Messages

21

General Mach Discussion / Re: Only X-axis motor is working

« on: April 07, 2018, 08:22:36 PM »

So, I'm looking at new components to purchase.

(I should start a new thread but this will suffice for now)

The stepper motors I'm planning on using are:
Dual Shaft Nema 23 with rated 439oz.in torque
Full Step Angle:   1.8° (200 Steps)   
Rated Current per Phase:   3.5A   
Holding Torque:   3.1Nm
Resistance per Phase:   1.1ohms   
Wiring Configuration:   4-Wire Bipolar   
Nominal Rated Input Voltage:   24 V, 48 V
Actual Rated Input Voltage:   24-48VDC

Power supply:
Wide Range 100-240V AC-DC 600W 48V12.5A
High efficiency, high reliability, low cost.

High 600W power to fit more devices.

Wide range of input voltage support, both of 100-120VAC
200-240VAC input voltage are available(Adjusted By Switch)
Adjustable approx 40-52VDC Output Voltage support.
PWM control and regulation, insure the steady and precise output voltage.
Built-in a powerful fan for cooling.
Built-in EMI filter.
100% full load burn-in test.
Over current, over voltage, short circuit and overheat protections.
Low output ripple and yawp.

Connected with either 16/4 wire or more widely available 18/4 wire.

I will be installing it all with aviation connectors from the control box to the motors.

This should give me the best, solid, system.

After all is assembled and I have a working machine (even if it has bugs) I will update the drivers and controller.

22

General Mach Discussion / Re: Only X-axis motor is working

« on: April 04, 2018, 03:25:24 PM »

I wouldn't do too much work if you are not keeping these motors - it will all change with new motors and certainly with new drives

Point taken.
Anything I do with these motors now is to gain a better understanding of things. I'm not looking for a solution, per second, but more of a path to a solution.

23

General Mach Discussion / Re: Only X-axis motor is working

« on: April 04, 2018, 01:44:15 PM »

I did some reading and watching of YouTube videos and have a better understanding of resonance and I am convinced my problem is just that. Resonance.

Now I will be exploring the various methods of removing the resonance factor.

Thanks for pointing me in the right direction.

24

General Mach Discussion / Re: Only X-axis motor is working

« on: April 04, 2018, 12:49:43 AM »

Multi-stepping is your best chance.

Cheers
Roger

So far multistepping gave the most promising results.

25

General Mach Discussion / Re: Only X-axis motor is working

« on: April 04, 2018, 12:08:23 AM »

There are several ways to deal with resonance - I think I mentioned this earlier.

* Never go near it (stay slow) It happens at a very slow speed
* Try to make a mechanical damper to fit on the shaft (negligible likelihood of success) Then I won't bother with it
* Try to damp it down with a toothed belt and a lead-screw (with LOTs of prayers) Then I won't bother with it
* Buy a modern driver which includes electronic resonance damping. In time, in time....
* Use a bi-phase sinewave drive rather than steps. This may or may not succeed, and is almost the same as using a modern high-order micro-stepping driver anyhow. Then I won't bother with it

Cheers
Roger

In the meantime, I'm going to play with multistepping and/or underclocking. It's possible that my drivers are over amping. I don't have a way to test that.

26

General Mach Discussion / Re: Only X-axis motor is working

« on: April 03, 2018, 11:22:19 PM »

Resonance?

I took the 3 amp motor that was working fine on one amp, and hooked it up to 3 amps.
 
It suffered the same symptoms as the 1 amp motor at one amp.

So... resonance?

How do I keep my new steppers from not doing this?

I'm going to play with underclocking.

27

General Mach Discussion / Re: Only X-axis motor is working

« on: April 03, 2018, 11:19:23 AM »

Well, if all the steppers I have are dead then they're dead. I wasn't going to use them for the final project anyhow. I can still use them as generators for a water powered light show (if I ever get around to that project).

I had intended on  using new steppers anyhow so might as well get it done.

I'm still going to do the whole oscilloscope thing and I'm going to step my driver up to 3 amps on the working motor to see if I get hinky results. After all this is all a learning process for me.

I know I have another new stepper out in my garage so I will test that one also. It's connected to a balls crew already which is why I haven't used it til now. It's pretty bulky to play with.

28

General Mach Discussion / Re: Only X-axis motor is working

« on: April 03, 2018, 01:55:35 AM »

Yup.
It's a hard world: you have four choices:
Hope that the assembled system (ball screw etc) will damp it down enough
Figure out a mechanical damper (no-one else does this)
Stay below 45
Buy a new driver like a Gecko 203V

Cheers
Roger

OR, I could get new stepper motors.

I just hooked up a 3A (using my driver set to 1A) 6 wire stepper motor and it worked flawlessly.

I'm thinking these are just weird motors.
I'll do more testing tomorrow but it seems like the motors just don't like to work "normal".
I have a couple other motors that aren't like the other 25 so I will check them also.

29

General Mach Discussion / Re: Only X-axis motor is working

« on: April 03, 2018, 01:25:35 AM »

Works fine at anything under 40 or over 55.
But it HAS to accelerate past 45 to gt to anything over 45 and it always messes up on the acceleration.

I tried to buffer the possible resonance with my finger and thumb giving various levels of stability and the motor is VERY persistent on making the steps as you see in the video.

30

General Mach Discussion / Re: Only X-axis motor is working

« on: April 03, 2018, 12:41:00 AM »

A video is worth a thousand words

https://youtu.be/5s0y1Pj-8JM