Not cutting through after pierce powermax 65

[Dcollins8169]

Just purchased a 25 pack of fine cut nozzles and electrodes from hypertherm. I have not been cutting long, but everything has been going pretty well, and have been able to work through most problems. I was cutting a fairly intricate piece that I had designed and threw in a new electrode and nozzle for the cut. It did not go well! The following day I recut the piece but tried several test cuts before the attempt. I tried everything I could think of, even two more sets of new consumables from the new pack I had purchased. All the test cuts would not cut through the material. I forgot to mention 14 guage hr steel. I put an old electrode and nozzle that I had been using in and low and behold a beautiful cut that I am used to. Any ideas?

[acourtjester]

This has been talked about here before, If I remember correctly some seem to say they have like a breaking period with fine cut consumables.

[abmetal]

I wish someone had the answer for this problem. I've been trying to remedy this for a long time. I can put in a new Hypertherm electrode and fine cut nozzle, do a test cut, and get the same thing. After doing numerous test cuts at various speeds, heights, and whatever else I can think of, it'll finally settle down and cut like it's supposed to, and then it's fine for the life of the consumables. It's as if they have to have an initial warm up period. REALLY AGGRAVATING!

Allen

[WyoGreen]

I agree with acoutjester, there was a thread on this a while back. The way I remember it, the fine cuts are very finicky about the settings they run at. After they have been run a bit they settle down. Perhaps the following link will help you out.

ww.plasmaspider.com/viewtopic.php?f=4&t ... es#p144846

Steve

[Dcollins8169]

Thanks for the input! After I posted I browsed through earlier posts, which I should have done in the first place. I just haven't had this problem before.

[abmetal]

Yes, I've read past posts about the problem but I've never found a solution. We can start out with the settings we normally cut at, but until it just cuts for awhile, changing settings to whatever just doesn't help. After numerous setting changes and test cuts, we wind up back to the settings we normally cut at. It just seems that the nozzle and/or electrode has to warm up first.

Allen

[jimcolt]

I have posted the answer to this question on many forums, many times....regarding Finecut consumables not fully penetrating the material when cutting near the thicker end of their use , generally on 14, 12 and 10 gauge steel.

The problem is with a brand new electrode (no pit depth) the actual arc voltage at the recommended cut height is too low to get through various chemistry changes in the material. Higher than average levels of silicon, carbon and manganese in the steel make it harder to penetrate, and this can vary on a single sheet or from sheet to sheet. It is true that often a used electrode will cut better than a new one, why" Because the wear on an electrode creates a pit in the hafnium emitter, the arc starts in the pit and has to ravel a longer distance to the material being cut. A longer arc uses higher arc voltage.....and cutting power is calculated as Amps X Voltage = Watts.

With a new electrode (Finecut only) if you have this issue (not penetrating), increase the cut height from the book spec of .060" to around .075" to .080", this will adequately increase the arc voltage which will penetrate the material better. On height controls with a voltage setting that controls height....increase the arc voltage setting (probably 8 to 12 volts) in order to achieve a .075" to .080" cut height.

- Do not cut at a slower speed to solve the issue......unless you can live with more dross, a wider kerf and warpage (that is what low speed cutting does!). Stick with the book specs for speed, pierce height, pierce delay, amperage, leave the air flow in auto mode. Only change the cut height.

- Once a new electrode gets a hundred or so starts...feel free to go back to the book height....or leave it higher if desired.

Jim Colt Hypertherm

Just purchased a 25 pack of fine cut nozzles and electrodes from hypertherm. I have not been cutting long, but everything has been going pretty well, and have been able to work through most problems. I was cutting a fairly intricate piece that I had designed and threw in a new electrode and nozzle for the cut. It did not go well! The following day I recut the piece but tried several test cuts before the attempt. I tried everything I could think of, even two more sets of new consumables from the new pack I had purchased. All the test cuts would not cut through the material. I forgot to mention 14 guage hr steel. I put an old electrode and nozzle that I had been using in and low and behold a beautiful cut that I am used to. Any ideas?

[abmetal]

Jim,
I'd never tried going as high as .075 but I will try that. Usually I install a new nozzle when I'm going to do a lot of intricate cutting and a higher setting increases the cut width, so that was what I was wanting to prevent. But I guess I'll have to work around that.

Thanks.
Allen

[jimcolt]

Going from .06" height to .075" height may add about .001" to the kerf width....

Jim

[abmetal]

That's all? I've never gotten the calipers out but it sure looks like more...but I'll take your word for it. You're the master!

Thanks.
Allen

[treed67]

I know this is an old topic, but I'm suffering with the same issue with a Hypertherm PM45. On the straight (fast) cuts I get areas where it doesn't cut through and still getting quite a bit of dross. I'm using standard 45 amp consumables and have tried the 30 amp consumables as well. Cutting around 30 amps at 135 ipm on 16 gauge with a cut height of 0.06. I know I should be cutting faster, but the faster I go the worse it gets. I have actually dropped it down to around 100 ipm and solved the problem, but dross is too heavy. On the straight cuts I get areas where it doesn't cut through an still getting quite a bit of dross. Would raising my voltage/raising my cut height help? I have tried going lower but not higher.

[treed67]

I may have just answered my own question. I started looking at the charts in the manual and for the 45 amp machine torch consumables I should be running 225 ipm and 111 volts. I kept reducing my volts to get the torch closer to the material hoping to solve the problem. I have ran anywhere from 60 to 80 volts but never up to 111. I'll have to give that a shot. The part of amps x volts = wattage makes sense.

[acourtjester]

Remember that the voltage is a result of the cutting not a parameter, when you cut the voltage is to maintain the correct cut height.
Have you checked the "O" ring or the holes in the shield?

[treed67]

O-ring is good. The PM45 is almost brand new. I just bought it a few months back to replace a PM43. According to charts my voltage is way too low and my speed way to low. I’m using a PromaTHC but have my voltage set way low compared to book settings. I’m hoping that is my problem.

[acourtjester]

Are you attaching the return lead directly to the metal you are cutting, like a manual cutting operation?

[treed67]

Yes

[jimcolt]

Everyone is worried about setting the voltage. Arc voltage is simply the feedback mechanism that is used to maintain height. The plasma torch needs to be at the correct cut height (listed in the cut charts) in order to cut with the best quality. If the torch is too close to the material you will have collisions and will not fully penetrate the material....so increase the torch height (on many machines you set a higher voltage to increase the cut height) and you will get better results. Increasing the height (voltage) too high and you will cut with a wider kerf and more edge angularity.

Bottom line.....arc voltage and torch height are the same setting! Jim Colt Hypertherm

[tcaudle]

Find the best height by running a straight line test cut at the height you want with the THC disabled and watch the actual torch voltage (if you have a readout) Then that number becomes the one you need to use as the preset on that material and with a set of consumables. Not all THC readouts are accurate . It should be CLOSE to, but may not be exactly, the chart voltage. In a lotof CAM programs you can set the cut height (Intial Cut Height) and with the THC disengaged that arc gap should stay the same if the material is level and not warped