Plasma cutting - what am I doing wrong?

[plastikosmd]

similar to above, to what was noted above.I have found air supply is also critical. My air is regulated for whatever the machine requires, I think it is 80psi? I have an 80 gallon compressor and even on a 12" long cut I will trip the compressor. I cannot imagine running my plasma without constant dry air at the right psi. I don't prep anything rust, scale whatever, I only prep where my ground will be connected. I also have no trouble with 1" cut, I think my machine is rated 1.25 sever and 3/4 or so pierce(100% duty cycle). I'm not sure of the rating for the hypertherm45

 

[dragoneggs]

I don't think air is the problem. I have a separator at the compressor and there is one built into the 45XP. I'm not dipping below 90psi.

Thinking voltage. Here is the cut...

 

[ovrszd]

Will be interesting to see/hear opinions. Appears your speed is good. The cut is very rough though. Assuming you were using a guide?

I'm not qualified enough to discuss the slag. I actually don't worry about that too much.

Are you still using the same tip and electrode that you cut the blade with?

 

[sdef]

OVRSZD: The tip has a circular 1" diameter "cage" around it that sets the correct working height above the material. I typically use a piece(s) of angle held in place with magnets: Bessey Magnetic Welding Square, 3-3/4InLx3/4InW WMS-5 | Zoro.com

I understand that wood is doable as a guide also. But it would need a clamp to be held in place and I have not had a need to try this method yet.

 

[ovrszd]

OVRSZD: The tip has a circular 1" diameter "cage" around it that sets the correct working height above the material. I typically use a piece(s) of angle held in place with magnets: Bessey Magnetic Welding Square, 3-3/4InLx3/4InW WMS-5 | Zoro.com

I understand that wood is doable as a guide also. But it would need a clamp to be held in place and I have not had a need to try this method yet.

Thanks for the reply. I've considered trying elevated tips but just couldn't figure out how to guide. Is your "cage" an item purchased and added to the gun?

 

[yomax4]

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.

 

[sdef]

Thanks for the reply. I've considered trying elevated tips but just couldn't figure out how to guide. Is your "cage" an item purchased and added to the gun?

Mine came standard with the cage. These are replacements I stocked up on: C1394 Spacer Spring Fit Cebora P7 CP-7 Trafimet CB7 S45 CV 743.149 5PK | eBay

Contact tips are optional, which I have yet to purchase. I have no photos of it in actual use. Attached are a few pics of a weigh box just completed with lots of help from the plasma. The 3PH pallet mover tines/support arms were cut to length with the plasma and then welded parallel with the pieces left to allow more support for the weight box. Also cut the holes for the 2" receiver, along with cutting off a bale spear type contraption. All of these cuts would have been much more difficult with any other tool. Angle iron guides used for all cuts except the spear which was free hand.

Box weighs 1240# measured and has internal storage space or enough room to add more weight if necessary.

 

[Big Barn]

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.

 

[Jeepnford]

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.

 

[Big Barn]

Thanks for the reply. I've considered trying elevated tips but just couldn't figure out how to guide. Is your "cage" an item purchased and added to the gun?

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.



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.



Terry

 

[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.