Originally Posted by
Thermwood
We purchased a used 4x8 table with a powermax 45 several months ago and have been working on improving the system.
a few issues we have been trying to improve are ;
proma THC set up (we got it as close as it will ever be considering the inexpensive hardware)
angularity on thicker parts (played with cut height, feed speed, amperage, torch mount but still issues of angularity on 3/16 and 1/4 .... (we use "regular cut direction" for inside cuts & "reverse cut direction" for outside cuts
holes out of round (we have implemented some rules in sheet cam for smaller holes) inconsistent results ....
system is ;
generic 4x8 table 20/20 extrusions style with water tray, ball bearings relatively tight system considering the hardware ....
gecko drives
generic steppers - z axis - y axis - x master & x slave
mach3
sheetcam
proma thc
3 phase 100 gal compressor for entire shop, running our other CNCs no problem, air drier. dedicated 60 gal reserve tank between air feed and plasma.
hypertherm 45 with machine torch
a newer problem encountered recently ;
we had been cutting 1/4" test pieces relatively well ) except angularity, but decent cuts, minimal dross at about 60 ipm . test cuts were about 4"x4" or 2" dia holes, never long cuts ....
We tried to cut a series of 3" x 18" gussets and could not get a decent result ;
60 ipm - .8 s pierce - .15" pierce height - .06" cut height - Thc set to maintain approx .06" (also tried thc off same problems) - plasma set at 45 amps
new consumables - dry air )
cut starts well, proceeds through one long side then turns the corner and starts "gouging" for 3" then cuts through again...
the "gouging" sometimes happens on the long end, sometimes on the short end.
Cut always starts properly and cuts through for about 18 to 24" of cut before "gouging" ....
Checked ground, even ground steel plate clean, everything ok...
replaced consumables, lowered feed from 60 to 20 in 10 ipm increments, same problem ....
wondering if it may be a duty cycle issue, but our experience with duty cycle and this machine is actual loss of arc after 30 min of cutting ....
in this case we maintain arc but lose pierce and blow slag everywhere .... (ambient shop temp around 80F)
We also experience huge angularity when 1/4" cuts are successful, no real improvement with height changes. Angularity is parallel from opposite edges, direction of cut seems to affect minimally. questioning the torch mount (machine screw clamp), shimmed square as best as possible, no real improvement...
are we pushing the envelope a tad too far trying to cleanly cut 1/4" with this particular plasma model ?
Any input greatly appreciated ....
Pierre