Towertalk
[Top] [All Lists]

Re: [TowerTalk] Ring Rotors

To: Grant Saviers <grants2@pacbell.net>, "towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Ring Rotors
From: "Chuck R. Korzendorfer" <ckorz@multi-craft.net>
Date: Mon, 30 Jan 2023 23:14:59 +0000
List-post: <mailto:towertalk@contesting.com>
W9RE has a very nice design for his rotating side mount in the Sept/Oct., 1987 
issue of NCJ using structural aluminum plate & angle.  I am in the middle of 
building one for a small tribander.
KM5G

Get Outlook for iOS<https://aka.ms/o0ukef>
________________________________
From: TowerTalk <towertalk-bounces@contesting.com> on behalf of Grant Saviers 
<grants2@pacbell.net>
Sent: Monday, January 30, 2023 5:08:15 PM
To: towertalk@contesting.com <towertalk@contesting.com>
Subject: Re: [TowerTalk] Ring Rotors

[External Email]

Might be better as a new topic "swing arm mounts"

Some expert advice I got was to use crossed A36 angle steel (2x2x1/4 or
1.5x1.5x3/16) U-bolted to all three legs and mount the rotator close to
the tower on a 3/16 plate bolted in the V in the outside gap.

Repeat for the top bearing, xx feet above the rotator.  Could use a
stock "thrust" bearing or a simple UHMW block with all the load on the
rotator.

The swing arms were about 33" long mounted the the mast, which was going
to be 1-7/8" x 0.188" 1026 DOM.  The mast was to be 13ft between mounts
so able to mount 2 yagis.  A triangular brace mast to arm and a stub
mast welded on the arm to mount the antenna with a stock mast-boom
clamp.  Of course YMMV.

It's important to have all three legs capture the loading.

Ideally get it all hot dip galvanized or do a good pant job.

And find a PE to recommend a design for the planned yagis.

Grant KZ1W

On 1/30/2023 11:32, Steve Maki wrote:
> On 1/30/2023 2:23 PM, Lux, Jim wrote:
>
>> On 1/30/23 11:10 AM, Steve Maki wrote:
>>> On 1/30/2023 1:48 PM, Lux, Jim wrote:
>>>
>>>> On 1/30/23 9:46 AM, Grant Saviers wrote:
>>>>> I agree side mount + swing arm is a good option.
>>>>>
>>>>> Although my 7 K0XG R65 rings have worked great minus one motor
>>>>> failure, I would do side mounts for future (unlikely) towers.
>>>>>
>>>>> The advantages of side mounts are lower cost & weight, using
>>>>> standard rotators, and if desired with multiple beams on a long
>>>>> mast between rotator and top support.
>>>>>
>>>>> The side mount disadvantages are less rotation (but still can get
>>>>> ~250*), some offset load on the tower (use 6 guys or star
>>>>> brackets), and easily fabricated or purchased unique parts,
>>>>> although you/PE need a design.
>>>>>
>>>>> I think the updated Orion 2800 is a better choice than the Yaesu
>>>>> for very big beams.
>>>
>>>> I've been thinking about this, and I wonder if there were some "not
>>>> too complex" scheme with an extra hinge point on the arm that would
>>>> get you 360 degrees.  Not that I would build such a thing (would
>>>> that I had room for it) - but I was thinking if you had an arm that
>>>> is the length of a "face" of the tower, and some sort of offset
>>>> crank linkage, you could get 360 of rotation from 240 degrees (or
>>>> less) of movement from the primary arm.   My mind's eye has this as
>>>> like a "wrist" that reaches around the tower. Yeah, you'd have the
>>>> mass of the antenna as a cantilever load, which would put a bending
>>>> moment on the tower.
>>>
>>> A swing arm where the rotor is mounted straight off a tower leg is
>>> good for 300° easy. That's plenty as long as you have another antenna
>>> to cover the dead zone.
>>
>> Oh yeah, I figured that.. I was just contemplating "clever mechanical
>> solutions" - The swing arm is actually a nice solution in general -
>> simple, uses off the shelf stuff, can be added after the tower is up,
>> etc.
>>
>> It's like the hinge plates for mounting an antenna on a tower/mast
>> that pivots from horizontal to vertical - a simple clever solution.
>>
>> Of course, the other solution is to mount two (or three) Yagis and a
>> combining network to phase them (or just switch). <grin>
>
> Yep, I was trying to picture your idea. Back when linear actuators were
> cheap (used in the satellite dish industry) I put some time into
> thinking about a way to use one or two to turn a large yagi on a swing
> gate. It never got past day dreaming and a little pencil scratching.
>
> -Steve K8LX
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.contesting.com%2Fmailman%2Flistinfo%2Ftowertalk&data=05%7C01%7Cckorz%40multi-craft.net%7Cdd5c7d13b7304b38f9cd08db0316e431%7Cea9476d4b45b4be3a5c00f48ea376b81%7C0%7C0%7C638107169086036960%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=03JAFMgIlznNarpIu54q6VV8rdFBvD35AiviG%2BEZMp0%3D&reserved=0
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.contesting.com%2Fmailman%2Flistinfo%2Ftowertalk&data=05%7C01%7Cckorz%40multi-craft.net%7Cdd5c7d13b7304b38f9cd08db0316e431%7Cea9476d4b45b4be3a5c00f48ea376b81%7C0%7C0%7C638107169086046913%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=lPQ9%2FVQXsNAdh0DYHmCFPcniKsLsvO4xmdPh4xNhXFQ%3D&reserved=0
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

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