I'm wondering if anybody has encountered this problem:
I have perfectly smooth edges on X-axis or Y-axis only runs, but on diagonals, the finish is quite rough.
There is a high frequency periodic (chatter) nature to the noise which I suppose I can attribute to the single flute ("o-flute") cutter,
but what is especially disturbing is the random and fairly deep gouges.
I'm running a Saturn 4x4 with CNCRP NEMA 34 PNP electronics (ESS) as well as the CNCRP PNP GMT spindle and driver.
I'm tempted to say the mechanical system is sound because X or Y only gives superior finish.
Attached are pictures of the smooth (X only) and rough (diagonal) runs.
Keep in mind that the "smooth" picture took me 10 minutes to capture. The lines present are exaggerated by getting the lighting just right.
It is almost a perfect finish and feels like glass to the touch.
The "rough" edge will make a "buzzing" sound if you run your fingernail across it. Very pronounced.
To get an idea of the scale, the Delrin plates shown are 1/2" thick.
Some additional info:
I have the belts tightened pretty good (with my index finger I can only manage to push in the side of the belt maybe 1/8"
I have the rack fairly tight as well (only requiring 3mils of backlash compensation in Mach3)
Material is Delrin
Bit is 1/4" Amana Spiral "o-flute"
Chip loading is low at 0.0015" to 0.0025" based on varying speeds/feeds I tried
Tried RPMs from 10k to 15k, but no faster than 25ipm (I'm looking for finish quality, not speed)
DOC 0.1" to 0.2"
Tried conventional and climb milling (conventional seemed a tad better)
Also tried cutting a pocket as well as only finishing an edge
Held my shop vac nozzle near the bit the entire time
I made a part using Fusion 360 CAM (based on mostly it's defaults) and just running diagonals via Mach3 MDI tab. No difference.
Running Mach3 on a Core i7 notebook with power saving modes turned off (via Ethernet of course to the ESS).
I have 4 unique aluminum brackets (all with very long diagonals) to deliver to a customer next Tuesday. I can just sand and polish for deliveries like this - but it is getting old.
Thanks for any ideas of what to try.