[TowerTalk] PST61 Rotor Reliability?
jim.thom at telus.net
Wed Dec 13 13:28:54 EST 2017
Date: Tue, 12 Dec 2017 15:40:22 -0500
From: k7lxc at aol.com
To: towertalk at contesting.com
Subject: Re: [TowerTalk] PST61 Rotor Reliability?
> ?Thanks for the reply, Steve, but I'm sorry ... that doesn't make sense.? Torque is torque, and it's in the same direction no matter which side of the mast is applying the torque.
Hiya, Dave --
? ? I'm ?not an engineer so I can't defend the conclusion that Dick Weber, PE (don't remember his call) published and suggest you read his article in QEX. Someone cited the issue and date of publication so it shouldn't be too hard to find.
? ? It was a revelation to me and it might be to you as well after you read Dick's article. I promise won't say I told you so - hi.
Steve ? ? K7LXC
## Steve et all, the fellow has a very unique situation. His tower and pair of yagis are being hit by a mini tornado, thats 50-200 ft across, with 90 mph winds.
In his one off case, adding a TQ comp plate will do nothing, except to increase the load at the shorter end of the boom, and make things worse. He doesnt
have wind from just the usual single direction, hes being hit by high winds from several directions.....and simultaneous. Thats the worse nightmare one could imagine.
The resulting TQ on his poor PST61 must be insane. Its one big corkscrew of a windload.
## The only fix I can see that would work is possibly either the larger PST-71 or PST 110, 115 or either small or medium sized PP from K7NV.
If it was me, I think I would opt to remove the PST-61, get it repaired, sell it, then replace it with a PP. If you are going to spend $$ spend enough of it
on a correct solution. The PPs all use planetary gears. The final gear is driven in 3 places, every 120 degs. Every other rotor is driven in only one place.
And dont even think about using a m2 OR-2800 or HDR-300, neither will last a week.
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