Re: [CAD_CAM_EDM_DRO] A bit off topic - resistance welding

Hi Ian,

OK, just a thought as I'm not that versed in such things, but if you
were to examine a "spot welder", (from what I recall) you would find a
low voltage transformer, and a pair of electrodes to tightly hold the
parts, and then a HUGE current caused to flow. 'Been a long time, but I
thought the electrodes were copper. You're looking for HEATING, not
ARCS. I couldn't say for sure, but I'll bet you could run A.C. to the
electrodes, and not rectify it. You certainly don't need the filter
cap, as I don't think the idea is to "spark" like EDM. Again, I could
be wrong. I'd go for a LOW voltage, and HIGH current (5v and 40A?).

Anyone care to EXPAND (or CORRECT)!

Alan

Ian Wright wrote:

>
> Hi,
>
> I know this is a bit off topic but I know you lot out there have all the
> expertise in the world!
>
> Does anyone have any idea whether it would be possible to make a simple
> resistance welding set-up for tiny jobs? Basically what I am wanting is a
> way of spot welding bits of watch or small clock mainspring material
> together - spring steel up to about 15 thou thick with welds probably about
> 1.64" diameter. I was thinking it might be possible using just a big power
> supply and capacitor like in EDM and discharge this through some kind of
> 'clip' but I'm not sure how to control the discharge (SCR, Triac?) Also I'm
> not sure about the voltage/current needed - a 24 volt, 10 Amp transformer
> with a bridge rectifier and 10,000uf capacitor seems to give an impressive
> spark but would this be enough to weld my bits of steel or is it only good
> at screwdriver blades? ;o)
>
> Any comments would be appreciated.
>
> Ian
> --
> Ian W. Wright
> Sheffield UK
>
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