View Full Version : Mach3 and EDM. Has anyone written macros?


neilw20
09-30-2008, 11:32 AM
With the flexibility available on Mach3, like controlling the machine for an Auto Tool Zero Setter, I am sure it can be adapted for EDM use.

The above Auto Tool Zero Setter:
http://www.cnczone.com/forums/showthread.php?t=36099&highlight=greolt

Has anyone used Mach3 for EDM control?

I broke an M4 tap in stainless the other day and had to visit a friend to get him to use his EDM sinker to remove the offending tap.

Watching the process, I am sure Mach3 can be adapted to this task.

Al_The_Man
09-30-2008, 11:50 AM
An EDM can be used of course to remove broken taps, But if making one from scratch, rather than retro-fitting an existing one, a Tap Disintegrator is a simpler machine.
The EDM requires a more sophisticated DC power supply, with usually PWM control, a Tap Disintegrator uses a simple low voltage, high current AC source, and usually the electrode advance is produced by an AC vibrator. No servo's needed.
For pursuing the EDM approach, there is an excellent DIY book written by Canadian Robert Langlois Published by the HSM, entitled Build An EDM.
This gives the fundamentals needed and the design of a small practical machine.
I am not sure if you can get this down under?
Al.

neilw20
09-30-2008, 12:03 PM
I just used my tap as an example. Sorry to mislead.
Yes, EDM requires a more sophisticated DC power supply, with usually PWM control.

The question was has anyone used Mach3 to control such a machine.

The fancy power supply is no more complex than a servo drive, all be it quite different.

neilw20
10-03-2008, 03:09 PM
EDM. Mach3. Anyone?

neilw20
10-10-2008, 11:16 AM
Anyone need Mach3 EDM?

Mongkol
10-10-2008, 01:08 PM
Hi Neilw,:)
It's very interesting. Can Mach3 control EDM machine? Do you have more detail? I am interested in doing EDM-homehobby machine.

Mongkol

neilw20
10-10-2008, 01:31 PM
You can write external cycles, in VB modules such as using a probe for auto z-height setting where a cycle is initiated to move z down until a probe touch, then retract a controlled amount, (like an EDM needs) and rezeroing the Z DRO.
You just need to make it into a cycle you can call with a final Z depth for example, and it can hunt up and down until the destination is reached, via a few control loops.
Then it can retract like you would with a drill cycle and move to the next location.

Doing EDM wire would be a bit more involved, but the same principle applies.
You are just creating a vector, and a controlled way to get there with feedback from an external signal (the spark current control).

You would just write code like a drill cycle. Because Mach3 can control 6 axis more complex functions with U and V drives are possible.

Al_The_Man
10-10-2008, 01:47 PM
I suspect the issues to overcome would be Hardware rather than software.
In pre-CNC sinker EDM machines, the profile was formed by a highly conductive die material, and Hyd. servo valves used a simple closed loop system to control the arc gap, as done with steppers in the Langlois book.
In the case of CNC, the servo's have to be constantly controlled under arc voltage feed-back control until the profile is reached.
i.e. A profile move is not performed as in a normal CNC move.
Steppers, as with servo's have to be constantly incremented/decremented as the arc voltage dictates.
Al.

neilw20
10-10-2008, 03:29 PM
A modified version of the the following techniques will work.
http://www.cnczone.com/forums/showthread.php?t=56079
As long as Mach3 stays in the canned cycle until the end of the burn the VB logic can take care of all of the control.
Just say where you want to burn and how deep.
On a vector by vector basis.
Mach3, from within a VB loop can move any axis according to whatever logic you can invent. Stay in the loop until the burn is finished, or the abort button is hit.

jemmyell
10-10-2008, 04:22 PM
Have a look at plugins. If it can't be done completely in VB then you can certainly do it in a plugin.

I posted a plugin tutorial at the machsupport forum:

http://www.machsupport.com/forum/index.php/topic,4884.0.html

-James Leonard