Gecko Drives and Fanuc servos?

[Radius]

First, I'm a complete newbie at this retrofit game.

I've searched around a bit but didn't really come up with the answers I was looking for.

I have an Ikegai FX20 2 axis cnc lathe with a Fanuc 5T control. I dislike the control due to the lack of a crt. It's hard to see what's going on with the thing.

The lathe works as it should, but I'm considering retrofitting it with a Mach 3 setup and I have a couple of questions.

First, I believe this control has DC servos on it. Is there a Gecko drive that will interface with my existing servos? Do I have to use the existing Fanuc servo drive boards or will the Geckos supply power to the servos?

What about the encoders for the servos, spindle, etc? Can I use the stock Fanuc servos?

The tool changing turret on this machine is electrically controlled. I'm not sure if the motor is AC or DC, but I suspect it is AC. How do I control this?

Last, and probably most challenging. The lathe has a 7.5hp DC spindle motor with associated spindle drive unit. I am under the impression that I could replace the spindle motor with an AC motor and install a VFD to interface with Mach 3. But, due to the costs associated with this, I would prefer to use the existing spindle motor and drive for the time being. Is it possible to interface Mach 3 to this existing spindle drive?

What complicates matters is that I have no schematics for this 5T system. I've figured out a lot of how it works by tracing wires, etc. So at least I have an idea of how it works.

Thanks,
Michael

[Al_The_Man]

First off it is pretty certain it is DC servo's, depending on the size (Voltage/Current) you will need to get the Fanuc model (e.g. 10, 20 etc) in order to size an appropriate drive.
As long as they are incremental encoders and not resolvers you should be able to make use of them.
It may be more practical to use an outboard PLC to control the tool changer and just issue it a command via a M or T code.
The spindle amplifiers were typically ±10v analogue control, as were the servo drives, so if you used mach etc, you will need a step/dir to analogue convertor.

Take a look at this site someone posted today, it looks interesting and may be the prefered way to go.
www.cncmaker.com
It will help immensely if you can get prints, otherwise there is a lot of reverse engineering to do.
Al.

[Radius]

Hi Al....

So, what you're telling me is that this will get pretty complicated and I should buy a ready to go kit?

The problem with that is budget. I don't have the cash to buy a ready to go kit, so my only other option is to build it myself.

Now that I think about it, I believe you are correct that the servos are DC. I have no idea if it uses incremental encoders or resolvers though. I think I know who I could ask to find out though. Would I have to use the original "velocity control units" or would the Gecko drives take the place of these?

What about this outboard PLC to control the tool changer? Is there a unit commercially available?

Also I forgot to ask about the hydraulic pump (for the chuck) and the lube pump. How would I turn these on with Mach 3?

Is there anyone out there that has done a conversion similar to this?

Thanks,
Michael