wire EDM pedestals: when to regrind

Hi All:
I need to know at what point the pedestals on a wire EDM should be re-ground to make them flat again.
I just got a used machine, and they look pretty worn to me.
Have any of you mapped yours with a dial indicator to see how flat they are when new?
Cheers

Marcus

Hi Marcus

Ive had a Sodick from new 10years ago and it is still pretty darn flat but far from mirror like due to lots of minor scratchs and I also use Hirschmann macro tooling for 80% of work which doesnt touch the table at all.

Some table are made out of softer stainless than others, might be worth a call to manufacturer to find out what is involved and maybe cheaper to purchase some adjustable tooling depending on the type of work you expect to be doing.

A smooth stone and a drop of duck oil is all i use to clean up sometimes.

Cheers Kev

You didn't mention which machine you have. Not that its all that important.

Just depends on your work and your work holding. The pedestals don't wear per se, but will get the occasional nick or bump which usually just gets stoned off. Pedestals I was familiar with were well within .00005" everywhere when new, and I was a service rep so I saw a lot of machines...

If you have to regrind them, you'll want to reset (or at least check) your lower guide height in the control to maintain taper accuracy.

Wire EDM pedestals

Hi Kev and Hollistergc:
Thanks for your replies; they're very helpful.
I just took delivery of the machine, it hasn't been hooked up yet.
When I saw the condition of the pedestals, I took an indicator and put it on a surface gauge, then ran it all over the pedestal surfaces.
It seems to have some pretty major humps and hollows...up to 0.0015" in the worst places.
I know this is a very poor way to judge the table flatness, so I'm suspending judgement until the machine has power and I can map the table properly with an indicator.
The machine is a Sodick A 320, vintage 1995.
If the table needs to be reground, I'll need to negotiate the cost with the seller.
There's no way the machine is anywhere close to half a tenth for table flatness...I can feel the humps where the mounting screws were reefed down and the wear patterns are pretty easily noticeable under a light.
I can also make a parallel rock a couple of thou in some places.

Thanks again for the information.
Cheers

Marcus

Hi Marcus

My Sodick is A320d EX21 with AWT and bought it new in 1996 when we first started up , so if i can help with any Qs just post away .

Cheers Kev

Thanks for the offer

Hi Kev:
That's a very generous offer.
Thank you, I'll probably take need to take you up on it more than once.
The technician is supposed to arrive this coming week to install the re-ground pedestals and sort out a few other little gremlins, and then it's time to try to re-learn all I was taught when I took the training in June.
Mine's not an AWT model...I opted to get a W axis (fully interpolating rotary axis) instead.
I do lots of fussy intricate prototyping; the W axis will get lots of use in my shop.
I've got work already lined up for it...it's going to be fun learning the tricks of the new toy and finally starting to make some money on it.
Cheers

Marcus