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2025.10.12 K0DV clamp replace:


Doug had called earlier with concerns that the control box was now showing it was facing roughly South,
when it had been left facing North. He had tried re-calibrating it but the calibration looks fine. But the
antenna does appear to have moved. Did the brake fail? I hope we don't have yet another problem to fix,
I'd like to see this finally all sorted out. (remember, it all started back in in July with a balun repair)

Lets try this one more time. Arrived back with some replacement hardware. I'm pretty sure that was a 1/4"
u-bolt, with 7/16" nuts. When I got there at first I thought the antenna had just moved a small amount, but
then I realized it was facing the other direction, just a bit East of South, which agreed wth the control box
which was also showing maybe 15 degrees short of full scale (South) This was REALLY looking like a
brake failure, but that would also probably involve damage in the rotor. (pinion or ring gear)

After some discussion with Doug, he was certain he hadn't touched it and it should be still facing North. I
knew he had added computer control to his control box, (for Rig Control) but he was also certain he hadn't
tried to turn it that way either. After some time though he realized he had protection software running that
would automatically turn the beam into high winds when idle, and it had turned itself South to face into the
wind. That was a big relief for both of us, no longer worrying about rotor damage.

I sifted through my spare parts box and pulled out a few stainless clamps in good condition, though they
were slightly different widths. So I was very thankful to have taken that picture the other day with the
wrench in it, and was able to identify the one clamp I had that would fit the rotor. After a climb, swapping
the clamp was completed pretty quickly, (and uneventfully) After swapping the clamp, Doug gave it a full
360 test, and I came back down.

The other day I wasn't able to examine the broken end with the nut on it since it had shot away from the
rotor when the bolt broke. (thankfully not hitting anything on the ground) But I did have the broken clamp
to take a closer look at now. It shows a very clean break, with no signs of any defect in the metal (like a
bubble) and the break is fresh all the way through. (so no crack) All I can assume at this point is cheap
stainless. The bolt is an unmarked 1/4" stainless. I examined the other side of the clamp and noticed a
nut doesn't quite spin freely at the point it would settle at. A closer inspection finds a 1/2 turn of thread
at that location is discolored. It doesn't photograph well and is almost invisible under magnification but
is clearly visible from a distance. I think the nut on the other side was also just about to fail at the same
spot. All I can assume at this point is a bad batch of Chinesium stainless.

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