Hand to machine torch = loss of quality

[Circuit Pro]

Hey guys, I have an older PM45 and have been cutting with a hand torch on my Crossfire Pro for a year and a half or so. I primarily cut 1/4” HRPO steel and have had amazing edge quality with very minimal loose dross. The cut edges were so smooth it was almost like a glaze or something. Only issue was that occasionally the torch lead would hang the Z axis up.

Soooo, I got a smoking deal on a used but like new Duramax lock machine torch intended for an PM45XP. I got a pack of genuine electrodes and nozzles and tried it out today on an 1.5hr nest of 1/4 steel parts and was very disappointed. The edges are rough and there seems to be more dross than with the hand torch. The dross does still come off easily with knotted wire wheel. Also, these is some kind of super small and hard slag on the top which I have never seen before.

Book settings for the hand torch is 60IPM which yielded beautiful and smooth cuts. Setting for machine torch is 48IPM (don’t know why it would be slower?). I tried both speeds with the new torch but both cuts are kinda rough.

It’s not terrible, but I am spoiled from how smooth it has cut previously and I wasn’t expecting diminished quality from the machine torch.

I did pause and measure actual cut height and tweaked to exactly .060”

Anyone have any suggestions for tests I can do? Thanks!!

[Circuit Pro]

For air delivery I have an IR 7.5 HP 80gal with aftercooler, 2 refrigerated air dryers, then desiccant beads, then Motorgaurd.

Also, forgot to mention I’m getting more random bevel in some areas that before with the hand torch.

[adbuch]

Perhaps post some photos of your cuts so we can see the difference between your hand torch and machine torch cuts.
David

[cutnweld]

I did the same thing, had the same problems. Fixed it like this.Read through the thread if you have time it may help.
https://www.plasmaspider.com/viewtopic. ... 83#p226683

[weldguy]

That is strange, I wonder if it has something to do with air pressure. The 45xp will adjust the air internally where your 45 is manual. Is the whip length the same?

Can you cut a 2" square in .250 or thicker and post pics of it so we can see what kind of bevel your dealing with?

[adbuch]

I don't think simply adding an O-ring between the cap and body will necessarily remedy your problem. There are plenty of folks using the machine torch in stock form and achieving successful results. I would suggest posting photos of your cut results from the two different torches so we can actually see the results you are getting.

David

[rdj357]

It would also be good to know what consumables were used. Shielded with 220817 shield?

[cutnweld]

I don't think simply adding an O-ring between the cap and body will necessarily remedy your problem. There are plenty of folks using the machine torch in stock form and achieving successful results. I would suggest posting photos of your cut results from the two different torches so we can actually see the results you are getting.

David

Have you ever run a hand torch on a cnc table? Some of us have and know what the OP is talking about

[SeanP]

Did you take the torch apart to feed it through cable track or anything?

I did and and had grief for 2yrs or more! I'm not sure I had a slight leak on the torch body connection (where retaining cap screws onto torch) after running the torch lead through cable track.
Fought all sorts of problems, nozzles burning up, green tinge at end of cuts and part way through resulting in nozzle burn, had 2 replacement torch bodies with the last one resulting in burning out the small nut on the torch lead, I'm not sure that time it was my fault forgetting to nip up the connection.
So a new torch was installed end of last year and it's been great, better cuts, no nozzle burn and parts lasting far longer.

It doesn't take much of a leak to make a big difference, might not be the best way, but I now check that joint with soapy water in air test mode just to be sure.

[SegoMan DeSigns]

I'm with cutnweld on this one, disassemble, clean then reassemble the mechanical torch. My hand torch has less of a gap at the retaining cap / torch body than do both of my machine torches. Try his o-ring fix and see if it makes any difference. Here is some more O-Rings to look at..

https://www.plasmaspider.com/viewtopic. ... gs#p225011

[cutnweld]

It might not make a difference. I'm not saying it will. Just kind of strikes me funny that I basically am told that what is working for me is not working for me and will not work for anyone else. But hey that's fine, each to his own.

[Circuit Pro]

Hey guys, my sincerest apologies for not updating the thread. Work took a different direction for a bit but I’m back on it now. I added the O-ring referenced but didn’t notice a change. I will post pictures of edge quality between hand and Duramax torches although I have a hard time seeing the difference in the pictures. I can feel an obvious difference from touch. The picture from the hand torch cut was an inside cut and machine torch was outside. That is the reason for opposite cut direction in the pics.

The bevel is acceptable today. The edge from machine torch cuts are very rough compared to the hand torch. Backside dross is similar between the two so no complaints there. A slight bit of hard topside dross is present only on the machine torch cuts. Cut height is .060” verified, 48IPM on .250” HRPO steel. Hand torch was 60IPM. I have tried 60IPM with the machine torch but the edge quality gets even rougher.

[adbuch]

The edge quality you show in your photos would be perfectly acceptable to me.
David

[Circuit Pro]

Yea, I was afraid the pictures wouldn’t do it justice. I guess I’m spoiled with how smooth my old worn out, cracked hand torch cuts. The Duramax torch is said to have improved cut quality but that is not the case with mine.

[rdj357]

Get your settings from a PM45XP manual. I must have missed somewhere along the way that you were using an old 45 with a Duramax Torch. That setup works perfectly but you need to use the settings that go with the torch, not what's in your original manual. Get a copy from Hypertherm.com

[Circuit Pro]

Yessir, good thought! That is what I have done. I actually found an official HT chart for my exact combo ( OG PM45 with Duramax machine torch). Mr Colt linked it somewhere. The specs seem to match those of a 45xp (48 IPM for .250” steel) instead of 60IPM that the regular PM45 chart calls for.

[rdj357]

Great - yes that's what I'm seeing. 0.06" cut height, 0.15" pierce height, 48 IPM cut speed, 0.6 second pierce time/delay.

You're using the 220857 swirl ring, 220842 electrode, 220941 nozzle, and 220817 shield? Verified that you're maintaining the correct cut height while cutting?