I know I am going overboard with my Pier......but when it's costing me Nothing...why not...and I would much prefer to go to big then too small....never know when my next upgrade or accessories could be....lol
If I had to pay the $1500 for my pier then I would of probably glued a few Aluminium cans together and called it a pier...or maybe not.
Everyone will have their own opinion...as long as your happy with yours then thats all you can ask for.....
Just from what I have read up and seen....the piers on this forum do seem to be too small by a fairly large margin....but like I said...if it works...good on them.....I'm not going to publicly knock anyone's Pier...if they didn't work I'm sure it would have been pulled down by now....
P.S I have received everything today accept the Astromeccanica set....
The rigidity of a pier would also vary a fair bit depending on what material its made from. Stainless steel and mild steel are not very rigid or hard compared to higher grades of steel. That said it's probably cheaper too buy a larger diameter of mild steel than a smaller diameter of something tougher and stronger. But when it's free you can't complain.
It comes down to weight of it filled with either sand or concrete that reduces the "Q" factory.--vibration and flexing.
The pipe in reallity only a container to hold the mass but in some cases will add stiffness.
You can use card board form tube (sonotube) filled with concrete and rio bar .
The form tube being discarded later.
Also use form ply and make a free form square base of concrete and rio bar and again remove the form ply.
A concrete storm water pipe is relatively cheap $100 depends where you live. Again fill this with concrete.
Many cheap alternatives are available for a solid pier .
Tony's is steel steel filled with sand mainly because he may one day need to move and doesn't want a permanent structure left behind.
Paul...I was wondering what you were referring too....but now when I think about it....I imagine you mean the Mapleton Observatory.....I honestly didn't even look at the Pier at Mapleton but I do remember the cone shaped upper section like what I have suggested.
I was planning on doing a different plan until the neighbour suggested this........but you can take the credit...Paul.
Here ya go. this is viewing it from side on, front on the shape is the same as tony's. The pier is black so I've adjusted the contrast and brightness to bring out the details a bit better
Hi Guys ,I built my pier before I built my observatory, the pier in the first picture is a 90mm steel pipe buried 1mt into the ground filled with Mary river sand,the hight is also 1mt, it still vibrated so I surrounded with a concrete casing 20inches in diameter with a spacing if 12mm thick rubber 100mm wide which is the thickness of the concrete floor which the observatory was built on, It doesn't vibrate any more
The scope is a 20cm Celestron Ultima 8 purched in the USA in 1990.
Now those are piers to be proud of , glad to see no flag poles
The Mapelton pier is a work of art and from seeing it close up works fine .
How big is that pier for the 11"Paul??
I'd have to go and measure it Mark, but the following image should give you some idea of its dimensions considering its a C11 scope.
The lower concrete part of the pier extends a further 1meter below the floor to a 1m x 1m x 1m concrete footing that is separate from any other structure. Even the part coming through the floor has about 15mm gap all the way round to keep it isolated from the observatory floor.
Originally posted by Jonathan The rigidity of a pier would also vary a fair bit depending on what material its made from. Stainless steel and mild steel are not very rigid or hard compared to higher grades of steel. That said it's probably cheaper too buy a larger diameter of mild steel than a smaller diameter of something tougher and stronger. But when it's free you can't complain.
While the strength of various types of steel varies greatly, the stiffness is pretty much identical.
There's a big difference between stiffness (modulus of elasticity) and strength. Hardness is related to strength.
The larger diameter section will have a much greater bending stiffness and probably strength (it depends on the size difference) than the small one.
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Clad there's no copyright involved 
you couldn't have gotten it closer without tracing it. 
