Messages

11

General Mach Discussion / Re: Brushless DC Servo Spindle Speed Control w/ Smooth Stepper and Leadshine

« on: December 07, 2011, 10:27:18 AM »

Thanks a lot for the feedback guys.

Swapping the step and direction wires or signals gives no motion.

I definitely the frequency to 256k in the SS config...this high frequency capability is the only reason i bought a SS.

The acceleration doesn't seem to effect the motor right now as i'm just running it on the bench with no inertial mass or load...but i've tried a range of values.

One other thing is that I'm sending these signals through Port 1 and into a Gecko 540 and passing the step and direction signals through the two OUTPUT channels. I believe these channels simply take a pin from the DB25 and pass through the 540. You wouldn't suspect that this is getting messed up passing through the 540 would you?

12

General Mach Discussion / Re: Brushless DC Servo Spindle Speed Control w/ Smooth Stepper and Leadshine

« on: December 07, 2011, 12:41:02 AM »

If I switch it in mach then i get no motion. If switch it in the motor driver then I get reversed motion.

13

General Mach Discussion / Re: Brushless DC Servo Spindle Speed Control w/ Smooth Stepper and Leadshine

« on: December 06, 2011, 11:08:11 PM »

thanks for the suggestion Ray.

I just tried running the motor as the Y axis with these Motor tuning Settings:

Steps/unit: 4000
Velocity: 3000

the motor will only turn when i run at 3% or 6% of the full velocity (so 90 rpm or 180 rpm respectively). The crazy thing is that at 90 RPM it runs CCW and at 180 RPM it runs CW? WTF?

14

General Mach Discussion / Brushless DC Servo Spindle Speed Control w/ Smooth Stepper and Leadshine

« on: December 06, 2011, 06:27:18 PM »

I'm trying to use a brushless DC Servo motor as my spindle motor and control it with step and direction pulses from Mach3 to a SmoothStepper and Leadshine Driver. After a couple weeks of struggling I could really use some help. So far i can only get the motor to spin at about 1.5 rev/second max no matter what the settings.

My set up:
Windows XP
Mach3 R3.043.022 (lockdown)
SmoothStepper USB Driver 2.08.14
Plug In: SmoothStepper_v17efb
Motor Driver: Leadshine ACS606
Motor: Leadshine BLM57180 (180W brushless DC Servo Motor)
1000 encoder counts per rev
max motor vel: 3000 rpm

Mach/SS settings:
port and pin: Spindle: Step/direction
Motor Tuning: Spindle:
Step/unit: 4000   (assuming this is step pulse per rev?)
Vel: 3000            (assuming this is RPM of the motor and not the spindle?)
Accel: 500
pulley: 25000 max (I'll explain below)

The bottom line is that with these settings the motor will only move within a narrow band of commanded speeds. At S-500 it will turn at about 1 rev/second, at S-875 it will turn at about 1.5 rev/second. Logically i want to set the pulley to 3000 max which should give me a 1:1 motor to spindle ratio which would be nice for development, but within this band the motor will only move slightly at around S-100. Above or below these speeds it just doesn't turn.

Originally (before I got the SS) i though this limitation was because of the high number of pulses needed and the limitations of Mach and the Parallel port. I have the spindle port on the SS set to allow 256k Hz to the spindle which would be sufficient to run the motor at 3000rpm.

I've also set the pulse width in the SS config to 1us as suggested by the Leadshine controller documentation.

Using the Leadshine controller tuning software i can get the motor to spin at 3000 rpm so i don't think its a wiring issue.

The last thing i can think of is that the leadshine controller doc suggests that the direction pulse must lead the step pulse by 5us min. I've tried every combination of step and Dir pulse settings in the motor tuning and it has no effect. Is there a way to control how much the direction pulse will lead the step pulse?

any help would be greatly appreciated.

Kyle