Re: [CAD_CAM_EDM_DRO] Sizing Cap's ( was Re: Photoflash capacitors for EDM use

turbulatordude wrote:

>Hi Guys,
>
>I am amased at the range of caps being used.
>
>Jon works well with 1-3uF, Langolis shoots for stages of 50uF up to
>400uF in his bank. And Richard says his does not see much difference.
>
>I was under the impression from Langolis that WORK = Joules deliverd
>and that 0.5 times capatance times voltage squared = joules
>joules = 0.5 x C x V^2
>
>I guess that hunt for a 1 farad cap is over. (actually on e-bay for
>$50.00)
>
>So, if the cap size does not make a world of difference, where's the
>power come from ?
>
>

Well, it depends on EDM fluid, electrode and workpiece material, and
what you are trying to
accomplish. I have experience only in burning out taps, without
wrecking the threads in
the part. So, I wanted very small sparks so as not to blast everything
to bits. it may be for
other purposes, you'd want some different settings. I was also running
at 30 - 50 V. With
water as the fluid, you might want to run more capacitance at lower
voltage. One thing,
with smaller caps, you get more discharges/second. When things were
running right
(which was hard to achieve) it sizzled quite nicely, hundreds of sparks
a second.

Jon