Hi,

I have a powermax 45 on a cnc table- running Mach3 software/Bladerunner AIO with DTHC. I dry my air with a submicronic paper filter and then a fairly large dessicant dryer.


Yesterday I was cutting a large job in 3/8" plate, and towards the end cut quality completely went away. Long story short, Now I cant get it to cut cleanly again. I've changed my tip/electrode more than once, and "cleaned" the shield cap- I have some on order, but not very confident the shieldcap is causing the problem anyway. I also changed the paper filter- the dessicant is in good shape.

Watching during a cut, after the torch has been on a short bit, the voltage varies alot up and down, causing the DTHC to pulse and create a crappy, saw like cut.

What could be causing my tip voltage to vary? Can this still be a moisture issue?


*EDIT*

I had some time to try a few things out, it looks like the problem is related to the THC/ tip voltage situation. The cuts start relatively clean, and seem to get worse the longer the torch burns. Watching the Mach3 screen, the tip voltage starts out ok- hanging close to its setpoint, but then starts to climb and dive the longer the torch burns.


1. Ground issue? I tried clamping the torch ground directly to the workpiece with no noticable change. I thought possibly moving and banging the heavy 3/8" sheets around on the table cound have changed something. My table is not directly connected to an earth ground/rod.

2. PC related? my PC's are not in the best condition. I actually had a mouse in this one, hanging out on top of the video card- caused it to short out apparently. After replacing the card the PC booted fine and seems to work normal.


Thanks for any and all suggestions

Ben W