Telescopes and violins

[bojan]

The violin makers are experts in design and making the resonant cavities of string instruments to produce a loud and beautiful sound..
However, I have quite the opposite problem - how to reduce and dampen the acoustical vibrations inside the newtonian tube (tube is fibreglass and vibrations are produced by stepper motors when tracking), which are destoying the image quality at high magnifications... I believe the most affected part is secondary mirror, and that the problem could be possibly solved by inseting the baffles (which material?) at appropriate spacings inside the tube.... Motors are already mounted on the rubber absorbers, so the noise is already reduced at its source as much as I possibly could...
Any ideas and solutions to the problem will be most appreciated...
B

[Astroman]

You could try Newt25.zip for working out where the baffles can go, this can be found at http://www.dalekeller.net/atm/newtonians/newtsoft/newtsoft.htm

I used rubberised foam with sticky backing in my 8" f7 Newt, worked great as light baffels aswell as a sound absorber. you could always wrap a couple of bits around the outside of the tube too, to absorb the sound waves.

[bojan]

Andrew, thanks for your input.. I was thinking about stcky rubber but I am afraid this will be a messy solution as this glue sometimes stops to be a glue in very unpredictable way.
Perhaps polyuretane foam (out of can) can be used, provided I manage to contain it where I need it somehow..

[jjjnettie]

How about making up a sleeve of wetsuit material. Just slip it on.

[bojan]

Hmmm sounds like a good idea... I will try with elastic bands arount the tube.

[Rodstar]

You should ask Peter Read (SDM). He is a violinist as well as a telescope maker!

[bojan]

Hi might be the right person to talk to about such a problem :thumbsup: I already tried to talk to my daughter's violin maker, but he is not telescope maker..
How can I contact him? It seems he is not a member of IIS...

[Rodstar]

Bojan, his website is www.sdmtelescopes.com.au, or call him on 0421 653 747. He is based in Shepparton VIC.

[bojan]

Rod, thanks a lot !! :)