Backstepping

[ANDY P.]

This may be a totally obvious question, but oh well. What exactly is backstepping and what are the applications which require it?

[vicegrip]

Hoping for some Pro-answers to this one.

I can say what "I" think it is , and when / why I do it.
BUT accurate or propper ??

Making machine frames, in the 90's, I had lots of welds,
of dissimilar thichnesses, and even different steels.

I liked to move ahead at one rate (the welder had two trigger positions)
with independant setting-knobs, and then back-up at the lighter seetings
to broaden the bead, and saturate the weld area with lots of heat.

This seamed to leave a less intence HAZ around the welds,
and things didn't end up cracking, in two years or so.

????

vg

[araspitfire]

I thought back-stepping is moving from left to right, while welding right to left...

Start near the 'end' of your total weld... Make a short run from right to left... Then move to the right and do another, joining up with your last run at its beginning.

The purpose being to control total heat buildup and avoid excess warpage....

Al...

[DannyK]

Weld 1________Weld 2________Weld 3
<------------- <------------- <-------------

[ANDY P.]

Thanks for the replies... I get it now and also now remember reading about that for warpage/burn through control. I was a bit confused because I remember reading about another technique with wire welding where you repeatedly move your arc back to the center of the puddle then back to the leading edge as you progress along with your bead. If I remember this correctly, what is this technique called and for what purpose would it be performed?

[Sberry]

pictures, a version of it. These were getting sawed in pieces so it was not real critical.

[ANDY P.]

Do you not use a back hand motion for this?

[ANDY P.]

Never mind that, I was looking at it wrong....

[383IROC]

It is explained in this video at the 4 minute mark.

http://video.google.com/videoplay?docid=2761179198296053547&hl=en

[ANDY P.]

Thanks, that's guys got some pretty informative stuff.... I just found the link to his other videos earlier today.

[Sberry]

The machine doesnt know right to left or left to right.