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

Hello Ian,

Model Engineers Workshop magazine described a combination bandsaw blade
welder/spot welder that would appear to meet your requirements.
Unfortunately, I have just loaned out a stack of my MEW magazines, and all I
can tell you is the device was described in two consecutive issues somewhere
between issue 26 and issue 56. Give me a couple of days, and I can get the
correct issue numbers for you, if you are interested. The welder used a low
voltage secondary as described in other postings, with a timing device to
control the weld period.

Robert Grauman in Sunny Alberta

> 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