Another Quickie Plasma Compass

[cutter]

and another cheap-like-me rig to get me through my next project.
I needed to be able to cut a reasonably round 16" disk out of some 1/8th" scrap. No way I can cut it freehand; I can't even maintain the tip distance, let alone follow the line.

1. So I assembled some parts; this was a really fast deal once I spent a day or two finding the pieces. What we have here is a cut-apart HF O/A torch roller guide, a Miller standoff or roller guide which I have never used successfully because I never have that wide a drop or an even surface to work with. And a sheetrock circle scoring tool. Oh - and a 24 inch long 1/4" rod. I thought I had a square bar but I never could find it so the round one had to do; that turned out to be best anyway.

2. I cut about an inch or threads on one end of the rod, added a jam nut and screwed it into one of the brass knuckes from the sawed-up HG standoff, replacing the thumbscrew.

3. Then the knuckle slips onto one of the roller guide posts on the Miller standoff. I only wanted one of the wheels fo this operation. Since the rod replaces the thumbscrew to hold the post in the brass knuckle, I tightened the rod, then snugged up the jamb nut.

4. This is how she looks.

5. So I cut my circle. Not perfect but good enough for my purposes and 100% better than my freehand circles.

[keenavv]

Why are you getting a partial cut with your plasma? Air pressure?

[cutter]

Naw, I had 80 pounds to the inlet, 65 psi on the internal regulator.
The cut has always been problematic with this little machine, keenavv. That's why I've b*tched about it so much. But last night it seemed to fade every place that I touched one of the slats in that catwalk grate.

[keenavv]

My Cutmaster 50 works best with a bare metal ground,no rust. Nice circle.

[Walker]

Cutter, I have been watching your posts about your plasma cutter for a while and must say that there is somthing wrong with it! In my opinion it needs to go back to a miller shop so that they can troubleshoot the thing, as there is no reason for a plasma cutter to operate so poorly working properly. So long as it has dry air (motorguard filter) and a good power supply it should sing right through that steel.
Sorry to poke an already sore spot,

Andy

[LeonS]

I have the same end product If I travel to fast w/my Spec.2050, never the less cool tool Cutter.
L*S

[digr]

Nice Cutter I am going to build one of those one of these days. I always use the torch but it would be nice to have one for the plasma.

[platypus20]

Cutter,

I made one about a years ago, to cut a 96" circle, welded a washer on the end of a coupling nut, with a hole big enough for the nozzle to stick through, made a pivot, the cut a piece of 3/8 all thread to fit between to get the right dimension, worked great, Weldcraft wanted about $350 for a circle jig that big, I think mine cost about $20.

Jack