Pier base altenatives

[dph1nm]

Hmm. So for those of us who think burying a cubic metre of concrete in the ground is not terribly eco-friendly, are there any other ways of sticking a telescope in a roll-off shed observatory? I have seen an example of someone who just filled a plastic barrel with concrete and stood his scope on that. I have also had the suggestion of putting the tripod on three small concrete pads (with corresponding holes in the obs floor). Anything else?

I note that currently I use the tripod on a stone flag patio, and it is rock solid - vibration is not an issue for the sort of stuff I do.

NigelM

[barkis]

If you are an Observer only astronomer, then concreting in a Pier is not necessary, on the other hand, if you intend to image deep sky objects requiring longish exposures, then it is best to err on the side of a very solid foundation indeed. Any small, and I mean small, movements of the obs floor will impart itself to the telescope, and hence the image being captured. Star trails, even if they are small will spoil your work. Even tremors from a remote source could theoretically vibrate the mount pier if it is not well into the ground and fixed there. The human eye will accommodate small movements, a camera will not.

Ron.

[roundycat]

I used about a 22" cube of concrete with steel legs hammered into the ground underneath making the whole thing about three and a half feet deep. That is a heck of a lot less than a cubic metre. On top is a 200lb steel pier, an AP 1200 (90lb) plus 50lb of scopes and the necessary counterweights. All on Essex clay. Three years so far and no detectable movement.

Dennis

[Tim]

I am looking to do something like this very soon, however I have very soft sandy soil.

I am not sure where the notion of concrete being eco-unfriendly comes from though?

It is only made of sand, pebbles and cement, all of which are inert, natural materials. The ground will not be polluted, contaminated, or become inhospitable to fauna.

As Ron says though, if imaging is not your desire, the ability to keep the thing rock solid is not critical at all. In fact, I take 25 minute exposures on a mount on a standard tripod which is freestanding on a patio. I live next to an airport which occasionally hosts larger aircraft which rattle the windows, but have never noticed any effect of vibration on my pics, so maybe it's a bit of overkill?

Cheers

TJ

[Psychobilly]

Or one less thing to worry about...

[Paxo]

I am not sure where the notion of concrete being eco-unfriendly comes from though?

Cheers

TJ

It's the manufacture of the cement which is 'unfriendly' Tim, worldwide, a large contributor to the emission of greenhouse gases.

Back on thread, the suggestions you have made will be suitable for visual work, will you always be non-imaging, if not it may be awkward upgrading at a later date.

Steve.

[Catanonia]

I have my tripod on concrete 2x3 flags ontop of soil and sand inside my roll off roof observatory and so far I have yet to notice any movement in a max of 15 min subs.

I have drilled some holes in the flags to put the pointy tripod leg ends into so ensure it can't be nudged out of position.

However that all said, I have a completly separate warm room with a slight gap between the flags and never enter the scope section of the observatory when imaging.

To be honest, You will have more problems with the wind effect rather than ground effect. So I have nice high sides on my observatory to reduce this and LP as well. Helps that I can't see lower than 30 degrees because of house and hedges.

See my website for pictures.

[dph1nm]

I have my tripod on concrete 2x3 flags ontop of soil and sand inside my roll off roof observatory and so far I have yet to notice any movement in a max of 15 min subs.

Ah, so you don't have a wooden floor at all. That is an interesting idea. Unfortunately the commercial sheds come with floors (bouncy, bouncy), and I wasn't contemplating building my own.

As I said, I currently image on the patio (HEQ5 on tripod) with no vibration problems at all. I suspect sand is an excellent vibration damper - so flags laid on sand ditto. Given a tripod seems to do the job just fine, all this steel and concrete seems like overkill.

NigelM

[Catanonia]

yup was my take on it and hence the way I did it. Cheaper too

Cut holes in the wooden shed floor for the tripod legs

[skybadger]

I had both the obbo and mount bolted to a concrete apron behind the garage. The mount was isolated from the obbo floor. Whenever a lorry passed 100yds away you could see the vibrations passed throug the floor.

So I moved the obbo into the garden and dropped concrete underneath to mount the pier to. Seems to work fine.

regs

Mike