Hafnium pit off center normal?

[impsux]

I have a Hypertherm PM45xp and I was cutting well with finecuts at bookspecs at the start of my adventure but now the good times are gone. I began having issues a couple months ago that cutting higher (.07-.08) seemed to fix. I then started getting pretty consistent bevel on the same sides of cut that seem to be chewing through nozzles. I started throwing money at it with a motor guard and a refrigerated dryer.

IMG_20200822_110932683_2.jpg (27.72 KiB) Viewed 722 times

I have 4 electrodes that look like this. I'd replace a part and cut about 20 inches and check the electrode, replace another part with a new electrode and go again. I ended up with all new O-ring, swirl ring, retaining cap, shield, electrode and nozzle. The last electrode still starts off-center even with all new consumables. I don't have a gauge at the back of my plasma but I have ran the pressure test from top to the bottom of a compressor cycle and reading on the plasma unit never dropped below 65 psi (I believe 66 psi is its default setting). Do I need a new torch?

[adbuch]

Could you please provide a photo that is more in focus? I use a 45xp and am familiar with the consumables, but it is hard for me to see (from your photo) exactly what is going on.
Thanks,
David

[impsux]

Hope its not too dark.

[adbuch]

At first I thought you took a photo of the inside of your nozzle, but now I see this is probably showing the end of your electrode. It looks like a typical worn electrode except for the swirl mark. Are we looking thru a magnifier, or? I run my 45xp at 100 psi at the machine while it is cutting. Your problem may be related to low air pressure. Here is some information from Jim Colt of Hypertherm about air pressure for the 45. The 45xp manual indicates that 85 psi @ 400 scfh is the minimum air supply requirement.
David


viewtopic.php?t=9816

[impsux]

The picture is a magnified electrode with 1 pierce on it. Put a gauge at the back of the cutter and it doesn't drop below 95 psi during a refrigerator purge and running the pressure test on the cutter.

[adbuch]

OK - you mentioned 65 psi in your original post. I would suggest joining the PlasmaCAM CNC Tips, Talk, Trade Facebook forum and posting your photos and question there. Jim Colt of Hypertherm is active on that forum and can probably help you. You do not have to own a Plasmacam to join.
David

https://www.facebook.com/groups/PlasmaCAM.Tips/about

[djreiswig]

Found this on the Hypertherm site.
https://www.hypertherm.com/en-US/learn/ ... en-plasma/

[adbuch]

https://www.hypertherm.com/en-US/learn/ ... electrode/

[weldguy]

That swirling stain on your consumables indicates contamination in your air supply being burned up as it enters the plasma arc with the swirling air. Possibly compressor oil or could just be moisture.

I read that you installed a motor guard filter and refrigerated dryer which is great however prior to having those installed you have already contaminated your air lines and the 25' Hypertherm torch lead and I am not sure for how long. It will take many hours of operation with clean dry air to get that contamination cleared out of your lines and torch lead.

If your air lines or torch lead have low hanging loops where moisture could sit hold those up high and purge air through the torch, this may help speed things up. If your air lines are old and gross try replace them with new 3/8 ID lines.

Stick with it but to me it looks like contaminated air.

[adbuch]

That swirling stain on your consumables indicates contamination in your air supply being burned up as it enters the plasma arc with the swirling air. Possibly compressor oil or could just be moisture.

If the plasma torch line is contaminated with compressor oil, then perhaps it could be flushed out with isopropyl alcohol. If the compressor is fairly new, then I would be surprised of compressor oil contamination is the issue.
David