[TowerTalk] TIC ring slipping

[Tony Brock-Fisher]

I bought a well-used TIC ring from another ham. It had been up at least 
a decade and had several problems. During the course of rebuilding it I 
learned a few things about how they work and what can go wrong.

My TIC ring was very rusted. It had the wear you describe on the small 
rollers. It also had a bent shaft on the output of the motor, which has 
the small gear. In the course of repairing the unit, I think I came up 
with a hypothesis on how the shaft got bent.

With a lot of patient and careful work I was actually able to straighten 
the shaft by bending it back into true. I would not recommend this, but 
it was necessary because a replacement motor was not available from TIC.

Next I reassembled the ring in my basement. I found that because of wear 
on the small rollers, the rotating part was making contact with the 
fixed supports. You could see wear on the fixed supports. I was able to 
obtain replacement small rollers from TIC, so I replaced them all. This 
restored clearance between the rotating part and the supports.

Finally, I found that even with the spring loaded roller properly 
adjusted, due to wear on the large lateral rollers and the outside of 
the ring, there was excess play/clearance between the small drive gear 
and the ring. The lateral rollers were clearly worn down in the area of 
contact with the ring. I think that wear on the lateral rollers and the 
outside of the ring increased the clearance beyond spec. The cure for 
this was to elongate the mounting hole on one of the lateral rollers so 
it could be mounted closer to the center, thereby taking up the 
increased clearance due to rust & wear.

I hypothesize that the increased clearance allowed the ring to slip as 
you describe. I also suspect that when this happened, the small gear got 
'out of sync' with the large gear, resulting in contact between the high 
points of both, which jammed the rotor and caused the shaft to bend.

Bottom line: I would strongly advise fixing the clearance problem before 
using it further, as you may suffer a bent shaft, which will be a bad 
thing, as the motors are not currently available (unless its a newer 
version than mine).

Tony, K1KP