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Topic: Stepper Motor Vibration Velmex BiSlide (Read 305 times) previous topic - next topic

tyscof

Hey everyone I work doing experiments at a university and we have a setup that uses a Velmex Bi-Slide; this came with a Vexta unipolar motor (PK266-03A-P1) and Velmex driver. I recently attatched a force sensor and I noticed that there were large spikes whenever the traverse started and stopped. I checked the motor driver and it only did 1/2 steps so I figured it must be something to do with impulsive loads since the weight of my system is ~5lb. To test this I hooked up the motor in a bipolar configuration and used a  SainSmart Driver This was with accel stepper codes:
Code: [Select]
#include <AccelStepper.h>
AccelStepper stepper(AccelStepper::DRIVER, 9, 8);
//AccelStepper stepper; // Defaults to AccelStepper::FULL4WIRE (4 pins) on 2, 3, 4, 5

void setup()

   stepper.setMaxSpeed(1000);
   stepper.setSpeed(500);
}

void loop()

   stepper.runSpeed();
}

I have set it to 1/16 stepping and found that this reduced that initial peak by a lot. But there is alot of vibration in the leadscrew. With the previous Velmex driver you could not feel any vibration with your hand on the traverse but now with this sainsmart driver you can noticeably tell that there is a significant vibration. So although this does help the initial peak in that force sensor the vibration will create a different problem for me. So my question: Is there a way to significantly reduce this vibration? Am I doing something wrong that is leading to this vibration? Why does the Velmex drive not have this vibration?

Paul_KD7HB

Lead screws must have good thrust bearings on either end. Is this the vibration you are sensing or is it the leadscrew rotation that is vibrating?

Paul

Daenerys

If you posted a video that would be most helpful.


I would try reducing the current to the motor.
What current are you running it at?

tyscof

Lead screws must have good thrust bearings on either end. Is this the vibration you are sensing or is it the leadscrew rotation that is vibrating?
The stepper is vibrating which is causing the leadscrew to vibrate. When ran by the Velmex driver there is no vibration. Any ideas?

outsider

Did you try various current, torque and decay settings?

tyscof

Did you try various current, torque and decay settings?
I haven't tried various decay settings, just have it set to no decay. I wasn't sure what that even did so I figured I would leave it on full blast.

My motor is rated at 2.6 amps and my driver is current limiting to 3 amps, I have it set to the maximum setting for amperage. When the motor is moving the variable power supply is only drawing ~1.5 amps at 12v. I also tried limiting this to the 1 amp setting, this made the noise/vibration smaller but again I think that was just because there was less torque and energy going into the motor not that it "fixed" the problem.

Not sure if maybe the problem is with the arduino? I should be able to go low speeds with the arduino and need something faster for quicker movement right?

Again for some reason using this arduino driver seems to make the motor and/or lead screw vibrate and when using the generic driver from the manufacture there seems to be no vibrations.

outsider

#6
Dec 05, 2017, 05:11 am Last Edit: Dec 05, 2017, 05:15 am by outsider
How did you set the accel rate in AccelStepper?
Can you post a link to the Velmex driver?

tyscof

#7
Dec 05, 2017, 07:48 pm Last Edit: Dec 05, 2017, 07:55 pm by tyscof
How did you set the accel rate in AccelStepper?
Can you post a link to the Velmex driver?
I didn't set an acceleration, doesn't AccelStepper do that automatically when not imputed?
I don't think it matters right now anyway since it vibrates even when it is at a constant velocity. But I could be totally wrong.

One thing though is that it doesn't vibrate nearly as much to at all when moving at faster speeds so it seems to vibrate only when moving slowly.

Driver:

 http://www.velmex.com/Products/controls/VXM_Controller.html

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