Pier Rat Cages

[Logieberra (Logan)]

Here's a few pics of the pier that Brendan mentioned. I went as big as I could afford which has worked out for the best. I was planning on an AP Mach1 / 900GTO but ended up with a MX. Either way, you can't go wrong with a pier that exceeds your current requirements... it will serve you into the future.

http://db.tt/N1aq7N5l

What you can't see from the pics is the floating top plate. This top plate is connected to the pier top plate by 4 x M16 bolts. I am currently getting the floating top plate tapped to accept the MX base plate knobs (4 x 3/8" @ 24TPI). Again, as Brendan mentioned, with a change of mount I can always get a new top plate cut and tapped.

[bcoote (Brian Coote)]

Looks completely solid. What I don't understand is why you need a floating top plate added to this? What is the benefit?
Brian

[Logieberra (Logan)]

When I say floating, I don't mean rat cage with room / air between the two plates. They are sandwiched together, 340x340x20mm plates on top of eachother, secured by M16 x 4 on the corners. As I said, I can butcher the top plate to suit my current mount, drill, cut, paint, tap - whatever. With a new mount down the track I only need to replace that upper plate. The pier itself remains perfectly blemish free. Suppose my local machinest stuffs up the tapping of the MX holes, the only damage is that single top plate, not the overall pier. Makes sense to me... Long term pier, short term top plate.

[Logieberra (Logan)]

Sorry for spelling, hard to type on Android phones...

[bcoote (Brian Coote)]

I'm sorry I was thinking you were going for a plate standing on four 16mm threaded pillars.
I did basically the same as you intend with the top plate for my AP1200 GTO mount. The mount was 2nd. hand and I got a machined top plate with it from the vendor. Apart from anything else this gives a dead flat machined plate for the mount which you cant be sure of with a welded pale on the column.
I did stand my old traffic light mount on 4 x 1 inch shafts which I used to adjust to try and keep the column vertical. This was only to try and minimize Polar alignment drifting without any great success. This mount is only use for short FL stuff mainly with FSQ or even camera lenses. With short FL imaging Polar alignment is hyper critical so that for me anyway even with perfect guiding stars in the corners of a big chip show definite rotation on anything longer than 5 mins whereas 30min integrations on 2.8 meter FL is no problem.
Can't see you having any worries with that mount and column
Brian