[TowerTalk] Yaesu G800 Slipping on 25G Rotor Plate

[k7lxc at aol.com]

>  ? A couple questions. I installed a G800 in a 25G tower with a thrust bearing top plate, that turns a JK Navassa 5 beam for a friend. At the beginning and end of rotation, the torque from the beam was causing the G800 to twist slightly on the plate, most likely from the bolt holes being? larger in diameter than the bolts. Apparently the grinding sound was a bit unnerving to the operator. So with a short wrench so as not to be able to easily strip the bottom casting, I incrementally and carefully started tightening the bolts to get to the point where it would not slip. So, you are probably smiling as you know what happened next. Yes, I stopped after stripping the first bolt hole in the casting. Fortunately, a new bottom casting is not that expensive from Yeasu and is on its way. So my questions are:1. How difficult is it to replace the bottom casting on a G800?2. Any thought on how to install the rebuilt G800 and not have it slip on the plate? Maybe something as simple as putting a star washer on each bolt between the plate and the bottom casting?      Yes, you should have some sort of locking washer between the bolt head and the plate or anything you don't want to slip.       But this whole episode has me confused. If the bottom bolts are properly tight, how is it possible for the rotator to move? Is it because of the broken casting?       I have never heard of a bolt breaking the bottom casting unless of course you were overzealous and overtightened it. Is that what happened?   Cheers,Steve     K7LXCTOWER TECH