Re: Pier for 1100GTO #Guiding


Len Fulham
 

Embedded or bolt attached pipe piers are commonly and successfully used, but they have an inherent tendency to resonate vibration. Filling with sand or concrete changes the frequency and maybe amplitude without necessarily improving damping as might be expected.

The best piers have a broad base tapering progressively to the top. This form minimises the tenancy to resonance and is self damping. It is not a good shape for embedding, but works extremely well for bolted applications (eg bolted to a concrete base).

Look at this example:

https://ap-ug.groups.io/g/main/photo/113262/13?p=Created,,,20,2,0,0

The pier has a 600mm square base bolted to a isolated concrete foundation. The pier tapers exponentially to 150mm square at the top. It is made of 6mm thick mild steel. It forms an extremely stable base for the vintage AP 706 mount and 6" AP scope.  It takes more to organise a pier like this but it is appreciated in the long term.

A simpler "tall pyramid" shape (ie tapered flat sides rather than curved & profiled)) would be much better than a pipe, and could more easily be made embeded.

Something to consider,
Regards,

Len.

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