Plasma cutting - what am I doing wrong?

[Oldoak]

If your are not tripping the circuit breaker, I don't believe the extension cord is causing the problem. Keep in mind the distance the plasma torch tip is held to the metal being cut is just as important as the cutting speed as well as the correct pressure setting.

Just a side note. In an industrial setting, we had always found it was easier to make cleaner cuts on stainless steel and other alloys than it was on carbon steel with a plasma cutter.

 

[ovrszd]

Oldoak brings up a point not mentioned yet. I use a "Drag Tip". Somewhere I think I remember Mark saying he did too. That's why it's critical to have a smooth metal surface to drag on.

Miller offers a tip that is held off the metal. Then the distance mentioned is very important. No different than properly holding a torch tip.

 

[kevin37b]

Richard is spot on . If you were trimming that blade with the cutting edge still bolted up there is a layer of rust and a gap . A cutter does not like that , deflection of the arc . As said you need a water filter downstream where the air has cooled and will drop the moisture . They are the best tool in certain apps ,but not all .Just trying to help .

 

[dragoneggs]

I show my inadequacies without reserve.....

Well keep your pants on! :laughing:

 

[ovrszd]

Well keep your pants on! :laughing:

Anyone who hasn't made an imperfect cut with a Plasma Cutter has never used one!!!!

 

[sdef]

Here is a decent book to view with examples of cutting problems and resolutions: Plasma Cutting Handbook: Choosing Plasma Cutters, Shop Safely, Basic Operation, Cutting Procedures, Advanced Cutting Tips, CNC Plasma Cutters, Troubleshooting & Sample Projects: Eddie Paul, Jay Leno: 9781557885692: Amazon.com: Books I believe he also uses Hyper Therm.

I do not use a drag tip but understand those consumables can wear quickly.

My guess would be worn consumables, the 10 gauge extension cord or air that is not filtered properly. Plasmas are very touchy with air quality. I use this for mine connected directly to the plasma: Motor Guard M-3 1/4 NPT Submicronic Compressed Air Filter - Air Compressor Accessories - Amazon.com, along with a water trap immediately before this filter. And agree with a previous comment concerning air compressor heat impacting air quality.

 

[ovrszd]

I do not use a drag tip but understand those consumables can wear quickly.

QUOTE]

How do you guide your cut?

 

[dickfoster]

If your are not tripping the circuit breaker, I don't believe the extension cord is causing the problem. Keep in mind the distance the plasma torch tip is held to the metal being cut is just as important as the cutting speed as well as the correct pressure setting.

Just a side note. In an industrial setting, we had always found it was easier to make cleaner cuts on stainless steel and other alloys than it was on carbon steel with a plasma cutter.

Just so you know, an extension cord would not cause a circuit breaker to trip but it would reduce the voltage at the machine due to line drop so the power the machine had to operate with would be less. Breakers trip because too much current is being pulled from the circuit, not too little voltage being delivered.

 

[shaeff]

I have a Hypertherm Powermax 45 as well, though mine is the older model not the XP. Something is likely going on with your extension cord/voltage, or you've got moisture issues. My PM45 can sever two 1/2" plates stacked together. (sever is the key word, here). It's not pretty, but it gets it done, rust, scale, paint, doesn't matter.

Cutting speed, the quality of your tips, etc... all play a role in this as well. I run it off a dedicated circuit direct from the breaker panel, and have decent moisture control.

I had lots of issues cutting before I put the moisture control in. Just some things to think about.

Edit: also, I do always make sure I have a good, clean, shiny bare metal spot to ground to. 99% of the time my O/A torch is used to remove rusty nuts/bolts, not for cutting plate steel or the like.

Edit2: I should also note that when I say "rust", I don't mean scale. I mean surface rust. Plasma cutters don't like scaly rust. I usually bang it off with a hammer first and let 'er rip.

 

[ovrszd]

I have a Hypertherm Powermax 45 as well, though mine is the older model not the XP. Something is likely going on with your extension cord/voltage, or you've got moisture issues. My PM45 can sever two 1/2" plates stacked together. (sever is the key word, here). It's not pretty, but it gets it done, rust, scale, paint, doesn't matter.

Cutting speed, the quality of your tips, etc... all play a role in this as well. I run it off a dedicated circuit direct from the breaker panel, and have decent moisture control.

I had lots of issues cutting before I put the moisture control in. Just some things to think about.

Edit: also, I do always make sure I have a good, clean, shiny bare metal spot to ground to. 99% of the time my O/A torch is used to remove rusty nuts/bolts, not for cutting plate steel or the like.

Edit2: I should also note that when I say "rust", I don't mean scale. I mean surface rust. Plasma cutters don't like scaly rust. I usually bang it off with a hammer first and let 'er rip.

Certainly not doubting your statement. We'd all enjoy a video of your cutter doing two 1/2" plates at once!!!! :thumbsup: