Rick,
The strength requirement of a pier is the easy part of the pier design, and what you say is true.
But the other main function of a pier (at least for astrophotography) is also to transmit any and all movement and vibration to the ground, that requires much greater rigidity, which has the unnecessary byproduct of being over engineered as far as strength is concerend.
So there is a point to it, but its not for strength.
Of course if there are weak links in the chain - eg rats nest on little M12 threaded rods, mount backlash and high PE then the quest becomes less useful, but its all about progression, so building the cheapest part of the system (pier) to be a strong link rather than a weak link makes sense as you are only arguing about loose change by comparison.
Maybe $50-100 or less and a bigger hole = more labour !
Quote:
Originally Posted by doppler
I think that any sort of pier has to be much more stable than the foldable tripod legs that come with most mounts. The only way my rig is going to fall over is if the single central bolt that holds the mount down breaks. No point in constructing a pier that can support 1000kg when you are only putting a 40kg payload on it. Most piers and their concrete bases are probably way over engineered.
I have a rats cage top and the pier is concreted in with only a wheelbarrow and a half of concrete. No stability issues here with a 10' newt and 20kgs of counterweights on top.
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