[Auster1b (Neil)]

G'day, I have started excavations for our observatory and pier footings, finally a permanent setup - no more carrying.

The Obs. will be an elevated and Maxdome automated Sirius 3.5m housing a 14" LX200GPS on a Meade Ultrawedge at 36.8 deg South, but before I go too far and fill a bloody big hole with concrete I would like to check that I am on the right track in regards the pier location.

Having always used Alt/Az, this Equatorial stuff is a learning curve, I have modelled the setup in CAD, but with no practical experience I would appreciate some feedback/comments:

From what I understand, I should locate the Optical tube and Dec axes at the dome center, calculating back from here gives me a pier offset 275mm to the North.

Looking at future possibilities, Equatorial mounts do not appear to require this amount of offset (PME, PMX, etc) and given that the rigidity of a fabricated offset plate should be solvable by design:
If I was to place the pier central, would the 275mm offset plate mounted on top introduce a physical obstacle to observing with the Meade?
If I was to place the pier 275mm North, would an offset plate to the south then be an issue with the mount/counterweight shaft or more likely the scope on an Eq mount ?

The Sirius 3.5m should give us enough room to swing a cat, so clearance should not be an issue, but how does this offset or lack of it affect dome slot alignment (the 1000mm slot opens 400mm past zenith). Could this create an unresolvable alignment ?

And finally, what other practical issues have I missed ?

Thanks for your advice, Neil.