[Moon-Net] metric bolts for RAK
Mitch VE6OH CIW308
mitch at andor.net
Mon Apr 5 01:58:57 CEST 2021
All the units we have have nuts in them so it does not make sense. Humm
J. T. (Mitch) Mitchell
Amateur Radio Call VE6OH / CFARS Call CIW308 / CIW930
780 446 8958 Cell
Past Director for RAC - AB, NU, NWT RAC.CA
Celebrating 100 years of amateur radio in Alberta
Summer 2021 -- www.ar100.ca
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On 2021-04-04 17:00, Don Moman VE6JY wrote:
> That's surprising that the RAK (now) doesn't have nuts welded to the
> pipe. All mine have welded nuts, but they are older. The threads in
> the pipe itself would not be strong enough. I will make an inquiry.....
> On Sun, Apr 4, 2021 at 4:27 PM Edward R Cole via Moon-net
> <moon-net at mailman.pe1itr.com <mailto:moon-net at mailman.pe1itr.com>> wrote:
> Had several replies so will answer all here:
> Sorry Alfa-Spid RAK nor Alpha-Spid (got it)
> The RAK has just a round housing (call it a pipe). No nuts welded
> to it. Thread is only the depth of the pipe (maybe 1/8 inch or
> metric equivalent).
> Therefore was concerned that over tightening would strip out the
> Mast is what we call black-pipe; mild steel. 1.25inch I.D.
> schedule-80. Used same on my other antennas with no bends or
> I have learned thru experience not to trust pipe bolts from
> slipping so have been using a 5/16-inch bolt thru rotator pipe and
> mast to help hold the pipe but small enough to shear if something
> binds up. Well the rotator was installed in Sept. 2020 (six months
> I did maintenance on antennas and cables last weekend and found at
> least five loose set bolts. Also the head of the 5/16 inch bolt
> had been sheared off and weight of the array caused mast to drop
> slightly (nut end of shear bolt was intact and bolt had bent
> downward making removal impossible). So I re-tightened the set
> bolts figuring that would be OK for a couple months as I had plans
> to do more work in warmer wx (still winter here).
> This was a Sunday and only Home Depot open. The good bolt outlet
> is closed weekends. Rented Man-lift returned on Monday morning.
> So unlikely to find eight longer metric bolts on Sunday.
> Guess I could have used lock-tight (never occurred to me as other
> rotators never had this issue). I use an identical RAK on my
> 2m-eme system and it free-fell 50-feet in a high wind storm yet
> rotator was secure and undamaged; set bolts tight.
> Well I will use lock nuts and longer M10 bolts, plus lock-tight.
> I will replace shear bolt with at least 3/8 inch diameter.
> 6m-eme array is very large: 25-foot long cross boom with 32-foot
> long yagi booms. That catches a lot of wind force.
> Rotator may still turn the array in calm wx (??), but will require
> re calibration, frequently. Maybe, I can delay until May wx when
> easier to work without winter coats/gloves. I have to replace my
> elevation actuator and repair my digital encoder (which will
> require dismantling). Actuator arm is 40-inch long and weighs
> probably 35-lbs or more; awkward to handle at 45-feet. So I had
> planned to rent the man-lift for this work.
> 73, Ed
> At 01:15 PM 4/4/2021, Don Hawbaker wrote:
>> My SPID has nuts welded onto the pipe. It’s an RAS. Different
>> model. You have to be careful. I have stripped the threads on
>> at least one of the nuts. Someday I will cut it off and weld on
>> a new nut.
>> 73 WA3RGQ
>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986>
>> for Windows 10
>> *From: *Edward R Cole via Moon-net
>> <mailto:moon-net at mailman.pe1itr.com>
>> *Sent: *Sunday, April 4, 2021 4:50 PM
>> *To: *Andrzej Hoffmann <mailto:sp2fry at gmail.com>
>> *Cc: *ak-vhf at mailman.qth.net <mailto:ak-vhf at mailman.qth.net>;
>> moon-net at mailman.pe1itr.com <mailto:moon-net at mailman.pe1itr.com>
>> *Subject: *Re: [Moon-Net] metric bolts for RAK
>> Well we got as windy day, today. Only been a week since I
>> the Alpha-SPID set screws loose and tightened all eight of them.
>> My 6m-eme array is free-rotating in the wind. Apparently the set
>> bolts loosened up in only a few hours of wind, and the remains of
>> shear bolt has fully sheared off. And all because the mfr was too
>> cheap to supply stop-nuts (or lock-nuts) to keep the set bolts
>> tight. I actually tried adding a stop nut but that left too little
>> thread to tighten the set bolts (nut needs to be thinner or bolt
>> So either try to find longer metric bolts in America or quit and
>> smash everything to H and take up stamp collecting.
>> Was considering trying eme with the new array pretty soon, but it
>> will cost me another $233 to rent a man-lift just to tighten the
>> bolts (again).
>> Well, I will use a 1/2-inch shear bolt this time (equivalent diam
>> to 10mm).
>> I did test the RAK and its rotating ((evidenced by the change in
>> direction on the indicator) so apparently not a gear failure -just
>> not attached to the antenna.
>> Hopefully array will not over-rotate and destroy coax lines in
>> the process.
>> 73, Ed
>> At 02:37 PM 3/31/2021, Andrzej Hoffmann wrote:
>> >Hi Ed.
>> >If you have a problem with the metric screws I can send you some.
>> >Write down the length of the bolt you need. The original ones are
>> >probably 25 mm. As far as I know, they are M10 threaded screws.
>> >Vy 73
>> >Andrzej SP2FRY
>> 73, Ed - KL7UW
>> http://www.kl7uw.com <http://www.kl7uw.com>
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> 73, Ed - KL7UW
> <http://www.kl7uw.com/>Dubus-NA Business mail:
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