I find this thread slightly be-musing. When I put my pier in for the observatory I realised that since it was located on ash residue from mining and clay it was unlikely to remain level either after it set or with the passing of time. So I buit it as shown in the thread
http://www.iceinspace.com.au/forum/a...se.php?a=72246
It has proven its worth over time for ease of adjustment in its initial setup and subsequently as it appears the whole shebang is slowly sliding down the hill due to the soil constitution.
I dont experience any resonance with my G11 or heavy scopes imaging at 2500mm for 15-30 min.
The maths may be there to say it should flex, resonate or whatever but my experience says this is not the case.
Its a bit like bumble bees mathematically proven not to be able to fly.
Just my 2c from experience.