[TowerTalk] Thrust Bearing for Use with Prop Pitch Rotor

[Paul Christensen]

>So, many of this type of bearing will not work due to the tight tolerances. A mast that’s been galvanized usually will not fit.  73 de Steve, NR4M

Good point, Steve.  Two years ago, N4CC and I were 48 hours away from "crane day" when we tested the fit of a 3-inch galvanized chromoly mast into a 3" flange bearing.  The mast was approximately 1/16" wider than the ID of the bearing.  We placed an emergency order through DXE for a set of Rohn TB-4 bearings which has the necessary clearance.  

The TB-4 raceway design is terrible but they've been working fine for the last 24 months.  Had the DXE bearings been available, we would have chosen that design over the TB-4.

Paul, W9AC