Looking for ideas:
I cut a lot 3/16" and some 11ga steel. Before a week ago or so, I had my settings dialed in with a Hypertherm powermax. Very little to no dross on the edges - A little dross with small holes. Basically book settings. Now, using the same settings, new nozzle, new electrode, clean air filters and drained air compressor, I'm getting increased dross - I think it is slow speed dross (easy to knock off if tapping the edge), but certainly doesn't flick off with a finger nail so not sure. Edge angularity may be slightly increased at times, but not much and not consistently like the increased dross.
Edit: To correct myself, the electrode is not brand new, but it's appearance shows little wear compared to Hypertherm's consumable troubleshooting chart. But still, not new.
The only thing that I can think of is room air temperature is now a little higher than it was this Winter, but I've never heard of any setting reference to room temperature. Now that I write this, I didn't think to replace the swirl ring nor add silicone to the o-ring although they don't appear to be plugged/worn or dry o-ring. Retaining cap appears to seal good when installing on torch body. Shield looks good and none of it's holes are plugged. I don't notice air going where it isn't supposed to go. Using a water table which is at it's same level - Maybe ~1/2" below material.
Any ideas, please?
TNX
Paul
Increased Dross Recently
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jimcolt
- 5 Star Elite Contributing Member
- Posts: 3087
- Joined: Mon Jul 20, 2009 11:18 pm
- Location: North Carolina
Re: Increased Dross Recently
Dross is caused by:
- Cutting too slow
-Cutting with too much power
-Cutting with the torch to work distance too high
-Cutting at the incorrect cut pressure
-Damaged consumables (swirl ring, shield and retaining cap will wear out eventually)
-Leak or restriction in air system
-Different plate or sheet chemistry.
If you are sure the height is correct (the physical height, the arc voltage is just a number) and the air flow is not restricted......you have tried new nozzle, electrode, swirl ring, shield and retaining cap (I would swap them out one at a time), and you think the dross looks like low speed dross (relatively easy to remove by chipping).....then increase the speed a bit at a time (maybe 5 ipm) and check the dross. Faster almost always gets rid of low speed dross, sometimes a lot faster. Different sheets of steel can have different silicone and carbon content, both of which can dramatically affect the Dross Free Zone (speed range between low and high speed dross). In some cases the DFZ is very narrow or even non existent. Temperature of the plate certainly can make a difference....but only if you are running pretty close to the edge of the dross free zone....usually it can be compensated for with higher cut speed.
Jim Colt Hypertherm
- Cutting too slow
-Cutting with too much power
-Cutting with the torch to work distance too high
-Cutting at the incorrect cut pressure
-Damaged consumables (swirl ring, shield and retaining cap will wear out eventually)
-Leak or restriction in air system
-Different plate or sheet chemistry.
If you are sure the height is correct (the physical height, the arc voltage is just a number) and the air flow is not restricted......you have tried new nozzle, electrode, swirl ring, shield and retaining cap (I would swap them out one at a time), and you think the dross looks like low speed dross (relatively easy to remove by chipping).....then increase the speed a bit at a time (maybe 5 ipm) and check the dross. Faster almost always gets rid of low speed dross, sometimes a lot faster. Different sheets of steel can have different silicone and carbon content, both of which can dramatically affect the Dross Free Zone (speed range between low and high speed dross). In some cases the DFZ is very narrow or even non existent. Temperature of the plate certainly can make a difference....but only if you are running pretty close to the edge of the dross free zone....usually it can be compensated for with higher cut speed.
Jim Colt Hypertherm
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urbnsr
- 3 Star Member
- Posts: 329
- Joined: Wed Dec 26, 2012 6:13 am
Re: Increased Dross Recently
Thanks Jim. Again...
In this case, I am going to assume the first two on this list are not part of the problem since I had great result before using these settings before. I also checked that I have my set regulated 110PSI at the back of the cutter. I will check the PSI while running. I periodically check the cutting height, but will double check it. I will replace consumables individually to see if anything shows up there. The material is coming from my same supplier, but probably next to impossible to confirm the supply chain unless there was a definite change somewhere along it's route.
Thank you...
Paul
In this case, I am going to assume the first two on this list are not part of the problem since I had great result before using these settings before. I also checked that I have my set regulated 110PSI at the back of the cutter. I will check the PSI while running. I periodically check the cutting height, but will double check it. I will replace consumables individually to see if anything shows up there. The material is coming from my same supplier, but probably next to impossible to confirm the supply chain unless there was a definite change somewhere along it's route.
Thank you...
Paul
