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.
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.
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?
Ken - K4XL
On Sat, Nov 3, 2012 at 4:31 AM, K8RI <K8RI-on-TowerTalk@tm.net> wrote:
> On 11/3/2012 3:37 AM, Jim Thomson wrote:
>> Date: Fri, 2 Nov 2012 14:41:07 -0400
>> From: <firstname.lastname@example.org>
>> To: <email@example.com>
>> Cc: firstname.lastname@example.org
>> Subject: [Amps] NEW Tail Twister Rotator
>> If interested.
>> NEW Tail Twister Rotator still in original box. Includes Contains (All
>> new in box), New control head, New hardware, New connectors, manual New
>> Warranty Registration card. I purchased one two many units for what I
>> needed. http://www.ebay.com/itm/**330810645370?ssPageName=STRK:**
>> Contact me direct and ask me me to pay the shipping. email@example.com Save
>> three ways, $200.00 plus TAX plus SHIPPING on brand new unit. This won?t
>> last long. Tail Twister Rotator is Hy-Gain big rotator. Turning power 1,000
>> 73, Bruce, W8HW
>> ### BTW, the “turning power” is NOT 1000 lbs on that rotor. It’s
>> rated at 1000 INCH lbs of....”stall torque”. 1000 inch lbs / 12 =
>> 83.33 FOOT lbs of stall torque. I find it amusing how these rotor
>> makers like to bs the numbers
>> on these rinky dink rotors. They will use terms like.. “start up
>> torque..... running torque...and stall torque” . The start up current
>> on any of those small motors is typ triple the running current...... hence
>> the “start up torque” number can be a LOT higher than the
>> actual running torque. Stall torque is just that, you put enough of a
>> load on it, that it actually stalls out....as in ZERO rpm for both the
>> motor and obviously the ant itself.
>> ### In the bigger scheme of things, 83 ft lbs of torque is not much at
> On a 36" pipe wrench it is slightly less than 28# (83/3), or you could
> hold it easily with one hand. OTOH a 24" wrench 83/24= 41#. It might catch
> you unaware, or unprepared, but again it can be held easily.
> The motor is tiny and it takes very little input from the output shaft to
> drive the motor armature and with the gearing that little sucker really
> screams as you are looking at a gear ration of nearly 2000:1. I've never
> checked but the armature probably turns some where between a 1000 and 1700
> RPM. That's why they need that wedge brake.
> With one of the double worm gear rotator it's possible to have several
> thousand foot in# or in the case of the PST61DHP 7,641/12 or 641 ft #. or
> 1377 ft lb of break/holding torque. The case might not be up to it, but
> that is a lot of torque.
> Don't go experimenting though as you need things anchored securely and
> it's very easy to severely pinch things you'd prefer not to pinch.
> Roger (K8RI)
> The flip side is.... IF ant makers torque balanced their ants
> correctly, you would require very little TQ to rotate the array. I used
> K7NV’s software to design a TQ compensation
>> plate on a local fellow’s HB 5 el 20m yagi. Without the TQ comp
>> plate installed, it would literally destroy the tail twister...plus a 2nd
>> tail twister. He had taken a 204BA......and had added a 5th ele to
>> it....plus lengthened the boom. He had
>> mounted the yagi at it’s center of gravity, which then put a lot more
>> boom out one side vs the other. That alone created the gross TQ imbalance.
>> ## The fix is simple, either mount at the dead center of the boom and
>> use a counterweight at the light end of the boom. (K7NV’s software will
>> also calculate the required weight.) Or mount at the CG... and use the
>> TQ comp plate. You can also use a combo of both schemes. The
>> alternative is to use a rotor that has WAY more TQ. The tq comp plate
>> scheme was tested by installing the yagi on a short 30’ tower, with NO
>> rotor..and just let it windmill. In a 30-40 mph wind it did not
>> windmill...and in fact the owner could climb up the tower and turn the
>> yagi by hand. It stayed put in whatever direction it was pointed. The
>> comp plate was then removed, and the yagi will windmill badly. If
>> stacking yagi’s on one mast, alternate sides on the mast to account for the
>> offset between mast and boom.
>> ## IMO, for the $$ they want for the tailtwister, it really is not a
>> big bang for the buck.... and ditto with the Ham-3-4-5 series with its 800
>> in lbs of tq. ( 67 ft lbs). Rating any of these rotors in terms of ant
>> sq footage is ludicrous.
>> Jim VE7RF
>> TowerTalk mailing list
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Ken - K4XL
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