Motor speed issues

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

Hi Rich!

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

CR.

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

Quote:

---

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.

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

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

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.

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.

codevark,

Did you see my post #6?

Mariss