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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