Rail Resonance / Vibration

I have a coreXY machine that is build with MGN12 Chinese Rails.
I have been having issues with alot of sound / resonance during printing.

I added some Nema 17 Dampeners and it really decreased substancially.. its not all gone but a big improvement.
I suggest anyone with weird vibration/ resonance sound issues to install a pair on your XY steppers

---

Makerparts.ca
Your Canadian source for V-Slot Extrusion, CNC and 3D Printing Parts and Accessories.
we are proud to be an official Openbuilds distributor.

Has it affected print quality?

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I using too linear rail 15mm and i see some resonance but only in low speed print, normally i get them on the first layer (printing at 30mm/s).
Use of damper remove some resonance but also add elasticity on the belts that can affect the precision, so.. not sure if is a good option to use them.
One way to reduce these vibrations and increase precision is using steppers that was high steeping values, instead of the normal 1/16 or 1/32 use one that allow 1/128 or better. You can use motor with 0.9 degree too instead of the 1.8º.
Other reason can be the related with the quality of chinese rails you are using.

But at the end i pretty sure almost all printer was this resonate at some print speeds. One way to avoid them is to determine the range of speed the resonance do not happens and start to do your print speed in this range.

Edited 1 time(s). Last edit at 10/14/2016 04:55AM by filipeCampos.

... you can see it in a simple relation -- the cheaper the rails, the louder/weirder the sounds

What's making this sounds are mostly the balls not only rotating, but too "shaking" in the feed, when they're a bit smaller than the gap.

With "good" ball bushing rails the balls are selected for uniform size and geometrical precision.

WIth the cheaper parts the size of the balls can vary slightly (up to some ten microns!), so there's an undefined assembly of bigger and smaller balls in the feed, where the bigger defines the gap size, while the smaller can "totter" around in the gap and between the two neighbouring balls -- this will mostly be the source of this weird sounds.

Best (expensive) rails are not only preselected, but too "precompressed", so the balls are all pretty uniform and slightly bigger than the gap size, so no room to jump/totter or to make noises (beside of a constant "hiss", what's normal for rotating steel balls on steel feeds). But then too you'll need much stronger/beefier motors to drive them, than common with 3D-printing ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]