steel Pier design

[I.C.D (Ian)]

I have read a lot about people wanting to make a pier to mount their telescope on .I hope the following will help.
Step 1: The base plate should be no less than 12 mm thick the thicker the bass plate the more stable the pier will be
Step 2: The pier can be made from any steel pipe no less then .100mm (D) the thicker the walls the better and less vibration .My Pier is .100mm D x .900mm H gal pipe with 2.5 mm thick walls and I have half fill it with sand .Other pipes which you can use are steam or black pipe which have 5 to 6 mm thick walls, and If you know someone who works with conveyor belts a return roll from conveyor belt make’s great a pier. I have seen a couple of piers made from these and they look good
Step 3: The top plates are up to you. I have two the first plate is welded to the top of the pier the next is bolted to the bottom plate this allow me to level the telescope and to raise or lower, the bottom plate was drill with a 12mm and he top plate was drill so I can tap and thread it for a 10mm x .150 mm long thread bar.
Set 4: Welding should be done by someone who can weld the reason being the last thing you want is the pier to brake at one of your welds and your telescope laying on the floor broken .For a couple of hundred dollar’s it is better than a couple of thousand for a new telescope,
Ian C

[bugeater (Marty)]

I made mine from:
1 x Pipe Galvanised Medium (90NB Med Gal (101.6 OD x 4)) - 100mm - $4.96
1 x Pipe Medium (150NB Med Blk (165.1 OD x 4.8)) - 700mm - $42.48
2 x Flat Bar (200 x 6) - 200mm - $18.10
Total: $65.54

Welded it myself. Perhaps I'm being over confident, but I have no fears of weld failure given the load it will be holding. I did multi pass filter welds with an arc welder. From what I've heard there can be issues with MIG welds not getting enough fusion, but less of an issue with arc as long as the weld looks okay.

[rally]

Ian,
This is adequate for visual use where mechanical support of the gear is really the only thing needed , however rigidity/stability is the important issue for AP to transmit all vibration and movement to ground and depending on the height of the pier, a greater wall thickness and larger diameter is the way to increase the rigidity.

The byproduct of this rigidity is greater strength which is unnecessary, but you cant get the rigidity without it.

The extra cost is almost insignificant especially if you buy salvage/recycled gas pipe which is commonly available and its unseen.

[jenchris (Jennifer)]

Steel is a renowned vibrator unless you mix it with something else.
I used a plastic water main pipe which is 230 od 200 id filled with concrete and four reo bars.
It's 5 foot high ( plus 2 feet in the concrete foot) and has no resonant frequency. It deflects not at all is a pretty blue colour and cost me nothing. Any building site new development will have offcuts you can scrounge.
The ratcage is two discs cut from 15mm steel, also scrounged, from a local metalwork shop