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Re: [TowerTalk] Sluggish crank-up tower

To: Rick Stealey <rstealey@hotmail.com>
Subject: Re: [TowerTalk] Sluggish crank-up tower
From: "Joe Giacobello, K2XX" <k2xx@swva.net>
Reply-to: k2xx@swva.net
Date: Fri, 20 Jun 2014 13:03:43 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Rick, I had a similar problem with an LM-470. It turned out that the solution was a rusted shaft between the motor and the large pulley. A squirt of oil onto the shaft and toward the portion of the shaft inside the motor did the trick. YMMV.

73, Joe
K2XX

Rick Stealey <mailto:rstealey@hotmail.com>
Friday, June 20, 2014 12:10 PM
K2XT, Rick here. I've recently been having trouble getting my tower to extend easily. It is a US Tower TX472 with the motor drive. Symptom when I first experienced the problem last fall was very sluggish starting. I'd give it a few seconds in each direction and then it would get going.

So now that I am in the midst of extensive maintenance (new winch cables, and some antenna work) I notice that the motor stalls out completely, and blows it's circuit breaker or thermal cutout, whatever it is, after 2-3 seconds. And of course there is no upward movement of the sections. I replaced the starter capacitor. Same thing. I removed the motor and it runs fine with no load.

Ok, so my next theory is a pulley is jammed, and that's where I seek some advice. I tried turning the "steering wheel" pulley by hand while the motor is off. That is the approximately 8 inch pulley that is driven by the belt from the motor. In the direction that should raise the tower sections it gets so tight that there is no way whatsoever a human could turn it more, and my gut feeling tells me there is also no way I should expect the motor to turn it. So, do I have a bad pulley on the tower sections, and how to know if a pulley is bad?

So, this morning, with the tower horizontal, I loosened the winch cable and removed a bottom pulley. A 3.5 inch dia one. I can hold the bushing and try to spin it. It turns and I can feel the bearings inside but trying to get it to spin and it only goes maybe a quarter turn. The feel of the bearings is sort of uneven. Could that bit of friction be causing the trouble? Of course I may find another pulley (hopefully) that is completely frozen, and that would solve my problems. Any opinions? Any first hand experience with such a situation? I put some motor oil on the bearings, no change. What about soaking the pulley in solvent, then oiling?

Thanks for any input.

Rick K2XT

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