Z axis threaded rod vibrations

Hello,

yesterday I printed an object with 1.5mm walls. The printed object came out quite well, but Skeinforge decided to put a zigzag infill into the walls. This resulted in very small x axis movements, may be 1mm, back and forth, which excited the z axis threaded rods to resonance vibration. I had to put a finger on the top of the right threaded rod to avoid bumping to the upper right z axis clamp. After the print was finished I discovered, that also one of the z axis coupling screws became loose.

Is there some possibility to convince Skeinforge not to put this type of infill to thin walls?
Or is it better to reduce the acceleration settings for Marlin?

Regarding the Z axis couplings i saw some couplings in the Web (please see the attached files).
People use them also for threaded rods at home made milling machines, so I hope they have very low backlash. They are available with adaptors for 5mm shafts and for M6 threads. The overall outside length with the adaptors is 44mm. So may be I will loose some millimeters of maximum Z axis travel.

Has somebody experiences with such type of couplings?

I think changing the acceleration in Marlin from 4000 to 2000 fixes any problems with resonance.

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[www.hydraraptor.blogspot.com]

Rather than have to change Marlin I just put
M201 X2000 Y2000 ;max acceleration in X and Y
in start code. I confess to a pathological hatred of Arduino!

Thanks for the hints.
My M90 now is printing much more silent ...