A second thrust bearing normally allows a safe means to remove the
rotator (lift the mast and secure using the two thrust
bearings). That alone is more than enough justification for two
thrust bearings. I cut up an extra cross beam, drilled holes in this
"angle iron" for this second/lower thrust bearing and attached the
angle irons to the legs of the tower with u-clamps. Since the mast
and upper thrust bearing were already in place, the issue of
alignment was not a concern. I had pre-placed the second thrust
bearing on the mast as it was lowered into the rotator (making sure
the mast wasn't loading the rotator). One of my big gun friends,
K4TD was very concerned over my plans to only use one thrust bearing
since a 3-element 40 meter beam is not a small load. I don't normally
argue with the experts. Ken K5RG
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