Originally Posted by
binfordw
Hi,
Past few days I've noticed some odd cut behaviour from my PM 65. I have had little to zero extra time to look further into the issue, but would like thoughts on the most possible issues.
Issue is heavy dross on bottom of parts, and light "dross?" on top of cut, but it seems to come and go somewhat. Looking at the cut from the side, it looks like the torch itself is weak- the cut lines curve alot- much like a severed cut in thick metal would look.
These cuts are in 3/16" mild steel. I use 45 amp and 70 ipm for these cuts, have for a long time with good results.
This seems to have started after I cleaned the table out, ie, removed all slats, drained table, scooped debris out, etc. I first thought perhaps it was a poor ground clamp connection, but putting the clamp directly on the sheet made no difference. (I thought this, because while running a long job after cleaning table, I noticed at the end of a slat where it fits into table, a small glowing orange spot emitting smoke while torch cut. As the torch got farther away from that slat, it lessened. I have never seen that before, just assumed it was a poor ground connection for that slat.)
Or- the usual culprit of moisture in air. I had run the machine alot before issue occured. I do have a pretty large dessicant filter bowl setup 2 feet from the plasma however. Changing to new nozzle/electrode gained no improvement. Not even on the very first small cut. I dont want to rule out moisture yet, as its generally the cause of most problems it seems, but from what I've seen so far I dont think its too likely.
The Swirl rings never seem to go bad- but I have never changed mine either, I dont have any idea of what a "bad/worn" swirl ring might do to cut quality- Is this a possible cause?
Only other thing that comes to mind is air pressure. The Plasma is happy with the inlet pressure, but perhaps some debris has blocked something partially in the torch itself?
Thanks for any thoughts