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Why The Wobble?

Posted: Fri Apr 09, 2021 8:13 pm
by Toggatug
Just a weird curiousity question, does anyone know why parts would wobble/vibrate sorta thing when I light up on them?

Doesn't happen all the time but every now and again when I light up the part starts moving on its own accord sometimes bad enough to jump at the tungsten.

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Re: Why The Wobble?

Posted: Fri Apr 09, 2021 9:25 pm
by Spartan
Toggatug wrote:Just a weird curiousity question, does anyone know why parts would wobble/vibrate sorta thing when I light up on them?

Doesn't happen all the time but every now and again when I light up the part starts moving on its own accord sometimes bad enough to jump at the tungsten.

Sent from my Pixel 3a using Tapatalk
I believe it is the result of electromagnetic flux acting on the part as a circuit is formed. The same thing that contributes to arc blow when stick welding, your filler rod occasionally sticking to the work piece (away from the weld area) when TIG welding, and grinding dust occasionally forming flux lines around your leads on the floor. We are often times creating large and powerful electromagnets when we are welding.

Re: Why The Wobble?

Posted: Sat Apr 10, 2021 12:37 am
by tweake
worse thing is any shavings laying around go flying into your tungsten.
for the part, if its that light and loose then use a third hand or clamp to hold them down.

Re: Why The Wobble?

Posted: Sun Apr 11, 2021 12:33 pm
by Toggatug
Spartan, I never would've thought of magnetic fields but makes sense to me, my best guess was it was the force from an arc strike when the part finds it's ground on my not so pristine table.


And tweake, I find it odd that it's not usually the lighter parts I weld that get the wobble that keeps going.

Last one I recall was a tank for a cooler, 1/4" thick ally that was 4 1/2" x12" then 5" deep. Seems like the parts about that size get more momentum behind them or something.



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Re: Why The Wobble?

Posted: Sun Apr 11, 2021 12:56 pm
by G-ManBart
There could also be some simple harmonics going on...the arc has a frequency and so does everything else so it just requires the right combination to have things dance around.