Re: [CAD_CAM_EDM_DRO] Re: Brand new to the group

Richard wrote:

> Jon, In message #14380 I was referring to the 'Langlois' EDM machine
> which I am using. And it works like a gem.
> The spark is moving all the time. The stepper motor moves the
> electrode away from the work when the 'gap' voltage falls below a
> preset value,and toward the work when the voltage rises to another
> preset value. This is controlled by the use of a window comparator
> plus the other necessary logic circuitry needed to drive the stepper.
>
> The problem in this case is the relatively slow response time of the
> stepper and the screw setup which moves the electrode. It is not in
> the order of microseconds.

Yes, this is so slow as to be inconceivable. I get several hundred
zaps a second with the resistor/cap circuit.

> There is one other feature in the Langlois machine which gives a
> rough control of the rep rate of the charge/discharge system in that
> you can choose several capacitor values (time constant).

Yes, I have that, too.

> Yes, you are right in what you said regarding pulse width means of
> spark control but I don't think it would be an easy change for me to
> make on my unit. Thanks for the response. Richard

Well, I'll have to try it sometime, because what I have now is too slow.

Jon