Re: emc for wire edm control

[Ray Henry <rehenry-at-up.net>]

Marcel

I have done a bit of work here and with Roland Friestad planning for such a 
retrofit.  He has a two axis Agie wire EDM that is a few years beyond factory 
service.

We had planned to use an analog signal for wire current but your approach 
also sounds interesting.  This could simply be a voltage up signal 
optocoupled to a parport pin and read by tkio.

One way to achieve the reverse path is to simply record the positions of each 
axis for each motion loop.  This is how we ran the first backplotter.  The 
second plotter does the math to make a vector from a whole series of points.  

With a file like this, when the parport pin goes low/high the grapical 
interface could abort the running program, switch to mdi mode, and issues 
each point back in the recorded position file as a g0.  Repeat this until the 
pin clears.  Once cleared, we could restart the cut at the activeline when 
the short happened unless we crossed position into a previous block of code.  
If that happened we would need to decrement the activeline by 1 and restart 
there.  

Cutter comp may cause a few problems but a few tests with the backplotter 
should show a good approach here as well.

Ray


On Wednesday 12 March 2003 12:18 pm, Marcel wrote:
> Hi
> I want to know if its possible to change emc to control a two axis wire edm
> machine. A wire edm machine need to be able to go back when the cutting
> voltage is low (shorted) and only start to go back to the cutting direction
> when voltage is high Regards
> Marcel Gombault
>
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