Re: CNC Welding, Any Real Experience Out There?

Ray, thanks for the info...

> weld was straying to close to that side, and would adjust itself

closer

> to the other side.

Very impressive and makes good sense, I personally don't have
detailed knowledge of how mig systems control the arc, it sounds like
its predominantly via current, and perhaps some combination of
both??? Initially, I intend to only use open-loop mechanical control
in terms of tracking the seam, height, etc. In other words, all
motion control will rely exclusively on the contents of the g-code
without any feedback. I would like to learn `more' about how the
commercial machines are controlled and implement ideas as my
knowledge grows. Do you, or anyone else have any good links where I
can learn more about automated mig control?

> you have enough jobs to do, just skip trying to CNC it, and GO

ROBOTIC!

What do mean exactly by "ROBOTIC", robotic arm or?

The machine I envisioned was a long horizontal axis carrying a short
horizontal axis, which itself may include a third short axis for
height control.

Thanks, Eric





--- In CAD_CAM_EDM_DRO@yahoogroups.com, Raymond Heckert <jnr@a...>
wrote:

> In August of '01, the company I was working for sent two of us to

the

> Lincoln Electric School in Cleveland to learn to operate their FANUC
> i120 (or was it iL120?) based robotic welding system. We learned
> programming via the pendant, and using various techniques. The most
> impressive was TAST (Through-the-Arc Seam Tracking). This process

would

> track the current at either side of the weave, and 'know' that the

side

> that had higher-than-average current meant that the center of the

fillet

> weld was straying to close to that side, and would adjust itself

closer

> to the other side. You could program to weld a fillet 4 ft long in

the

> horizontal position, then lift the finish-end 4 or 5 inches, and

after

> starting at the prescribed point, the 'bot' would track the now-

inclined

> path exactly! At the time, we had ordered their biggest (except for

the

> gantry unit) i120 with a special 4th axis that allowed us to weld a

45"

> dia x 6 ft long 1300 lb water-tight water-heating furnace. My

advice, if

> you have enough jobs to do, just skip trying to CNC it, and GO

ROBOTIC!

> List Mom; is talk about robotics legitimate on your CNC list? Do you
> know if EMC has robotic capabilities?
>
> RayHex
>
> P.S. Lincoln's programmable Weld-Power supplies are outa this world!
>
> pondindustrial wrote:
> >
> > Hi all,
> >
> > This is my first post on this group and I'll have to admit the

recent

> > post regarding CNC welding caught my eye. Has anyone in this group
> > had any hands on experience with CNC welding? I have a Miller 251

mig

> > welder and once have rigged the gun to my CNC plasma table to weld
> > pipe and the results were impressive! I'm getting ready to fab a

full

> > scale "Straight Welder" (as I call it) to weld anything requiring
> > nearly straight welds. It will consist of a long axis about 7' in
> > length and a cross, or weave axis that will be conveyed by the 7'
> > axis. This axis will perform the weave motion and will compensate

for

> > any error in linearity of the metal to be welded.
> >
> > If anyone has any links, advice, or experience to share regarding
> > this project it would be greatly appreciated!