[kognition]

Finally getting this turnkey mill ready for production machining. But i have been breaking endmills during cutting. I assumed i was doing something wrong in the TAP file generation. Frustrated, because i have orders i need to fill and product to make. I realized this afternoon that the spindle stagers intermittently at anything above 1,600 RPM! What can i do to fix this? I looked at the power supply in the box, but really nervous to touch anything. Any help would be appreciated!
Mike

[Runner4404spd]

do you have a 3 phase with vfd? it sounds like there is noise on the 10volt supply wires to the vfd that control the rpm its putting out. is there a schematic with teh machine? do you know what the speed control board looks like?

[kognition]

It's a PMDX motherboard with the spindle driver card installed on it. And i did notice that the wires from the spindle driver card are not shielded. I temporarily fixed the problem by lowering my feed rate to 70%. And that stopped the voltage drop. But its puzzling.

[Runner4404spd]

i'm not familiar with the pmdx board but usually they can some kind of volated adjustment via a pot to tune in your 0-10v for your vfd input. also check make sure the wires are not loose and check all the screw terminals to make sure they are tight. also make sure your power supply wires to the pmdx board are tight and make sure there isn't too much load on the power supply so that its dropping volatge. other than that i would call pmdx and see what they can help you with over the phone.

[philr07]

I took delivery on a turnkey IHCNC in October. I've noticed what seems to be a split second drop, then recovery of power to the spindle, at my usual running speeds. It was usually within a few of minutes of starting the spindle. I run between 960 and 1800. It's never caused an end mill (1/4") to break. I went thru the connections with a screwdriver to ensure all were snug, and did not encounter any obviously loose connections. The problem seems to have subsided over time, but still occurs on occasion.
I also note when I run a few hours of production at 1800 rpm, the oil gets very warm as well as the tools and gearbox. The tools get warm enough where it's uncomfortable, but still possible to change with the bare hand. My shop temp runs about 80F. I don't think my gear head IHCNC would run a continuous day's production at speeds above 1600 RPM, at least not without rest.

[saabman]

Spindle speed can also drop if you are doing things in the Mach3 GUI. The foreground activity seems to disrupts the puleses to the spindle controller my system. No problems when running code however.