Plasma cutting - what am I doing wrong?

[MossRoad]

On the subject of running out of air... a way to lessen the frequency of the compressor having to start is to increase the air storage capacity. Many of us have these portable air tanks sitting around. (like this one from Sears for $25). You can tee one or two or three or four into the lines with quick connects and increase your air storage capacity. Its not much as these are only 5 gallon tanks, but sometimes just a little is better than nothing... and it's a handy way to keep the portable tank charged up, too.



Sears.com

 

[dragoneggs]

Remember that there are 2 types of Dross (slag) Low speed from too slow of travel speed and High Speed from too fast. Low speed dross is easy to remove and High speed dross is difficult to remove. Your pics are what normal hand held cutting looks like whan not using a stand off or guide. Most times the cuts like these are fine, Knock off the dross, Touch with the grinder and weld. Even with a flat plate and a straight edge you will get some dross because you will have a hard time keeping the perfect speed. The little ripples in your cut are simply motion. No Worries, Cuts look normal.

The dross did NOT come off easy. Had to take a grinding wheel to it and it was still a bit of work. The cut looks crappy compared to other 1/2in cuts I have seen. Also realize it took a second pass to sever this. I did use a piece of metal that I bent and clamped into place. Similar to how I cut the 1/4in blade shown here.

Mark.

From the info you give I would guess that your air quality is not an issue and you are not getting the amps you need due to your restrictive extension cord.

Here's a pic of 1/2" plate cut with my Miller 625 Extreme (and
and from what I can gather a LESSER capacity machine than yours).

Wide blade chisel pictured makes short work of dross removal. View attachment 504523

That's is more what I was expecting. The whole reason I decided to go with the 45XP vs. the 30XP or Miller equivalent.

I think when you are able to wire a 50 amp receptacle you'll go a long way toward solving your problem. My 45XP cuts on 1/2 look a lot like Big Barns and I have to use a guide.

Yes, I am pretty sure it is my redneck 220v wiring to my shop. I am planning to extend my garage to have a bigger dedicated shop so I have been waiting to run wire from my main panel until I can do it right. If I ran it now, the sub panel would not be where I want it later and my run would be longer and maybe in the way of my foundation work.

 

[dragoneggs]

On the subject of running out of air... a way to lessen the frequency of the compressor having to start is to increase the air storage capacity. Many of us have these portable air tanks sitting around. (like this one from Sears for $25). You can tee one or two or three or four into the lines with quick connects and increase your air storage capacity. Its not much as these are only 5 gallon tanks, but sometimes just a little is better than nothing... and it's a handy way to keep the portable tank charged up, too.

View attachment 504537

Sears.com

I have a 60gal and I think I am covered once I solve my wiring issue. For me, it is the constant plugging/unplugging of 220v machines during a stint in the shop. Driving me crazy ullinghair:

 

[MossRoad]

I have a 60gal and I think I am covered once I solve my wiring issue. For me, it is the constant plugging/unplugging of 220v machines during a stint in the shop. Driving me crazy ullinghair:

Yep. Rewire that puppy. :thumbsup:

 

[TMGT]

One thing I didn't see mentioned much was gun angle, it doesn't take much to increase the effective thickness of the material a lot. I find this especially true on curved surfaced where your hand gets lazy and doesn't adjust quickly to the angle change.
I've had this problem before with my 45 and finally figured it out, it was most notable on 3/8 and up.

The electrical has already been stated, I would add a small filter, like what's used on automotive paint guns, right before the inlet on the machine. I use them and noticed an improvement in the consumables longevity. That is in addition to a water separator at the machine inlet and one at the compressor outlet.

 

[TemporaryKubotaOwnerMark]

If your are not tripping the circuit breaker, I don't believe the extension cord is causing the problem. .

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.

Thank you, Mr. Foster, for correcting that error.


You can easily trash an electric motor from low voltage without ever tripping the breaker. As my neighbor who went through 4 sump pumps in his hard in as many years. Inadequate wring by the previous owner, who also went through sump pumps and never figured it out. :confused2:

 

[shaeff]

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

Next time I'm at the garage I'll find some 1/2" plate and give it another whirl.

 

[ovrszd]

Mark.

From the info you give I would guess that your air quality is not an issue and you are not getting the amps you need due to your restrictive extension cord.

Here's a pic of 1/2" plate cut with my Miller 625 Extreme (and
and from what I can gather a LESSER capacity machine than yours).

Wide blade chisel pictured makes short work of dross removal. View attachment 504523

Nice cut Terry. Perfect speed, smooth tip control, sharp tip/electrode.

My machine is same model. I had the earlier, large bulky 625 before. I like this smaller model much better. Comes with it's own carrying case. Easy to be mobile.

 

[ovrszd]

Richard. My first Miller Spectrum plasma I purchased almost 20 years ago didn't have elevated drag tips.

I made this straightedge guide to maintain correct cutting height for material over 3/16". I JB welded 3 aluminum vice jaw protectors to a length of aluminum angle iron (at appropriate height) for the plasma's retaining cup to slide on.

View attachment 504535

I also have a short magnetic guide for smaller cuts. The edge is elevated at the correct height for NON standoff tips. It's branded "Hypertherm" but I'm quite certain it's made by Flange Wizard.

View attachment 504536

Terry

Good stuff Terry. Thanks for the ideas!!!

Do you use a Drag Tip now??

 

[ovrszd]

Next time I'm at the garage I'll find some 1/2" plate and give it another whirl.

Thanks!!! Next time I'm cutting I'll try to shoot video as well. The ole "picture is worth a thousand words" philosophy.