[TowerTalk] NEW Tail Twister Rotator

[K8RI]

On 11/3/2012 10:51 AM, Kenneth Grimm wrote:
> While not taking issue with any of the comments made about the Tailtwister,
> I feel that I need to point out that while "overkill" in the form of the
> high priced worm gear rotors is fine, it isn't always necessary.  For
> example, I used a Tailtwister to turn a stack of a HyGain 204BA, Wilson
> 4-15 and Wilson 4-10 for about 15 years without failure.

I used to run a 5L KLM 20, 6L KLM 15, and a 7L Wilson on 10. Each on its 
own tower and turned by the Tailtwister's early ancestors. The Tail 
twister wasn't even available back then and I had nary a problem.  This 
was out in open flatland with absolutely no protection from the winds.

I never had a problem with a brake, motor, gears, or bearings.

When I moved here I put up the big array.  It tore apart the rotator in 
a matter of days. I picked up to HDR 300's.  The HDR rotators were 
plenty strong enough, but the motors offered too little resistance to 
turning.  One day which was kinda windy I tried to turn the system, but 
as soon as I released the brake the array spun around before I could 
stop it with the motor. It took the rotator right past the stops.

A few days later it did the same thing with a second HDR.  That was when 
I ordered the double worm gear rotator and swore I'd never use a rotator 
with a wedge brake on anything larger than a small tribander.

As these rotators were 20 feet down from the top of a 100 foot 45G they 
were a royal PITA to repair which required raising the mast a few inches 
with all that load and locking it in place to keep it from turning with 
the rotator out.

As I was working alone most of the time it took numerous trips up the 
tower and I'm now too old for that much climbing. Once or twice is OK, 
but I no longer have the stamina to spend all afternoon up there.

It's basically "the luck of the draw". I had those large antennas on 
small rotators for quite a few years, moved to a new location and lost 
them in short order.  If I do the math the torque from that bit array is 
no more than the big KLMs I had up. Yes, the lateral force is much more, 
but that was supposedly taken care of by two TB-3 thrust bearings. The 
wind load was well within the capabilities of the HDRs.


>
> After moving to a new location and a complete tower and antenna
> replacement, I decided to upgrade to a more powerful Yaesu G2800DXA.  After
> 2 years, the failure (mechanical/electrical) of the Yaesu led me to put my
> trusty old Tailtwister back up to turn a 4 element SteppIR and a Force 12
> Delta 230/240.  It has now survived a derecho earlier this year that
> produced 80 mph gusts plus the much milder winds (40-60 mph) from Sandy.
>   Obviously, I didn't try turning the antennas in 80 mph winds, but the
> brake held and the ring gear and case survived intact.
>

That's where we differ. If I want to operate, I don't care what the 
weather is, other than thunderstorms. <:-))


> I'm still scratching my head about what to use to replace the Tailtwister
> to give me that added feeling of security that you get with a little
> "overkill".  My original idea was the M2 2800, but the bad reports on
> eHam.net give me pause.  That is still my first choice....I think.  8*)  Is
> there another, better, made in America, rotor?

I may build my own next time with a gear reduction with external motor 
and use a commercial controller.

Now here's a rotator and antenna system.
http://www.rogerhalstead.com/ham_files/skyhook.htm

73

Roger (K8RI)