Are you inspecting your welds by sawing a sample piece in half so you can see the profile? You need to insure that the penitration and HAZ is proper? It is very easy to make a really nice looking but complelty useless bead with an automated welder.

Yes I have and am getting good penetration.   I have read that you set these up(real ones anyways).   is there any data on feed rates?  I just guessed until I got it right.   It seems as thou you could up the wire speed in proportion to travel speed... is this right?

Thanks

Tom

I used to do automated welding/cutting. For the last seven years I have been building test and automation equipment for a local university.

You can find a starting point by using a welding 'calculator' like Miller Electric Part # 086446 . It is slide rule type device that will give you a good starting point with a given material thickness, wire, gas, etc. There are so many combinations of base materials, wire, etc that it takes some experimentation to get it right. You might also be able to find some more info on MIller's website: http://www.millerwelds.com/education/articles/articles10.html.

This is a photo of the seam welding rig we use. It is basically little more than a cannibalised MIG set with the wire feed and torch put on a motorised, track-riding carriage. Welding current and control signals are fed to it via an umbillical cable which is supported along a clothesline over the track. It's seriously dumb and ugly.



All it does is ride along at a fixed speed, with the current and wire speed constant. All settings are adjustable of course, but there's really nothing clever about it. It is designed to weld up to 4m in one shot, for making spinning blanks for satellite communications "dish" antennas, which usually means we're welding 1050 soft sheet with 1050 filler wire, real chewy stuff.

The clamping jaws have copper bars in them for chilling the weld and preventing distortion, and there's a copper plate with a channel under the weld line so that the molten bead can flow down.

Penetration is 100%, weld quality is excellent and distortion is negligible - For starting and stopping, we just do it on a bit of scrap at each end, lead in and lead out.

I'm sure a half-decent CNC rig could do a very nice job of welding - use the coolant trigger for gas, and you can control pre and post flow, dwell to build up weld at start and finish, and if your welder won't accept a digital input you could do worse than stick a small stepper on the current knob and call it an axis... set your wire feed up controlled by Mach3 as a spindle... More than one way to skin a cat, and I reckon there's real potential here.