Plasma issue...

[mrcaptainbob]

I need some help. I am ignorant of the technique of using a plasma torch. I recently purchased a CUT-40, 40 Amp Plasma Cutter DC Inverter 120/240V Dual Voltage Cutting Machine. The claim is that it easily cuts 1/2" steel. Here's a picture of today's effort. The screw is the pivot, the top-most hole is for the torch tip and shows the arc that I'd like to cut. I am not pleased with the results. Either me, the machine or both. Any suggestions?

 

[mrcaptainbob]

Here's the picture...

 

[Big Barn]

You will get more qualified advice from others but when you do, definitely practice cuts on a piece of scrap until you get it figured out.

 

[boomer1025]

You Should have drilled a hole in the piece your trying to cut instead of trying to blow a hole with the Plasma Torch.
Start cutting from the hole. Cutting 1/2 inch with a 40 amp unit will be slow going but doable.
When starting a cut that's not on the edge on heavy metal drill a hole first if possible. On thin metal the torch will blow through to start the cut.

 

[Industrial Toys]

Looks like one of those ancient star maps! You have some talent for sure.

If I go to wreck something, I make perfect cuts.

Generally speaking, if I seek perfection (which I usually do) it turns into a dogs breakfast.

 

[TractorGuy]

What voltage are you plugged into? What is your amp setting? What do you have your air pressure set to?

I don't think you're gonna cut 1/2" with it connected to 120V.

I have a Cut50F with pilot arc and I've found almost everything except real thin stuff cuts best on full power and air pressure set to 60 PSI. Mine is 240V only.

 

[RNeumann]

As stated above- practice and start on an edge. Center punching is a little more advanced- something you can learn after a few good cuts that start on an edge.

 

[mrcaptainbob]

It's on a 240V circuit, amps was set at max (41 was the display reading...), air was set to machine max 60psi. I did practice some on both thin gauge and thick. The very first cut was on 1/2" diamond plate. It went so well I was ecstatic! two projects I have require this, but it's actually rare I work with anything that thick. The lead in on the practice was from the edge. I did consider that and drilled a starter hole in the good piece. Sparks flew from beneath and I was happy. Until....well, it all got snotted up. I should redefine what I'm doing maybe. I'll call all I'm doing on the good stuff as 'practice'. Maybe THAT would work! Seriousness aside...was the torch speed too fast? I'll try it again tomorrow, but hopes aren't there anymore.

 

[Big Barn]

Not saying this is the problem, but I usually need to grind a shiny spot for the work (ground) clamp.

If you need to pierce a hole, start with the torch angled and bring slowly to the full upright position as the cut blows through to prevent blowback and making a mess of your torch and tip.

Try another set of consumables in your torch.

 

[yomax4]

You are certainly on the outter edge of power trying to cut or pierce 1/2" with 40 amps. Actually piercing is really out of the question. You should be able to cut from and edge or as stated above, drill and start there. Slow going and a guide will surely help. Machines vary greatly in output. It's more about kilowatts than amps with plasma. Brands can say they have what ever they want for amp output but without the kilowatts the performance is less. This is why a Hypertherm power max 30 with good kilowatts will out cut many 40 amp competitors units. Just for grins, find a set of DC tongs and clamp on your ground cable while running 40 amps and see what the meter says. Might not be 40 amps

 

[mikester]

If you need to pierce and cut 1/2 regularly then you have the wrong machine for the job. Sorry but you are expecting a $300 machine to perform like a $3,000 machine...I wouldnt recommend buying tractors or tools like this at homedepot because all you get is cheap homeowner class junk.

You need to start with something like a hypertherm powemax 65 want clean cuts in 1/2 metal. You can do it with the model 45 but you need to slow down. In your photo you havent even gone through the metal and yet you are moving the torch...good if you like blowback and eating sparks.

 

[Rustyiron]

If your travel speed is too fast and your not blowing through and out the bottom side, you'll have these results.
Drill a hole inboard slightly of your desired cut and work out to it. When dealing with a "maxed out" power situation, you can't go too slow! Like BB suggested, a good ground and consumables are a must and although your pic shows a nice clean & new piece of material, if you cut that rusty "radius guide" prior to your attempt...... The consumables don't like rust, dirt or paint.

 

[metalbender]

You probably can't see what's happening with the cut using a guide like that. When I need to do circles, I use wood or aluminum piece of the correct thickness for the tip not to drag, use a hole saw for the size. Saved hrs of drilling when I built my land plane, hot drilled the many holes to mount the blades. Also in the set-up, how good is your air supply filtered?

 

[Big Barn]

If you need to pierce and cut 1/2 regularly then you have the wrong machine for the job. Sorry but you are expecting a $300 machine to perform like a $3,000 machine...I wouldnt recommend buying tractors or tools like this at homedepot because all you get is cheap homeowner class junk.

You need to start with something like a hypertherm powemax 65 want clean cuts in 1/2 metal. You can do it with the model 45 but you need to slow down. In your photo you havent even gone through the metal and yet you are moving the torch...good if you like blowback and eating sparks.

Using this machine the OP mentioned that he has already cut 1/2” diamond plate with success.

While Hypertherm is somewhat the “gold standard of plasmas” his Cut 40 is far from a $300 machine and has good reviews from many users.

 

[shaeff]

I cut 1/2” plate with no issues on my Hypertherm Powermax 45.

Looks to me that if the amperage was cranked, air pressure was in spec, and a good ground- your travel speed was too fast.

 

[Big Barn]

Most likely as others have mentioned starting from an edge or a drilled hole would have been better. The poor radius cutting guide also contributed to its failure.

Good chance blowback ruined the tip and electrode and both may need to be replaced.

 

[downsizingnow48]

I looked up the CUT40 manual. It says 3/8 material max. Also - and unlike the Hypertherm torches - you cannot just drag the nozzle along the work. You have to keep the correct space between nozzle and work. So there are two more possible things to consider.

 

[Big Barn]

I don’t know about Hypertherm, but I don’t drag on 1/2” material with my Miller 625 Extreme.

 

[Big Barn]

Using this machine the OP mentioned that he has already cut 1/2” diamond plate with success.

While Hypertherm is somewhat the “gold standard of plasmas” his Cut 40 is far from a $300 machine and has good reviews from many users.

Okay I had to quote myself to correct my error.

I now realize the OP’s Cut 40 is an Eastwood product. I mistakenly thought it was a Victor/ Thermal Dynamics Cutmaster 40!


My apologies to everyone. I need to read a little more carefully.

 

[yomax4]

Okay I had to quote myself to correct my error.

I now realize the OP’s Cut 40 is an Eastwood product. I mistakenly thought it was a Victor/ Thermal Dynamics Cutmaster 40!


My apologies to everyone. I need to read a little more carefully.

Victor Cutmaster 42 will cut 1/2" pretty well but would struggle to pierce. Not quite like the Powermax 45 will though. Back to the Killowatt thing again. I have a 42 and enjoy the low air consumption compared to my 82.