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View Full Version : Yaesu GS-050, GS-065 thrust bearings: anyone installed this way?



AE7F
02-16-2012, 06:01 PM
Consider the following picture:
86362
86363

The picture describes 3 different ways of installing a Yaesu GS-065 thrust bearing. I have mast - not a tower - and have been considering a rotator cage (best), but if that doesn't work out there is another option to take bending strain (not true for vertical load) off of the rotator. This is documented in the picture above. See the diagram "installing halfway up the mast" on the bottom-right. Have any of you installed a thrust bearing that way? It looks like if you were to guy above the rotator and then just below the rotator, you should end up with a pretty stable mast install.

The idea is to install a spiderbeam on the mast while not destroying the rotator (Alliance HD-73). This install would definitely remove some of the bending moment load from the rotator but it would probably increase the vertical load. The vertical load on the rotator bearings would increase as you tighten the guy lines.

Comments?

AE7F
02-16-2012, 08:06 PM
Specific installation:
86377

Does it look sufficiently strong enough?

NH7RO
02-16-2012, 09:06 PM
Looks great to me, especially for what you'll be mounting on top, Ben.

I've always used gray PVC disks glued together for floating guy collars but then my Moxons are not as big as a spiderbeam.

73, Jeff

WB2WIK
02-16-2012, 09:34 PM
I think it would be okay, too.

I wouldn't make that the only set of guys on the mast, however.

I assume you'll have the main 4" mast guyed down lower, also?

AE7F
02-16-2012, 09:56 PM
I think it would be okay, too.

I wouldn't make that the only set of guys on the mast, however.

I assume you'll have the main 4" mast guyed down lower, also?

Steve, I've had the same thoughts. I should probably guy at the flange under the rotator as well.

Now.... how can I make sure that the 4" mast and the standpipe are both aligned and vertical? The top mast portion would be very difficult to measure at 30ft....

NH7RO
02-16-2012, 10:11 PM
Ben; couldn't you plumb the standpipe in the rotator before it's atop the mast? I would think that it's not going to be so critical anyway as the thrust bearing is only a few inches above the HD73. If it was obvious to the eye that it's askew then I'd be concerned but I really don't think that would be the case.

73, Jeff

AE7F
02-16-2012, 10:33 PM
Ben; couldn't you plumb the standpipe in the rotator before it's atop the mast? I would think that it's not going to be so critical anyway as the thrust bearing is only a few inches above the HD73. If it was obvious to the eye that it's askew then I'd be concerned but I really don't think that would be the case.

73, Jeff

Well, my drawing isn't really to scale though... I would have a choice where to install the thrust bearing. The closer it is to the rotator, the shorter the standpipe can be. I would definitely install the standpipe before it's atop the mast. It will be challenging trying to adjust the guys as the mast is raised so that the standpipe does not bend.

If I can make this work, this will be the key to continuing with my wire beam project. If not, I will run out of time waiting for scrap metal to build a rotator cage.

Sure wish I could find a 4" floating guy slip ring so I could just turn the whole mast...

AE7F
02-17-2012, 03:33 PM
I think it would be okay, too.

I wouldn't make that the only set of guys on the mast, however.

I assume you'll have the main 4" mast guyed down lower, also?

Anybody know if a GS-050 bearing would work?

The only thing I could find as far as differences between the 050 and the 065 is that the 065 is specified for a 0.5" larger diameter mast. Here is the difference in the way they look (scroll down): http://www.universal-radio.com/catalog/hamrot/ysurot.html

It looks like they might use the same size of bearing but the 065 has additional mast screws.

AE7F
02-17-2012, 09:54 PM
I ordered a GS-065 thrust bearing today.

Even if I want to rotate the entire mast from the bottom, I will still need a slip guy ring at the top. The GS-065 bearing would work in that scenario as well. Out of curiosity, I also checked my mast to see if I could turn it easily from the bottom and it wouldn't be hard at all to rotate from the bottom - except for one issue: there isn't enough clearance around the mast tube for my HD-73 rotator, which has an 8" housing width.

I could build a metal cage and plop the entire mast + launcher atop the metal cage and place the rotator below the launcher base plate, then cut a hole through the base plate, etc...

Another method would be to place the rotator beside the mast and use a sprocket and chain. This should also work fine and would be quite doable but I haven't yet found any drive sprockets that would support a 4" bore/shaft diameter. I could of course get around this by reducing the mast size at the base, which is easy enough; then use a smaller drive sprocket.

Anyway, for now I'll move ahead as planned and I thought of another thing to help preserve the rotator. Since I will be guying above (on the thrust bearing) and below the rotator (to the mast), I will put the greater amount of tension on the lower guys and the lesser tension on the upper guys. The upper guys will serve to provide lateral stabilization of the standpipe emerging from the top of the rotator while the lower guys will serve to provide not only lateral stabilization of the mast but also vertical stabilization.

If the top guys are too tight, this will add stress to the rotator bearings which support vertical loading. If the top guys are too loose, this will add stress to the rotator bearings which support horizontal/bend loading.

The greater tension and compression should be on the guys below the rotator but there will have to be a careful balance.

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