Motor speed issues

[rich_cree]

Hi everyone. I'm struggling a bit to get my motors running right. I'm running Mach 3, with a Gecko 540 and Kelling 48V power supply & motors on a Taig mill.

I managed to calibrate everything fine, so each axis moves what it says it should when I ask it too. I tried some of the wizards in Mach 3 and they all seemed to work ok as long as the feed rate was high.

My problems come when I tried to cut my first proper part. I generated the g code in meshcam and I was really conservative with the feed rates (didn't want to do any damage). It seems my motors just don't run at all if the feedrate is too low. By low I am talking about 4ipm (100mm/min). Surely I should be able to run the motors this slow?

The part I test cut looks a mess. It's all of about the right dimensions but the circular pockets are all out of round, and the external walls are a bit chewed up where I'm guessing the mill has lost/gained steps.

Any ideas why my motors stall at low speeds? Is this normal??? When I jog, if I set the reduced jog % too low then my motors don't move, but if I hold the shift key down they move fine.

Thanks for any help guys!

Rich

[Crevice Reamer]

Hi Rich!

What Keling motors are you using? Have you tried adjusting the "trim" on the G540?

CR.

[rich_cree]

I've got this package:

G540 4 axis package (one G540 + Three KL23H276-28-4B( 1/4” Dual
shaft with a flat) 270 oz-in + one KL-350-48 48V/7.3A 115V /230V
power supply).

Trim, no I haven't tried that. What does it adjust?

Thanks

[Crevice Reamer]

Originally Posted by rich_cree I've got this package: G540 4 axis package (one G540 + Three KL23H276-28-4B( 1/4” Dual shaft with a flat) 270 oz-in + one KL-350-48 48V/7.3A 115V /230V power supply). Trim, no I haven't tried that. What does it adjust? Thanks

You may not HAVE to adjust this. First, make sure your step/direction pulse width is set to 2 in Mach3.

ADJUST: This trimpot adjusts the motor for the smoothest possible low-speed operation. Set the motor speed to
about 1/2 revolution per second and then turn the trimpot until a distinct null is noted in the motor’s vibration. This
will result in the most even microstep placement for a given motor and power supply voltage. The default setting for
this trimpot is at ½ -turn and the setting for your motor will be within +/- ¼-turn of the default setting.

CR.

[fretsman]

Rich, I asked you a question about your issues here in your other thread but I see you haven't replied.

Please have a look and see if that may be your problem:

http://cnczone.com/forums/showthread.php?t=73778

Dave

[Mariss Freimanis]

Mach3 "ports and pins": Set step "active high".
Mach3 "motor tuning": Set step pulse width to "2" microseconds.
In BIOS: Set parallel port to "EPP".

Mariss

[codevark]

Does the trim pot turn all the way around without wrecking? I was trimming my motors with the g540 and now I can't get one of my motors to spin when the speed is low like .5 rpm. I don't know where the original spot was on the pot now. I know so stupid of me.

[Crevice Reamer]

ADJUST: This trimpot adjusts the motor for the smoothest possible low-speed operation. Set the motor speed to
about 1/2 revolution per second and then turn the trimpot until a distinct null is noted in the motor’s vibration. This
will result in the most even microstep placement for a given motor and power supply voltage. The default setting for
this trimpot is at ½ -turn and the setting for your motor will be within +/- ¼-turn of the default setting.

CR.

[Mariss Freimanis]

codevark,

Did you see my post #6?

Mariss