Erik, To get the shape of the base the way I wanted it. Dale ________________________________ From: "erikhansen@thebluezone.net" <erikhansen@thebluezone.net> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Mon, May 10, 2010 10:40:55 AM Subject: Re: [Utah-astronomy] Kicking tires eerrrrrrr piers
Dale, Why did you do the pier in 2 pours? Erik
It looks like the pier is concrete, in which case disregard my
suggestion. I had thought it was a steel pipe initially.
A hollow steel pier filled with gravel will dampen vibration almost instantly as opposed to a hollow pier. Sand works very well, too, but it tends to clump and solidify with time. Once solid, it loses it's vibration damping properties.
You might think it counterintuitive, but the gravel-filled steel pier resonates less than a solid concrete or concrete-filled steel pier.
On 5/10/10, erikhansen@thebluezone.net <erikhansen@thebluezone.net> wrote:
How deep is the pier sunk in the ground? I initially filled in the area around the pier with gravel, but I have since filled it with concrete for a few reasons.
Excellent Dale, just excellent.
If it's not too late, fill the pier with pea gravel. NOT concrete. The vibrations will disappear completey even at high power.
On 5/9/10, Dale Wilson <dalel2112@yahoo.com> wrote:
As we were viewing M81 & 82, the guys started kicking the pier to see how well my design dampened vibrations. With the 40mm super-wide angle in my 10" lx200gps, the kicks were almost absent. It wasn't until I boosted up to 125x that the vibrations could be really seen. Even then, they subsided almost instantly.
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