[TowerTalk] Proper torque settings for G-2800 rotator mast clamp bolts?

[Art Greenberg]

I am. 2-inch chrome-molly mast with a 4el SteppIR. Probably overkill, 
but I did see some slip with the OEM mast clamp and I didn't want to 
have to pin the mast.

I have;n tried your proposed installation method, but it seems like it 
would work if you can slide the rotor straight in.

-- 
Art Greenberg
WA2LLN
art at artg.tv


On 12/25/22 10:12, Jim McDonald wrote:
> Is anyone using the K7NV mast clamp with the Yaesu G2800?  Any issues?  Can it replace the Yaesu brackets without raising the mast to accommodate it?  (I understand I'd have to remove the rotor to slide the K7NV clamp up onto the mast.)
> 
> Thanks!
> 
> Jim N7US
> 
> 
> -----Original Message-----
> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of Grant Saviers
> Sent: Saturday, December 24, 2022 18:34
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Proper torque settings for G-2800 rotator mast clamp bolts?
> 
> I believe from using 3 Yaesu rotators, the 2800 bolt torque limit is more about the yield strength of the die cast clamps than the bolt strength.  A torque wrench will measure what "1/2 to 1 turn" really means.
> 
> The bolt heads will be marked so that will reveal the bolt strength and the permitted maximum torque can be looked up.  Since everything yields a bit, it is best to tighten in a pattern and repeat it 3 times.  After a day or two is even better but that is another tower climb.
> 
> Grant KZ1W
> 
> On 12/24/2022 11:50, Alan Higbie wrote:
>> As the result of an extremely high wind event, I will soon be going up the tower to loosen the G-2800 mast clamps, realign the mast and then re-tighten the M8 x 70 bolts.
>>
>> The Yaesu G-2800 manual says:
>>
>> “Caution: Do not over-tighten the nuts on the mast clamps.
>> They should be tightened until the spring washer becomes flat, then tightened further by 1/2 to one turn maximum.”
>>
>> I am still using the original hardware supplied with the G-2800.
>>
>> These spring washers have been in service for 5 years - so their springy-ness may not be the best indicator for torque.
>>
>> I believe that torque settings depend upon the grade of hardware being used: e.g. 8.8, 9.8, 10.9 or 12.9 - but I don’t know the grade of the stock hardware.
>>
>> What its the proper torque setting for these M8 x 70 bolts?
>>
>> 73,
>>
>> ~ Alan Higbie K0AV
>>
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