[TowerTalk] Bolt patterns/sizes?

J.P. Kleinhaus w2xx@cloud9.net
Sun, 09 May 1999 10:10:20 -0400


I am having some rotor and thrust bearing shelves made for a tower.

The intended rotor is the Orion 2800 and the thrust-bearings are
to be Rohn TB-3's.  I found a .PDF file with the drawings of the
Orion bolt pattern and it states a standard 3"x3" bolt pattern.
However, it does not give the sizes for the hardware, so I have
no idea what to tell the machinist as far as the diameter of the
holes.  Also, does anyone know the size of the center cut-out 
that is required to pass the cable up to the rotor through
the plate?  It's also not defined on the document.

Having searched the Rohn website and my Rohn catalog, I have
not been able to find a single reference to the pattern of
bolt holes needed for the TB-3 bearing, nor, obviously, the size
of the hardware needed.  I am willing to assume the TB-3 also
fits a "standard" 3x3 bolt hole pattern, but still need additional

If anyone has this information, I would be most grateful.

73, J.P. W2XX

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