Observatory dome crank mechanism

[bloodhound31]

Broke the third crank mechanism! The dome is just too heavy! I wore out two round holes for a crank handle into oblong holes in just a few complete rotations. Two 1/2 inch holes through mild steel rhs turned into 1/2 inch by 1 inch oblongs.

So now i have built a SUPER CRANK MECHANISM out of two 25mm roller bearings side by side. I'll be getting Ron to put it on the site for me, on the support ring page.

http://www.aussiepeople.com.au/asignobservatory/Supportring.aspx

Until then, heres a couple of pics.


Baz.
_________________
A.S.I.G.N. Observatory

http://www.aussiepeople.com.au/asignobservatory/

[Blob]

Hum,
out of interest what the observatories latitude, longitude and altitude above sea level etc?

[trinitree88]

Bloodhound. As you have electric at your site you could consider the air hockey table assist, if you ever retrofit. A skirt is fitted to edge of the steel ring. Compressed air is blown as a boundary layer between the dome base, and the ring. It lifts the wall, and the cranking is easier. MIT uses such a setup to move the radiation shield at their LINAC. A ~100 ton cement door ~ 10 meters tall, ~ 1/2 meter thick, and 5 meters wide, moves at the arm push of a single man when the air flows. No motor. World's ugliest hovercraft.