Re: [CAD_CAM_EDM_DRO] Re: SQUARE WAVE TIG

Lee, what you have is a MIG with a conversion kit for aluminum. Probably has a teflon liner for the gun, and a soft roller for
the feed. (and you do have to use argon.)
I made the same mistake with my hobart (long time ago).. Wire feed aluminum setups don't work well at all, for several reasons
but mainly because you can't control your fill metal and your heat independantly. The aluminum wire is soft and buckles easy, you
have to use a big diameter wire and put a LOT of heat in. This is why spool guns have very short wire run.
Try pre-heating your parts to about 300-350 degrees F and then weld them. This is the only way I ever got acceptable results
with my Al wire. I NEVER use it.
The power supply for MIG is very different than TIG and Stick. They are not compatible processes. You can buy a "Universal
Machine" that supports MIG/TIG/SMAW, but they are expensive, big, and a pain in the butt to switch between the different systems.

Lee Studley wrote:

> When I bought the MillerMatic 175 Mig unit, I was sucked in by
> the claim that it would also do aluminum well.So I got the argon
> shielding bottle/gas too.
>
> There must be some trick to it that I havn't figured out, as all I've
> done to date, is ruin tips and make 'ok' looking joints with no
> penetration, so when you hit it with a hammer, the weld pulls off
> like a bad glue job. I played with polarity and every setting I could
> control, no luck.
>
> I've got schematics for the square wave tig (from the manual), but
> it doesnt go into the SCR controller details, just the main xformer
> etc. Also, the SCR's and parts are not cheap.
>
> -Lee
>
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