[TowerTalk] Yet another worm gear box failure...

[KJ6Y at aol.com]

Mike's tower sounds like the shaft broke and not a gearbox failure.   On 
the older MD-750 motor drives, the shaft was 1 inch coming out of the  
gearbox. (Tristao and then US Tower).  US Tower then went to a larger  shaft, 1 1/4 
or 1 1/2, don't remember which.  Have not seen any of the  newer ones fail. 
 There is a lot of tension on that multi groove pulley,  especially when 
hams have a tendency to overload their tower. It's not just wind  load but 
weight.  Those towers have a weight limit.  Add it all up,  mast, rotor, 
antennas, cables, etc and I'm sure you'll see more weight then you  thought. 
Regular maintenance and inspections should be done.
 
Skip, _KJ6Y_ (http://www.kj6y.com/)  
_Communications Service Co_ (http://www.communicationsserviceco.com/)   
818-887-3569