Re: EDM home brew units ?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "agerooo12000"
<agerooo12000@y...> wrote:

>
> > I think the real next phase is more electronics and more actual
> > control over the spark, (Warp Drive an not Impuse engines) not just
> a
> > larger transformer.
> >
> >
> > Dave
> >
>
> That is where my interest lies. I'm just on the wrong side of the
> electronic curve. I'm still thinking in mechanical terms of ICs as
> building blocks that work together similarly to any other mechanical
> system. ie. motor to transmission to universal, to movement. Timer
> chip to 4017 to transistor, to LED array. I know just enough ohms
> law to be dangerous. I also figured that a 20a power supply would
> make more waste heat than swarf if I kept with the RC circuit.
>
> Langlois talked about experimenting with cross shot astable times for
> duty cycles, but doing further research, I found out that at anything
> over 1kz the system becomes unstable (what I've read, not first hand
> experience). This brings up the questions:
>
> Is (up to) 1kz good enough, or do I want to pursue higher frequencies?
>
> If I want to pursue higher frequency duty cycles, where is a good
> place to look for circuits?
>
> With a modern duty cycle circuit, is 20a over kill? If not, is there
> a rule of thumb regarding amps to square inches of graphite?
>
> Thanks,
>
> Bill

There is a formual that relates surface area to amps. more amps
allows a larger surface area. more amps in a smaller area does not
offer any benifits.

At some point, you no longer spark, but arc and then the process is lost.

An active circuit to charge and spark is desired. no reason why one
could not have 3 caps, each discharging in a round robbin fashion
while the others are being charged.


Dave

>
> Wait til you hear all the driver questions I have for a "cheap" home
> brew mini mill. Mechanicals are a snap... 12" x 8" x 2"
> capability... <--- Quick, get a camera. The boy is out of his cage.
>