Plasma jig

[Trollhole]

Got tired of paying people to cut my carb conversion parts out and charging me an arm and a leg. So I bought a Giant Tech plasma cutter because, well, cutting a bunch of parts out on the bandsaw sucked.

So I need to cut out or rough cut out small parts with it and then finish then with a grinder or cutoff wheel. Thought about freehanding the parts but that seems to much and not very precise. Has any made a jig to cut out parts that works pretty well? I'm cutting 12ga sheetmetal. Any tips on making fairly clean cuts?

 

[LukeZero]

It sorta works for me- but here's what I did.

I cut out some patterns on that magnetic sign stuff you see on the side of electrician and plumbing trucks. You know the 1/8" thick stuff you can cut with scissors. Cut out the patterns 1/4" smaller than what I really wanted because that is the radius of the cutting nozzle on my plasma cutter. Just follow around the pattern. Having it magnetic helped to hold it in place.

Hint: Don't do a bunch of pieces all in a row. The pattern starts to melt from being next to the torch.

I'd be open to better suggestions because I'm sure this is not the best way of doing this.

 

[Trollhole]

I thought I would cut a piece out of 1/4 steel with a magnet in the bottom of it. Though something tells me there is a better way.

What about using a pantograph?

 

[rusty_tlc]

The perfect accesory to a plasma torch.
TorchMate 2X2

 

[Trollhole]

The perfect accesory to a plasma torch.
TorchMate 2X2

Yeah I looked at that first. An awesome machine. Wish it would do product about a foot longer. Then I could just CNC out soft top bows as well as cut sheetmetal. It will take me a while to sell enough carbs to buy that.

 

[nicholastheczar]

Let us know how you like your plasma cutter. How it holds up, consumables, etc.

Nick

 

[Arya Ebrahimi]

Cut the piece out of masonite(particle/chip board) while accounting for the offset of the cutting head of the torch. Using a metallic template will sometimes cause the arc to short circuit through the side of the nozzle and ruin the tip.

 

[jimcolt]

If you have a shielded plasma torch (has a copper shield that double insulates the nozzle) you can use metal for a template. Here is a pic of my Hypertherm Powermax 45 drag cutting with a guide. Hypertherm invented shielded torch technology...this allows you to drag cut at up to 200 Amps.
Jim Colt

 

[scouthead]

Cut the piece out of masonite(particle/chip board) while accounting for the offset of the cutting head of the torch. Using a metallic template will sometimes cause the arc to short circuit through the side of the nozzle and ruin the tip.

Yeah, I make patterns out of Masonite also... Can use them a few times before they get messed up. I would like to find something more heat resistant, but Masonite is easy to work with.

 

[e9999]

a side question, but I dare since you are all experts here and it's a good spot:

how come I see the guys on Extreme 4x4 always cut stuff with a plasma torch when the plate is sitting on a metal table with a mesh top? The mesh doesn't get cut too?

 

[jimcolt]

If they use mesh (or expanded metal).....it will get cut through. Usually cutting beds on a cnc machine are slats that are mounted vertical (perpendicular to the plate)......depending on the power level of the plasma system, the slats may be 16 gauge x 2" wide.......or big industrial machines the slats can be 3/8" thick x 6 inches wide. These slats get notched a bit.......but don't get cut all the way through. I would attach a picture....but the system will not let me!

Jim Colt

 

[Mace]

1/4" plywood with the hole cut out. This way, you do not have to try and hold the center of the part and cut. You can hold the "frame" and cut inside the hole.

 

[Trollhole]

Okay so this is what I did.

Take my pattern. Put it over a peice of scrap 16ga sheet metal and cut it out with the plasma. Now I have a template for my parts using the 16ga pattern I just cut. Used a die grinder to smooth it up and a bit of sandpaper. Now I can cut parts in seconds.

 

[rusty_tlc]

GP03 is a material I use for assembly jigs

McMaster-Carr

It tolerates fairly high temps and is pretty tough. They claim 284F but I take it higher in some applications. It is easy to machine with standard wood working tools, table saw, band saw etc.