Building an observatory pier

From another thread...

At the moment I'm building an observatory at home in Meath and would like some advice about the pillar for the mount. I know some people who have done this and have filled the pillar with sand to cut down on the vibrations, does anybody know what kind of sand would be best? I.E coarse or fine, wet or dry?

I asked a similar question a couple of years ago and the replies are still at

groups.yahoo.com/group/irishfas/message/1120

I never got around to doing it, but other may have experience to speak from.

Cheers,
~Al

We are hi-fi buffs too and my brother Nigel built a pair of Side vivace enclosures for Lowther DX-3 drive units.

The enclosure was for a single horn-loaded drive unit and this required us to make a horn to amplify the bass from the single drive unit. The gaps were filled with play sand which was dried out in our boiler house over a few weeks. Play sand is used as it is sterilised and nothing will start to grow in it!!!

Use a thin stick to attack the sand as it settles in the tube. After you fill the tube, you will find that it takes a few days and some stabbing with a stick to get the sand to settle but it does work.

Gary Nugent did a piece in Orbit within the last couple of years on the construction of an observatory. He in fact gave a talk to SDAS (back in Kenilworth days) as well.

That might be of some help.

Thanks for these replies. I'll check out the links for ideas.

Cheers

Spaceboy.

As well as Orbit, Gary has put similar articles into his own pdf ezine Photon. www.nightskyobserver.com/Photon/

issues 1 and 2 have articles describing the observatory, though I think he bought a pier.

Hi Spaceboy,
I built a pier about 2 years ago for the 12",
It consists of a metal tube 6 feet long and 10 inch in diameter, the metal itself is 5/8 inch thick steel, its a serious weight!.
Then I got a local metal working company to weld on a square metal plate onto each end, each plate is 16x16x1 inches of steel.
I then got the entire thing hot dipped galvonised and then I painted it black using hammerite.

I had holes drilled onto each plate so that one end could be bolted into the ground and the other end could have another plate sitting on top of it using 4 thread bars +bolts (3/4 inch thick), this top plate could then be precisely leveled using the thread bars, and I had holes drilled in it so it could accomodate a wedge.

The reason why I used a barrel (aka supergun) 6 feet long was that I could bury half it in concrete if the need arose, to dampen any vibrations. It sits on a foundation 3 feet thick which sits on bedrock. It could easily accomodate a much heavier scope. Its rock solid and I can lean against it while using the scope with no noticable effects.

I had a hole made 2 feet from the bottom where i fed up a conduit for wires, so there will be no wires around the pillar. I filled the internal cavity with normal sand, there are no plants coming out of it yet

An observatory is going to be built around this over the coming months.
This might be over the top for alot of scopes, but its an idea of what you can do.
I'll put up a pic tomorrow.