Elox EDM

[Jim Estes]

I have an Elox 8-2012 EDM that came with a DIGISET DRO made by Anilam. That readout quit working completely, it was damaged and I have since bought a Fagor DRO for this machine. The Fagor DRO can control the Z axis in several ways. At present I can wire the cutoff switch to the DRO and control the final depth setting. I am wanting to completely get rid of the Digitset. If I disconenct the Digiset, the machine will not feed the electrode, there must be a wire that needs to be jumpered. Does anyone here know how to rewire the machine to work without the Digiset?

Another question I have for you guys is about the hydraulic servo valves. Does anyone know how to use replace those hydraulic servos with a mechanical servo and make it work? Or do you know who would know how to do this? I have already talked to EDM ZAP, but their prices are too high for this old machine. I can get the mechanical stuff and work out that, but the electrical is where I would need help.

Thanks,

Jim Estes

[Al_The_Man]

I have worked on the older Elox M/C's and I have the schematics for them, but not familiar with that one, if you had a schematic and could PDF it that shows where the Digiset is hooked into I may be able to help, When you say Mechanical servo, do you mean a motorized one, rather than Hydraulic servo?
Al.

[Jim Estes]

Yes, I have the schematics, I'll scan them tonight and send then to you. Yes I meant a motorized servo. The hydraulics work fine, I just don't like the noisey pump. I was hoping to quiet this thing down some.

Thanks,

Jim

[Jim Estes]

Here are the schematics, although I don't think they have enough information to help. Sorry I don't have a way to create the PDFs, they are JPG images instead of PDF. Schematic 002 shows the Digiset as just a tiny little box (center of the schematic), with wire 1 and 2 coming into it, I checked those wires and they have 120v across them, so I assumed they were the power supply. The other schematics that shows the DC power supply, shows the control cable for the Digiset but doesn't give any information about the wiring.

I have detailed blueprints showing all the components in the control cabinet, but nothing in them references the Digiset. I am thinking I'm stuck.

Thanks,

Jim

[Al_The_Man]

The JPG's must have been too big? Do not see them.
I would suspect there is very little control by the Digiset so it is probally one signal needs enabling as you note in your first post.
I looked at the older schematics I have on the Elox and it shows the schematic of the Servo option, a very simple amplifier, but shows a wound field motor! Which I am sure a modern PWM amp and servo could be used, you would however have to replace the Hydraulic cylinder with a ball screw, probabally high lead type.
BTW if you need a PDF program, there is a freebe www.PDF995.com, installs as a printer.
Al.

[Jim Estes]

Thanks for the PDF info, that's awesome. I also have a schematic of a mechanical servo option. However my machine didn't have the option. The ballscrew conversion would be simple, there is already a nice bracket to mount the endbearing on, there is also plenty of space for pulleys and motor. What is the big difference between the signals to the servo valve and signals that you would use for a motor? Isn't it just a high/low voltage signal?

Thanks,

Jim

[Al_The_Man]

Its a job to tell, but it looks like there maybe quite a bit of interconnection between the Digiset and the control.
The servo circuit works by sensing the minus arc voltage and it responds to changes in the voltage to maintain the gap, so it can control velocity and polarity to the servo to control speed and change direction. The servo valve amp usually has ±15v transistor output for this purpose.
Al.

[mdynac]

Converting your machine from hydraulic servo system to dc servo motor or stepper motor system would not be terribly difficult, however if the only complaint is that the pump is too noisy, consider yourself lucky.

I repair, modify and design upgrades for all EDM machines, and of course i could put a dc servo system on your old elox, but assuming that your hydraulics are not leaking(bad cylinder seals) or the moog valve isn't shot, i see no reason to do it. Unless the noise is unbearable!!!! Personally I would run that puppy until one of the above situations occurs and then buy a newer one, or then set it up with dc servos....
However i would like to take a look at the documentation that you have (schematics, etc) on the servo motor upgrade that you mentioned....we could possibly do a "quick and dirty" upgrade if the info is good.

If not and you still want to upgrade you are looking at , the following hardware, a servo motor, an analog servo motor driver(Copley Controls, about 300 bucks or so) and some assorted gap sensing and pulsating circuitry. Probably around 2 grand or less, plus installation of course.

I work almost exclusively thru EDM Network up in Sugar Grove Illinois. (check out edmnetwork.com) They refurb used edms and sell a new line of Chmer edm's. and I am always available for consulting on older machines.

hope this helps,
michael

[mdynac]

one more thing,

I'm sure that the Fagor DRO has an "EDM Mode" so it won't be too
hard to interface it with your existing electronics, it is just a bit difficult to do it without me being at the machine!!!!!
I'm sure we can get you up and running, no matter which way you decide to go.....

michael