Re: [CAD_CAM_EDM_DRO] Re: EDM machine

Hi there
Would an Precision Crystal oscillator at a 1.000 MHZ
work. A friend just gave me two more old surplus units
from Motorala. The first is an Frequency generator and
the other is an Frequency Counter which has the above
Oscillator. The Generator is in perfect working order
. The counter I have removed things from it and is no
longer working .

Thank you all for the replies

John
--- Ian Wright <Ian@...> wrote:

> Hi,
>
> The original design by Langloise used quite big caps
> and was a fairly simple
> and brutal machine. In one of the later articles (in
> HSM) he speculates on
> an 'improvement' which adds in frequency chopping
> and pulse width control to
> the spark. This allows much better control of the
> cutting and, at the same
> time, a reduction in the size of the capacitors.
> Whilst he gives a basic
> circuit for this addition which is an oscillator
> with control over the pulse
> frequency and on/off timing driving a couple of FETs
> in series with the
> spark electrode power feed (and can therefore be
> added into the basic
> machine after construction), he doesn't specify
> component values and says
> the design 'will be refined if there is enough
> interest shown'.
>
> This is basically the way I am intending to go
> although I may need to seek
> assistance with finalising this add-on circuit as my
> electronics skills
> leave a little to be desired.
>
> This whole basic design seems to be similar to
> commercial machines - as far
> as I can tell from looking at the
> instruction/servicing books for a couple
> and would seem to have potential for producing good
> clean parts - this,
> however, remains to be seen!
>
> So, to answer your question, a big capacitor will
> give a big, uncontrollable
> spark while a smaller one will give better control
> and better finish,
> particularly if combined with a chopped, frequency
> controlled supply.
>
> As to electrolytes, I have read a lot of literature,
> none of which seems to
> agree on the 'best' fliud. I have also tried
> hydrocarbons (Stoddart solvent)
> on a basic EDM and scared myself silly! So, I am
> inclined to go with one of
> two suggestions I have seen - either a mixture of
> water and antifreeze
> 50/50, or hydraulic fluid and completely cover the
> part being machined in a
> deep bath of the stuff.
> Ian
> --
> Ian W. Wright
> Sheffield UK
>
> ----- Original Message -----
> From: "marble here" <marble_h@...>
> To: <CAD_CAM_EDM_DRO@egroups.com>
> Sent: 31 October 2000 21:14
> Subject: Re: [CAD_CAM_EDM_DRO] Re: EDM machine
>
>
> > I my self am making his EDM I just started looking
> for
> > the caps Now are you saying the the should be
> lower
> > instead of 100ufX150volts . So if one used 50uf X
> XXv
> > would make a better spark
> >
>
>
>

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