CNC TIG Welding

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msimpson
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Posts: 3176
Joined: Tue Mar 30, 2004 6:19 pm

CNC TIG Welding

Post by msimpson »

While doing research for a "Building a Plasma Cutter CNC" workbook, I started experimenting with using one of my CNC machines to do some fusion welding.

The biggest challenges was the shielding. The HF start on the TIG welder causes some major EMF spikes in any cable that is near the TIG torch or welder. I had to run all the cables in a conduit to the PC. In addition all wires and cables going from the motors and switches to the conduit box were enclosed in steel braded sleeves.

All cable connected to the PC (includes monitor, keyboard, mouse, power) had a ferrite core added.


I now have a 99% error free job start. One of the worst offenders was the parallel port cable on the PC. Seems a lot of the false signals and spikes come in through this. I actually had to put two cores on the parallel port cable (one on both ends). They helped a lot. Before the cores, I had a 1% error free job start. The HF arc start on the welder would force the software into a restart mode.

I don't get 100% because the PC itself gets some interference via line of site to the torch head. If I stand between the CNC and the computer it works 100% of the time. If I don't, the failure rate goes up.

There are a few things I have yet to do on the PC side. The simplest is to build a shield out of grounded aluminum screening.
The other is to drop the parallel port and move to the Ethernet SmoothSTepper. This eliminates all the parallel port interference issues.

Here is a vid of the welding process.


The G-code was written by hand.
msimpson
Site Admin
Posts: 3176
Joined: Tue Mar 30, 2004 6:19 pm

Re: CNC TIG Welding

Post by msimpson »

I did another video. On this one I did a fillet weld. Worked very nice.

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