Peter, I’m glad you asked this question, I’ve also decided to install a pier for a potential observatory and was thinking how to secure it also. I guess Doppler makes a good suggestion- this would certainly hold the pier down no problem but I’m curious to know if this would be sufficient to prevent it from wobbling under the weight and motion of my heavy Newtonian. Tripod legs have a wide span to balance the shifting weight however the tall pier lends itself to movement? Question I’d like to hear people’s opinion on. Sorry if I have added this query on your post Peter but being topical and timely we may both gain from the experiences of others that have had success in their pier mounts.
Would you need to fill the pier with cement or sand - would that stabilise it?
Best wishes for your obs/aero pad Peter.
Anthony