Since some have suggested carbon electrodes you might try .3mm or .5mm
mechanical pencil leads. I have no way of knowing if they would be
appropriate,but might be worth a try. You should be able to find .3mm
leads at an art or architectural supply store.
--- In Homebrew_PCBs@yahoogroups.com, roger lucas <ralucas4277@...> wrote:
>
> Hi Stefan,
>
> I know that it should have worked in theory, but I was
> surprised at how well it actually turned out.
>
> I tried with tinned copper wire and a tinned steel
> sewing needle (purloined from my wife's needlework
> box), essentially the wear was about the same for
> both. The eroded pixel diameter is directly related to
> the electrode dia, as the sewing needle eroded the
> pixel became larger.
> I need to try to obtain some half hard or hard 10 mil
> brass wire for the next trial.
>
> The setting of the spark parameters before sparking is
> essentially to eliminate the uncertainty of whether
> pixels have been fully eroded or not, especially where
> electrode wear is high. I might just try some broken
> carbide drill bits, the tungsten might resist erosion
> better, trouble is carbide only goes to 0.5mm dia.
>
> Will post some sample photos after next revision and
> trials.
>
> Roger
>
> --- Stefan Trethan <stefan_trethan@...> wrote:
>
> > Good to hear you got such good results.
> >
> > I don't have any specific concerns why it would not
> > work, never had after
> > some manual tests with a simple power supply.
> >
> > But i don't currently have the time to build a CNC,
> > although i have most
> > components set aside for a while now.
> >
> > The electrode erosion thing was discussed back then,
> > if i remember
> > correctly the thinking was that one would advance
> > the electrode until a
> > spark of the correct voltage is occuring. One would
> > need to decide if the
> > energy was sufficient to blast out the pixel or if
> > it must be re-done.
> > But your approach seems a good idea also.
> >
> > Keep us updated, i definitely plan to build the CNC
> > but it will be months
> > for sure. If i use it for drilling of inkjet printed
> > PCBs or if EDM will
> > be an option is to be seen.
> >
> > what material is your electrode wire made of?
> >
> > ST
> >
> >
> > On Tue, 02 May 2006 18:07:19 +0200, roger lucas
> > <ralucas4277@...>
> > wrote:
> >
> > > Well, I finally motivated myself this holiday
> > weekend
>
>
>
>
>
>
> ___________________________________________________________
> Win tickets to the 2006 FIFA World Cup Germany with Yahoo!
Messenger. http://advision.webevents.yahoo.com/fifaworldcup_uk/
>