My take on a stepper damper

[twice2]

I guess one could try filling the pockets with fishing sinkers, lead split shot etc...
Here are my files.

[Oldmanandhistoy]

Just a quick post to say thank you to Steve aka S J H for this thread. It inspired me to do some thing I would not have dreamed of trying before. The results are way beyond my expectations.
Using the resonance damper described here has make my X axis go from unusable (because of resonance and high motor inertia) to a system which gives my 7m/min (275”/min) rapids (machine has more but I don’t want to push it at this stage; still setting it up) of smooth motion. This is with a stepper motor, Trapezoidal screw and a drive with no mid band resonance suppression.
It is a remarkable device that makes drives with MBRS unnecessary imho which every one should know about.
One last thing I made it from 1” MDF with steel rollers just for test purposes and it works a dream. I plan to cut one from aluminium using my new machine.

Thanks again,

John

[S_J_H]

John,
You are welcome! I have not checked this forum in quite some time and just saw this. I am very glad this helped you!
Steve

[S_J_H]

Sorry I missed your post Mike! I am very glad they worked for you as well!

Steve

[project5k]

ok, so i have to ask this question.. since im using 500oz motors on my x3, im concerned that i may run into a resonance issue as well.. they will be direct driven, lovejoys, so i'm wondering if putting this damper on the far end of the screw would have as good of effects.. i ask this, not to be a pain, but i'm afraid that my setup wont have room enough to allow me to put it on the motor end, and my motors are single shafted...

[S_J_H]

project5k, yes I think it will work fine. Why do I say this? Well on my belt driven Y axis the damper works just as well on the screw(driven end) than on the motor shaft(drive end) after much testing.


Steve

[project5k]

thats good to know... I'll have to see if my cnc fusion kit has anyway for me to attach to it, once it gets here... I wonder, what would be the best way to go about making one of these if you dont have a rotary table... i can see turning the outter body on the lathe, i can even see using that to set the centerline for all the holes, but i just dont think i have the tools to draw out the holes and drill them evenly spaced... i wonder if i could print something off from the computer, and then just center punch through the paper onto the turned body, then try my best to drill them straight on my elcheapo drill press... or i guess i could drill them on the mill.... wish i had a RT.

[Steve-Tee]

Seeing how the damper imparts an amazing calming effect upon the motor, I thought I would try them in my build.
Problem, no place to fit them.
As the motors are only single shaft types, there appeared to be no way to mount the damper on the rear of the motor.

Well, to my delight, I found that it's really easy to bore a hole up the length of the motor shaft.
I simply mounted the motor into the lathe chuck, and treated it as if it were nothing more than a piece of solid stock that needed boring.
This lets the motor work as it always did, but now offers a way to attach a shaft to the rear end of the motor.
This may be threaded, or pressed into place.

I hope this little detail will be helpful


Best wishes,
Steve-Tee.

[Fixittt]

Well I have to say I finally did it. I finally made my dampeners!!!! After chasing that damn stalling gremlin for a few years I finally made them! I made mine from Delrin. and instead of using rollers or pins I used 1/2 in ball bearings. I noticed that alot of the designs call for around .40 clearance on the holes. Seeing as I am using a maxnc in my computer room, I was afraid that it would have to much rattle so I used .20 clearance on the holes. probably not nominal but it works just fine for me. I have had my little macxnc 15 running micro stepping with 1/4-20 TPI acme screws up to 65 ipm before it starting complaining again. I am running at 45 ipm and its stable and seeing as when I bought the machine it would do maybe 15 IPM. its a great increase! I am cutting wax for jewelery so I am able to cut at that speed with no issues so far (Famous last words).

I think what finally made me do it is the other night at 3 am I was 6 hours into machining a ring and my Z lost stepps. Pissed me off. So I make shifted out of brackets ect I had laying around a dampener. It cured the issues right away. The dampener was ugly and wasn't going to work, but it was great for testing.

Anyone trying to solve the infamous XYLOTEX motor stalling problem....... I have done it all already. The dampener is the only way to go!!!! Here are some videos to show the effects with my cheesy thrown together dampener.

20 ipm the resonance was bad. No MACH 3 settings were ever changed!
http://www.youtube.com/watch?v=9RoOZs9LrYo

50 IPM missed steps
http://www.youtube.com/watch?v=ivDQTeGuduk

65 IPM motor gets really unhappy in this one!!!!!!
http://www.youtube.com/watch?v=8Am69_F93yA

[P.Passuello]

Unbelievable results, the video says it all.
I am very impressed. I see you have some bolts with washers out the side. Is this just a test unit and you have now built one with bearings, or are there bearings in the unit on the video?

Cheers
Peter

[Juka]

Thank you for the videos ! Very imppressive to see how powerfull they are...

[Fixittt]

That is just the CRUDE test fixture I threw together. Once I seen how effective it actually was I made those videos, I knew I had to fab some nice ones!!!!

Originally Posted by P.Passuello Unbelievable results, the video says it all. I am very impressed. I see you have some bolts with washers out the side. Is this just a test unit and you have now built one with bearings, or are there bearings in the unit on the video? Cheers Peter