About to build my pier base this weekend.

[merlinxlm]

Hello everyone, I'll be building my pier base this weekend. I'm constructing it out of a 20" square by 15" depth, filled with concrete. I'll then be sinking four 12mm threaded rods with bends in them, into the concrete base. My question is, what type of sand to cement ratio should I use and is the 20" X 15" to big for my equipment? My mount it a SW EQ6 Pro with a SW 80DS pro OTA, plus a ST 80 guide scope. I will be buying a Celestron C9 1/4 OTA, next year. Would a depth of say 10" be sufficient?

Thank you for looking.

[Bizibilder]

Make the concrete base as BIG as you can!! 2 foot square and at least 2'6" deep or bigger - you want LOTS of mass below ground! The mix should be around five ballast (not sand) to one cement. You can buy 25Kg bags so it is relatively easy to get the proportions right. The mix must not be too wet or dry - the test is if you take a shovel full it should "retain its shape" on the shovel and not sink into a cow pat!!

You really must go deep with the base - don't forget that you are adding quite a bit of weight to the pier top which will act as a very good lever that is trying to shift the concrete base - especially if its windy or you lean on the scope. 10" or so simply is not deep enough.

That is a good looking pier - looks like youi had it made up as a special?