[TowerTalk] Yaesu GS-065 thrust bearing

[Roger (K8RI) on TT]

On 6/2/2014 1:12 PM, David Robbins wrote:
> I have a tb-3 that has been in the air for almost 30 years now, has outlived several rotors, a bunch of antennas, and a set of guy wires... and I haven't looked at it since I put it up there... it just keeps on turning.  I have several others on different towers that have been up there 15 to 20 years that have never been touched either.  just how old are these tb-3's that are requiring all this work???  have they been used in a salt spray environment?

Welll...I'm in central Michigan. About 25 miles from Saginaw Bay (fresh 
water) and many hundreds of miles from salt water, unless you count our 
winter roads. <:-)) I went through a TB-3 and a TB-4 in less than 6 
years. The races wore to the point that the top sat on the bottom and 
the edges of the races were like razor blades

Admittedly, I overloaded them, but wanted to see if they'd stand up.  I 
don't have the name handy, but there are bearings available that 
twist-lock to the mast and come in 2 and 4 bolt mounts.  I'm sure some 
of the group have the names and numbers.

They do need a slight mod to keep water from collecting on the bearing.  
They are smoother, stronger, and a fraction of the cost of TB series of 
bearings.  They do require a yearly greasing (probably more often when 
located near the coast.)

>
> Jun 2, 2014 01:03:10 PM, charlie at thegallos.com wrote:
>
> Exactly what I'd do if I needed to rebuild a thrust bearing, unless I could get some free torlon or vespel (haha, I'm funny, those are crazy expensive and overkill)
>
> Low rotation rate, shock loaded, out in the weather, where they wi

Tip over towers that slightly invert the mast when down, only need a 
collar or collars to prevent the mast from sliding out with "Plastic 
bearings". A plastic washer between the collars might help.

73

Roger (K8RI)

> ll receive little in the way of maintenance is the place where engineering plastics like nylatron gsm shine. Heck, I can't see why any tower thrust bearing mfg would do anything else except to market to folks who say "ball bearings have to be better than PLASTIC"
>