Reply with Quoteproject5k, 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
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...
Grizzly X3, CNC Fusion Ballscrew kit, 3 500oz-in bipolar steppers, 3 203v Gecko's, Linear power supply from Hubbard CNC, Mach 3, BOBcad Pro Art V22, Rhino.
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
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.
Grizzly X3, CNC Fusion Ballscrew kit, 3 500oz-in bipolar steppers, 3 203v Gecko's, Linear power supply from Hubbard CNC, Mach 3, BOBcad Pro Art V22, Rhino.
Adding a shaft to the end of the motor
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.
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!
50 IPM missed steps
65 IPM motor gets really unhappy in this one!!!!!!
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
Thank you for the videos ! Very imppressive to see how powerfull they are...
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
Fixitt... aweseome job on getting this to work. Looks sweet.
Thanks buzz......
hind site being 20/20... I dont know why I didnt do this years ago. Would have saved alot of head aches and cursing..... I am very pleased with how the machine runs now.
Last night I ran a test wax at 55ipm that took hours to machine. There is no way I would have tried this before. The wax looked good. but 55 ipm is still pushing the envelope for this small desktop unit. So I did the same wax again at 35 ipm Still would not have done this before and it came out better. Then at 40 IPM same code. Just as clean as the 35 ipm unit.
Very pleased to say the least!
Hi,
Thanks SJH for bringing the light onto this dampener issue.
Also, Fixittt, thanks for your very impressive video. The damper there looks rather simple. Is it just a bar with two screws and a few washer at the ends? Does the micro-stepping help with this resonance problem?
Regards
David
David, what I used in the videos is a fixture I had made for holding wax tablets. It just so happened that I could easily adapt it to fit on the stepper. The reason I used the washers on the bolts was to give it the "RATTLE" effect that seems to adsorb the resonance. As I stated, it was a crude 3 A.M. experiment but proved to work.
All my videos were done WITH micro stepping so I guess to answer your question. Micro stepping does NOT help with the issue alone.
Hi, thanks for your reply. I had a mis-concept that the micro-stepping could save a stepper from resonance, but I still got the stepper stalled with a micro-stepping driver. Now I shall try this rattler to see if it helps. It's really impressive that the little washers could make such huge difference.
its alot easier to understand if you understand what is happening in the motor.
When the motor rotates, its creating a vibration due to the indented torque. A stepper spins by taking alot of very small steps. This vibration is in a certain frequency range. These vibrations can build and build inside the motor until it becomes so bad that it misses steps. Machine design plays alot in this. Weight, resistance ect. The washers or rollers in the dampener "RATTLE" due to the vibration, So, the energy created by the resonances is absorbed as it is transferred from the motor to the dampener. The very basic idea behind the dampeners is to get that wave energy out of the motor and into something else........
A little googling came up with this:
http://www.rino.co.uk/products.asp?recnumber=1232
there were some other more expensive exotic dampers around as well.
anyone know of any other reasonably priced commercial dampers?
Rubber Dampers ??
Anybody ever try making rubber dampers of some sort before ??
An other type of damper
I use a damper of a little different construction:
It is complete silent and not so difficult to manufacture. Other advantages are that you can change its data easy by putting in different viscous grease and that its flywheel also slips when accelerating.
It consists of thin disk mounted on the motor shaft. The disk is then encapsulated in a freely moving flywheel and the space in between is filled with this grease.
Last edited by elile; 10-30-2007 at 02:54 AM.
i dont even have a cnc but i have heard of mid-band resonance and was dreading it, if i ever get to build a router,those video's really show how it helps to have a damper,i never knew what such a thing as resonance was but (still not really sure),i like david geng, had heard microstepping would help,but that damper really proves a simple fix can go along way..
"witty comment"
SJH and SteveTee a huge thanks!! I just found this thread and hopefully once I create my dampers it will cure what I guess has been a resonance problem I've been having. I too only have a single shaft but after closer examination realize I can drill into the back of my motors. Thanks again and i,ll post pics and results upon completion.
Hell all, Im too am having problems so I had to slow it down a bit and it seems fine . my ? is this , would a modified hokey puck work as well.
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