Aluminium/Stainless Steel Pier

[Raymond]

Dear all,

I am planning to tailor-make a metal pier to be placed at the building roof top for my TEC140 F7 refractor (with imaging gears 26-28lb; and 40-inch long with dew shield fully extended). Concrete pier is out of the question.

If a 36-inch long metal circular tube (wall thickness about 1/4 inch; and about 6-8 inch diameter) is to be used as the vertical pier, which metal (aluminium or stainless steel) would have better damping and stability properties ?

I plan to use 3 metal legs. Each leg will be about 24-28 inch long. Again, which metal (aluminium or stainless steel) will be a better choice in terms of rigidity ?

Thanks in advance for comments.

Raymond

[Striker (Tony)]

I'm no pro....but filling up the pier will make a big difference.....more so then the type of steel used.....mine is very solid which I filled up with river sand.

Mine is 44" high by 13" diameter in stainless...the walls are only around 6 or 7mm thick.....

I personaly would go for a wider diameter pier...6 inches is too small.

This is my opinion......others have smaller piers that seem to work.

[gbeal]

For no real reason I have a steel pier, 5mm wall thickness, and only 600mm tall (above ground). It handled the G-11 well, and now carries the EM200.
Biggest question is what mount, and how you will attach it to the pier, as this can often be the weakest link.
I agree with Tony, 6" is a tad thin, but in my case it has been sufficient.
If weight is not an issue, and I believe the heavier the better, down low, then go steel, all round. It is also interesting to note (from memory) that AP portable piers are alloy tube, with steel legs, if I remember correctly. There must be a reason.
Gary

[Raymond]

Dear all,

I forgot to mention the mount. It is Tak's EM200 Temma 2.

It appears that sand-filled steel tube is the way to go. I am considering a 8-inch diameter, but 10-inch diameter may be a bit big for the present moment.

Raymond