[TowerTalk] Tailtwister failure mechanism
Steve London
n2icarrl at gmail.com
Wed Sep 19 08:46:05 EDT 2007
I have had 2 Tailtwister failures in the past 3 months with the same T2X, same
antenna, same tower. What is puzzling is that the failure mechanism has been the
same both times, and I haven't previously seen this kind of failure.
In both cases, the gear shaft has broken. The gears themselves are fine - no
broken teeth, etc. What I don't understand is how there are any significant
forces on the gear shaft. The gear shaft is supported by the brake housing on
one side and the motor bracket on the other side. I just don't see where the
shear force is coming from.
And, yes, I'm turning a fairly big antenna with it - 5 el 20, 40' boom. The
rotor is about 2 feet down from the top of the tower. The full weight of the
antenna is on the rotator (about 90 pounds), with a homebrew thrust bearing to
limit the lateral forces.
Please, no bashing of CDE, HyGain, MFJ, or my stupidity in trying to use such a
small rotator to turn such a large beam. Constructive comments only !
73,
Steve, N2IC
More information about the TowerTalk
mailing list