I had a discussion with M2 and came out thinking that YES, they do want the
mast to slip acting as protection to the gearing.
As to getting torque numbers for tightening the mast clamp bolts, M2
hesitated but then said 40 ft lbs.
I have asked Towertalkians before, but with no response, whether a somewhat
flexible torque tube in line with the mast would help. When I watch my
MonstIR with a moderate wind, I see the ends of the elements flopping back
and forth after apparently hitting the worm gear to stop them. If the shock
was reduced or spreadout over time by a coil spring or radiator hose-like
tube, would that help to let the mast clamps hold the mast against a
constant wind force?
----- Original Message -----
To: "Towertalk" <email@example.com>
Sent: Tuesday, January 09, 2007 4:51 PM
Subject: [TowerTalk] Orion RC2800P
> Using SLIPP-NOTT on and Orion 2800 rotator mast clamp might be akin to
> putting aluminum foil around a fuse. I would ask M Square before doing
> that. My 14 year old RC2800P slips, but I understand the newer rotator
> clamps are better. The literature also recommends against pinning the mast
> to the rotator as it will void the warrantee. That tells me they want the
> slippage to act as a sort of fuse. If you can't tolerate the slippage, and
> you have a big stack and environment that will cause it, then you should
> probably use a different rotator.
> I currently have 23.4 sq ft of antennas on mine which is well below the
> advertised 35 sq ft capacity. One of my antennas is the Force 12 EF180C
> 80M rotating dipole which is 83 feet long. I feel it is the main
> contributor to the slippage problem. You should see it dance around in a
> wind storm. It is only 4.5 sq ft wind surface area, but the element
> lengths are a very long lever arm working against the rotator at all times
> (start, stop, wind). I have had problems with the controller, but the
> older units had problems that have been fixed in newer units. If the
> EF180C were not on the mast, I think my slippage problems would be minimal
> or non-existent. Even with an old ac motor type 2800 like mine, I feel it
> is a very good rotator. The controller is another story though. Some folks
> have switched to Green Heron controllers which they claim are better.
> The best way to eliminate or minimize slippage is to follow the proper
> sequence for tightening the 10 clamp bolts. With the 4 clamp base bolts
> loosened, tighten the heck out of the 6 mast clamp bolts. These are Grade
> 5, 3/8x24 steel bolts and can take a fair amount of torque. M Square folks
> should be able to give you a torque value if you need it. After the 6
> bolts are good and tight, tighten the 4 clamp to rotator base bolts. If it
> slips after that, it probably needed to for protecting your rotator gears.
> The M Square folks bought a bit of a mess from Orion and have been trying
> to improve on the product quality and reliability. They are always very
> helpful to me over the phone which is better that some others I can think
> John Owens - N7SEJ
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