Towertalk
[Top] [All Lists]

[TowerTalk] K-factor Revisited

To: <towertalk@contesting.com>
Subject: [TowerTalk] K-factor Revisited
From: froemke@ibm.net (froemke@ibm.net)
Date: Mon, 01 Mar 1999 10:05:20 -0600
Interesting discussion. Would anyone care to comment on what one could expect
from the new Yaseu rotor torque/vibration/shock dampening accessory for their
medium and high end rotors? (I understand that it goes between the mounting
bracket and the bottom of the rotor.)

Which rotor ratings would you expect it would improve and by how much?

Jim, K0MHC


Pete Smith wrote:

> At 10:13 AM 3/1/1999 -0500, Tom Rauch wrote:
> >
> >Hi All,
> >
> >I'm not a mechanical engineer, without a tag I don't know which
> >way to install a T-shirt, but one thing is obvious.
> >
> >Square footage alone is NOT a valid rating.
> ...
>
> >
> >Square footage tells us nothing about bending moment moments or
> >rotational torque, neither does weight alone....
>
> Amen. Don't failures often occur when the antenna is turning and has just
> reached the angle (relative to the wind) where wind pressure and momentum
> produce maximum rotating torque, at which point the brake is engaged (on a
> non worm-drive rotator).  If the torque at that moment exceeds the brake's
> ability to hold, then bad things happen to the brake and geartrain.
>
> >From my Yaesu rotator specs, I also notice that the rotating torque is much
> less - several times less - than the rated braking torque.  To a point, I'd
> assume the rotator would simply stall if you try to turn it into too much
> wind, but there must be some point where something more destructive
> happens, even without the brake engaged.
>
> This is why I'd be interested in seeing a number for maximum wind+momentum
> torque (at a specified wind speed) given as part of rotary antenna specs.
>
> 73,  Pete N4ZR
> Loud is good
>
> --
> FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
> Submissions:              towertalk@contesting.com
> Administrative requests:  towertalk-REQUEST@contesting.com
> Problems:                 owner-towertalk@contesting.com
> Search:                   http://www.contesting.com/km9p/search.htm




--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>