Chamberlain Elite is the name of a big mfr of these things
http://www.eliteaccess.com/elite/products/
The ones near my house (the burly commercial ones) have a geared motor
connected to a large hub about 8" in diameter and 2" high. There's a clamp
like arrangement that goes around the hub, with a 1/2" bolt and lever handle
to tighten the clamp. If you overload it, the clamp just slips on the hub
(unless you've over tightened the clamp, in which case you break gears or
shear pins). If you need to manually open the gate with no power, you
remove the cover over the hub arrangement, turn the clamping bolt about
90deg, which releases it enough so that it will slip around the hub.
A clever design, but probably massive overkill (they have 1HP motors in
them)
The same company makes leadscrew type actuators:
http://www.eliteaccess.com/elite/products_category/0,3723,category_id-2,00.h
tml?frst=1
This seems to have a 15 second or so stroke time, and draws about 12Amp
froma 24VDC supply (making it probably a 1/4 HP or so motor).
However, I'll bet these things aren't cheap!!!.. If your tilting antenna is
balanced (and there's no reason why it wouldn't be, right), then you don't
need huge force to move it up and down.
This is giving me all sorts of ideas about an antenna that normally sits
down on the roof, but swings up vertically when in use. Hmmm..
----- Original Message -----
From: "Hank Lonberg" <kr7x@comcast.net>
To: "'Jim Lux'" <jimlux@earthlink.net>
Sent: Saturday, January 29, 2005 9:34 AM
Subject: RE: [TowerTalk] Vertical Automatic Tilt Over
> Rich:
>
> I would look up in the yellow pages for those companies that sell
automated
> gates and closures systems. Especially the ones that sell the big wrought
> iron gates that swing horizontally ( the big estate ones). They may be
able
> to sell you the actuator system or give you the manufacturer name.
>
> Just a idea of where to start.
>
> 73
> Hank / KR7X
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Jim Lux
> Sent: Saturday, January 29, 2005 8:48 AM
> To: Richard Thorne
> Cc: Towertalk
> Subject: Re: [TowerTalk] Vertical Automatic Tilt Over
>
> Those aren't that heavy an antenna...
>
> I'd look into one of the leadscrew positioners used on C-band satellite
> dishes. They're readily available surplus, and have suitable thrust and
> speed(not too fast). I've seen both AC and DC powered ones. Limit
switches
> are nice..
>
> Places like McMaster-Carr have bare ACME thread leadscrews and follower
> nuts, if you've got a motor to drive them. Put the follower in the end of
a
> piece of pipe, and spin the screw.
>
> A garage door opener is also probably in the right ballpark motor size and
> speed wise (and, has limit switches, and even a remote control!).
>
> You could also try to cobble up something with cables and motorized
winches
> (if you have a source for an inexpensive reversible winch, this might not
be
> a bad idea)
>
> If you want to just buy a surplus lead screw positioner: C&H Sales in
> Pasadena CA has the following (don't know if it's suitable, or reasonably
> priced, but this is the idea.. The description doesn't say what the
travel
> is, but you could probably call them. It's probably a couple feet.)
>
> LINEAR ACTUATOR #820154. Motor is rated 24 VDC. The motor running without
a
> load on the actuator shaft pulls 1.0 amp. The unit has built-in MicroR
> switches with a gearbox driven cam system. The switches and cams are set
to
> stop the actuator travel at the extremes of its travel. This limit switch
> sys tem can be set to limit the actuator travel anywhere within the
actuator
> travel range. Additionally, a 27-slot encoder wheel and pulse producing
> slotted pick-up system are built into the main gearbox. This encoder wheel
> rotates at the same speed as the actuator screw shaft. This system allows
> close positioning of the actu ator shaft. The encoder pick-up unit
requires
> 12 VDC for operation. The unit runs until the limit stops are reached in
> either direction. The unit stops automatical ly when it reaches either
limit
> stop. The unit can then be reversed by reversing the polarity of the input
> volt age. The actuator motor is a permanent magnet DC type and will run on
> lower voltage if desired. The motor/gearbox/encoder/limit switch assembly
is
> mod ular in design and lifts out as a unit for service or adjustment. The
> internal parts are enclosed in a sturdy cast aluminum enclosure. The
> enclosure has a sturdy lid and sealing gasket. Ideal for outside uses such
> as steering satellite dishes. As supplied the actuator has a 6 ft. long
> multi-conductor PVC insulated cord for elec trical connections. The
actuator
> rod end has a swivel ing ball and socket end fitting. The bore of the ball
> socket is 1/2". The width across the face of the ball socket is 5/8"
Overall
> dimensions: 8-3/4" wide x 5" deep x 36-1/2" long (with actuator rod
> retracted). Stock #DCLA9801
>
>
> ----- Original Message -----
> From: "Richard Thorne" <rmthorne@cox.net>
> To: "Tower Talk (mail list)" <towertalk@contesting.com>
> Sent: Saturday, January 29, 2005 7:55 AM
> Subject: [TowerTalk] Vertical Automatic Tilt Over
>
>
> > I live in a restricted neighborhood but I would like to put up a
> > Cushcraft R8 or Hygain 640 10 through 40m vertical.
> >
> > I plan on installing it on a tilt over mast so it will be out of site
> > when not in use, I think the neighbors could live with that.
> >
> > So I got to thinking it would be nice if I could hit a switch in the
> > shack to tilt it over or tilt it up.
> > I was thinking I could sandwich a 2" alumium mast between a pair of
> > 4x4's with a bolt at the top for the hinge point.
> >
> > Has anyone seen such a device. I'm sure this will have to be home
> > brewed using an air cylinder or maybe a rotor and some limit switches.
> >
> > Any ideas?
> >
> >
> > Rich Thorne
> > ARS: N5ZC
> > AMA: N5ZC
> > Amarillo, TX
> >
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any
> questions and ask for Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any
> questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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