[nateman_doo]

https://www.youtube.com/watch?v=f6z0GCx0ML8

OMG its LOUD... but it WORKS!!

[the.sniper]

who cares its darn mesmerizing huh! when I first built mine I could not stop looking at them for day's.
good job did it solve the problem?
-S

[Bartos]

nateman_doo

what is your rpm max now?

could you please post exact dimensions of...?
diameter of the hole
diameter of the ball
distance of the hole from the center

Bart

[nateman_doo]

Not sure who here said it was difficult to make the part, but when you have a working CNC... its cake. I just turned the part down to a similar diameter, drilled a through hole, bolted it to the table, and hit the go button:

Harmonic damper CNC Machining - YouTube

[Poseidon]

It has been quite some time since someone added to this thread. I may be delaying the inevitable switch to closed loop drive systems but it was fun making these dampers. It is hoped that this will help with resonance issues coming from my NEMA 34 8.5 N-m drive motors. They are set up to directly drive 2005 ball screws for all axes of a G0720 conversion.

Initially, I had set the tuning of my motors way to high to get rapids of 4000mm/min. Steps were lost and projects ruined do to my carelessness in matching the capabilities of the motor and driver to the mass being moved. All motors have since been tuned to give rapids of 3000mm/min. Oddly, with the current settings, when I command a return to work zero coordinates both X and Y axes are driven at a rate of 4200mm/min without any loss of steps.

As mentioned above, my dampers are a stop gap measure to help with resonance issues before I relent and put up the funds for a closed loop drive system.

[nateman_doo]

i am in the same boat as you. The resonance is working its way into the product and not getting smooth edges.
I am looking into replacing my Nema 23 types. What are you looking into getting?

[UA_Iron]

anyone consider putting an oil lubricant inside the pockets to further dampen the rattling?

It would probably have to be thin, too much stiction might make it worse.

They lay out a good primer for reducing resonance in this youtube around 7:00 in
https://www.youtube.com/watch?v=4k3gZWpY_0s

In short:
1. Change voltage and current values going into motor - will shift resonance spot location RPM
2. Change inertia of load - which is what this thread is about
3. Change Microstepping
4. Motor Oversized for application


This is a great thread though, thanks for sharing!

[nateman_doo]

That dude is a cure for insomnia. Couldn't even make it 5 min into the video.

[Jimmy_H]

Sorry for waking up an old thread but, this just saved my whole CNC project. I cannot thank you guys enough for how relieved I am that this practically took away all my problems with vibrations. I had big problems with my dual gantry and the vibrations stalled one of the motors and if i increased the power it stalled at even lower RPM. So i gave this a try with a 3D printed screw on holder for 6mm metal pins and it worked awesome, I could go from 2000mm/min to my firmware set max at 4000mm/min (i had to increase power but this also worked flawlessly now that the vibrations got eaten up). So all in all, if you have problems with resonance this right here is one of the best information i can find. Also since my motors didn't have a shaft sticking out at the back i had to make min so it fit on the ballscrew. but it worked just as well as you guys had explained before

Cheers / Jimmy, a humble and grateful swede