Motor Tuning

Looking for some help with motor tuning.

Specs:
Nema 34 3.5 amp 1600oz/in motors
DM860A drivers / 2000step/rev
BL-MACH-V1.1 ST-V2 Breakout Board
16mm ball screws 5mm pitch - 10160 steps/unit (inch)
Mach3 Software - Version R3.043.062
Windows 7 Pro OS

When I open the motor tuning screen and tune the motors to 50ipm and velocity of 10 in/sec/sec. all the axis's move smooth and motors sound fine. After I save the settings and exit and move any axis the motors sound choppy and not at all smooth. I have tried adjusting everything ipm, velocity, kernel, nothing has helped. Any help or suggestions would be greatly appreciate. Thanks for your support.

So I have solved my problem! Apparently my PC was not enough to run the Mach 3 software.
Old PC!
Dell Optiplex 3Ghz cpu
1 G Ram
Win7PRO

New PC
HP 3Ghz
3 G Ram
Win7PRO

Now I have tuned my motors to 250ipm and it runs like a dream. Motors are smooth and quite.

Computer needed more rams....... Baaaaaa!
I'm using optiplex too, 4gb ram, 2gb pci-e gfx card, but using XP os instead. Win7 is too bloated.
I have the same breakout board type. I'm suspecting you were you using the on-board graphics chip?.

What CNC machine have you got?
I've tried those 1600oz motors before on a PM25 size mill and litterally threw them in the bin. Inductance was terrible.
Couldn't get above 1000mm/min (40ipm) without stalling or screaming (on 60V).
I learned the hard way as a newbie :rolleyes:

I changed to some 566oz (on 60V) and the machine flies.
Cam rapid at 3000mm+ (120ipm) and accel at well over 1000. I'm lmited by kernel. Going to upgrade to a UC300ETH.
5mm screws, drivers at 3000/rev, motor 600, kernel at 35000.
(I use mm)