spectrum 375 and psi???

[dapozer]

I recently got a 375 and am starting to use it alot, however i am having issues with quality cuts and slag. The psi is set at millers req around 25-30 psi, however when i turn up the psi to around 50-70 it seams to work alot better. I have used a thermodyne and it set it psi at 75. Will uping the psi on the mikker hurt it? also what are your settings on this? I cut mild steel around 1/8 to 1/4.
Thanks
shawn

[enlpck]

I recently got a 375 and am starting to use it alot, however i am having issues with quality cuts and slag. The psi is set at millers req around 25-30 psi, however when i turn up the psi to around 50-70 it seams to work alot better. I have used a thermodyne and it set it psi at 75. Will uping the psi on the mikker hurt it? also what are your settings on this? I cut mild steel around 1/8 to 1/4.
Thanks
shawn

The pressure should be at about 60PSI. Where did you get 25 to 30 from?

Settings depend on several things. For a medium travel speed dragging the tip, I would be at about 20A for 1/8 and adjust speed for a clean cut. With the tip NOT in contact (about 1/16" gap or a tad less) on 1/8, the current could be a tiny bit lower for a given speed. If you want to move faster, raise the current. If too high for the speed, the cut quality is yucky. If too low, the cut will drop.

An excercise: Using a guide for a straight cut (clamp a strip to the piece being cut), on 1/8" material, set the current to about 20A, start the cut and run very slow. Speed up as you move along until the cut begins to drop out. Look at the cut and oyu will see the quality get good then go bad again. Change the current a little and do it again. Try this several times with higher and lower current. You will find a sweet spot where the cut is acceptable quality and the speed in comfortable.