test it for motion?

It doesn't have an encoder, it has a resolver. Yes, 12v from a car battery will move the motor, it will run about 200 rpm with 12v.

Alright, so it's only been about 9 months, but I've finally freed up some time tackle this.

I've verified that the motor is good by putting 12vdc to it. I believe it was brand new.

My current setup uses Yaskawa SGDV-5R5A01A drives on the current 3 axis. From what I can tell, they're DC only - so though I'd love to use the same for the 4th axis, doesn't sound like it'll work. I also have a few Yaskawa SGDA-08AS, but I believe they're also AC only.

Can anyone recommend a good, reasonably priced drive I should pick up for this? Must be single phase...

And where can I start learning about the resolver and how to get linuxcnc to "see" it?