[TowerTalk] 2nd thrust bearing inside tower - you opinions??

[hdmc38 at bellsouth.net]

John you need a 2nd thrust bearing and the correct mast,be it 4130 chrome molly or what ever.I run 45G with the 1st bearing on the top section.The second bearing is midway down the top section. Then the rotor close to the bottom of the top section.The antenna is a Force 12 C3S/HH turned by a Yaesu G-1000DXA.Yaesu has the specs on how much weight can set directly on the rotor.I believe they call it the K factor.All the weight sits on the rotor the thrust bearings alighn the mast thru the tower.The mast is pinned at the rotor per Yaesu specs(rule #1 always do what the manufacturer says).It can be time consuming to alighn all this,But the more work you do on the ground the less you do in the air.Force 12 has a unique mounting system.that allows you to install 1 plate on the mast,the second on the boom.when the antenna goes up you just bolt the 2 plates together.Its designed so you can't do it wrong.I took the top section on the ground,Installed all the parts and plates,aligned i
 t and even tested the rotor on the ground and set the direction also.A rohn thrust bearing has a different bolt pattern than the rotor.Custom Metal works makes a bearing shelf just for this purpose.Cost is about the same as a second rotor shelf and you won't have to modify it .Array solutions has the bearing shelf.Do alot of planning ie square ft load , total weight.You did not mention where your QTH is but ice and snow may need to be in the plans.The only other thing I would recommend is use a crane if possible.You pick up 3 sections of 45G already assembled.You will be a lot happier  doing it this way than with a gin pole and a tram.The extra cost is well worth it.My antennna has been up this way for 5 years now and with just a little maintainence it will be there 10 more. Just my op but it sure worked slickHope this helps.Oh by the way this set up wen't thru 4 hurricanes the worst being Wilma and withstood 110 MPH winds with out a problem.Florida is Paradise!

                            73 Joe K4XZ
> 
> From: "K5XA John" <k5xa at godfather-ridge.com>
> Date: 2007/02/21 Wed AM 09:37:59 EST
> To: <towertalk at contesting.com>
> Subject: [TowerTalk] 2nd thrust bearing inside tower - you opinions??
> 
> Howdy,
> 
> Need a little advice. 
> 
> Planning about 130 feet of Rohn 45 - 20 to 22 feet of mast - Force 12 Magnum
> 240N over a Force 12 C31-XR at the top - side mounting another C31-XR.
> 
> Considering a 2nd thrust bearing inside the tower.
> 
> Any suggestions/ideas/experiences you might share?
> 
> Tnx!
> 
> 73 ............... K5XA
> 
> John Guida
> k5xa at godfather-ridge.com
> 
> 
> 
> 
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JOE PATRICK
SENIOR PLUMBING/MECHANICAL
INSPECTOR CITY OF BOYNTON BEACH