I have an old Telrex rotator in storage that uses a 1/3 hp motor connected
to a gearbox with a chain. It doesn't look like it would be difficult or
expensive to duplicate with standard parts from Grainger. It is large and
most towers would require some modification to fit it inside. One could
also install a sprocket on the mast and use a chain connected to a gearbox
outside the tower. I know some of the EME guys make their own rotators and
so did K4JA, but it's really not that common.
BTW, Prop pitch motors cost thousands of dollars 60 years ago.
John KK9A
To: Towertalk
Subject: Re: [TowerTalk] Heavy Duty Rotor
From: Jim Lux <jimlux@earthlink.net>
Date: Tue, 06 Sep 2011 14:59:47 -0700
On 9/6/11 2:08 PM, David Jordan wrote:
> PPM's are great if you have $4,000 for one...
>
Exactly... seems you could find an off the shelf collection of parts
that get you there, perhaps with a bit of bracket fabrication (mind you,
where I used to work, the words "all you gotta do is fabricate..." were
guaranteed to result in giggles if not outright guffaws)
But these days, $300 gets you a brand new 2HP TEFC motor, another couple
hundred gets you a variable speed drive for it. The gearbox is going to
be a bit tricky, because you need several stages if you're doing
standard planetary gears to get down to the 1 RPM sort of speed you want
from 1750. But even so, I don't see it being more than $1000-1500 all told.
I suppose the market is SO tiny that it's not worth it for someone to do
anything more than a custom one-off. The existing products from M2 or
AlfaSpid or whoever are sufficient for 99%, and for the 1%, you're going
to be cobbling up something custom anyway.
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