Not sure if a sheetcam problem or not

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regpye
Posts: 57
Joined: Sat Nov 09, 2019 1:12 am
Location: South Australia

Not sure if a sheetcam problem or not

Post by regpye »

This one has got me beat so far.
Just recently I moved to another computer and since then the plasma cuts have been pretty poor.
As far as I know, I didn't change anything in sheetcam. I copied my tools and settings and used them on the next computer (an old one that has a printer port)
I have had to reduce the travel speed in order to get a better cut, but the flame still seems to wander a bit (sometimes has a green tinge as well). The dross is a bit heavy too, probably due to reducing the speed. I mainly cut 3mm (1/8") mild sheet.
I have changed both the nozzle and the electrode, checked the air flow, and have a drier in the airflow line, purged the compressor tank and line filters.
I also noticed that there is a high pitched sound coming from the cut itself when starting, to me it sounds like the air is making a whistle sound from the cut it has just made. I never heard this before, it is a recent development.
The plasma cutter is a Viper 30, only a low amperage machine, no bells and whistles (until now), suppose to be for handheld cutting, but has worked flawlessly until just recently..
Any suggestions guys? I would like to purchase a better cutter, but that is out of the question at this time. I would also like to add a THC as well, ditto.
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Les Newell
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Joined: Thu May 11, 2006 8:12 pm

Re: Not sure if a sheetcam problem or not

Post by Les Newell »

Heavy dross on the underside sounds like you are cutting too slow. It could also be that you are cutting too high. The green tinge is the arc burning the copper nozzle. This could again be due to cutting too high or it could be some other factor such as air pressure causing the arc to become unstable.
regpye
Posts: 57
Joined: Sat Nov 09, 2019 1:12 am
Location: South Australia

Re: Not sure if a sheetcam problem or not

Post by regpye »

Les Newell wrote: Fri Apr 10, 2020 1:01 pm Heavy dross on the underside sounds like you are cutting too slow. It could also be that you are cutting too high. The green tinge is the arc burning the copper nozzle. This could again be due to cutting too high or it could be some other factor such as air pressure causing the arc to become unstable.
Thanks for that info Les. My pierce height is set at 3mm and I am cutting at 1.5mm. I never had this problem before at those settings.
If I increase the speed much more I get blowback and uncut parts (throw away job) I am now cutting very slowly at only 450mm/min. At that speed the cut is better, the sparks go in a downward direction, if I increase the speed much more the sparks are directed in a backwards direction to the travel. Maybe the plasma cutter has lost power? When I first used it I was able to cut cleanly and at speeds more that triple the speed I am using now. I have the machine set at flat out, 30 amps.
I have tried changing the air pressure also and found that if too high I get poor results, if too low the machine wont cut at all. The manual says to use 5-6 bar (70-87 psi) and I am in that range.
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djreiswig
Posts: 471
Joined: Sat Feb 20, 2016 4:47 am
Location: SE Nebraska

Re: Not sure if a sheetcam problem or not

Post by djreiswig »

Is your work clamp attached directly to the material? Maybe your cable has a bad connection on one of the ends not letting full amperage through.
regpye
Posts: 57
Joined: Sat Nov 09, 2019 1:12 am
Location: South Australia

Re: Not sure if a sheetcam problem or not

Post by regpye »

djreiswig wrote: Sat Apr 11, 2020 12:56 am Is your work clamp attached directly to the material? Maybe your cable has a bad connection on one of the ends not letting full amperage through.
I always attached directly to the work piece and I have checked the cable and it is good. This machine doesn't have a removable earth cable, so maybe there is a loose connection inside the machine, I will check that and see if that is the problem.
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