Oh,oh...I feel a "..we're going to beat this subject to death..." coming on.
Anyone want to talk about seabirds again instead? - Mike
[mailto:email@example.com]On Behalf Of K8RI
Sent: Wednesday, March 21, 2007 2:08 PM
Subject: Re: [TowerTalk] Inexpensive thrust bearing?
You can build a thrust bearing for pennies or maybe a few dollars that is
far superior to most commercial thrust bearings particularly if it is used
to keep the mast centered and does not serve as a support which they
shouldn't in most cases.
I'm getting rid of my ROHN thrust bearings (lot more than $50) and replacing
them with a piece of pipe about 18" long, albeit the finished product will
be a bit more elaborate than most think of when a piece of pipe is
mentioned. As far as binding, or freezing you simply get a sheet of
silicone rubber long enough to go around the mast and pipe at least one and
a half times. I prefer a bit over two times.wrap it around the mast so it
extends down over the pipe by at least 3 or 4 inches. Use a SS hose clamp to
hold it in place on the mast. If need be a bit of Lithium grease can be
added where it slides on the pipe/thrust bearing.
The wood bearing or "Amateur Block" when constructed properly also has the
advantage of being adjustable. For that I'd use oil impregnated hard wood.
> You get what you pay for. An inexpensive (aka cheap) thrust bearing or
> substitute device (not recommended) may in the long run cost you more in
It depends on how elaborate you want to get, but from what I've seen, most
inexpensive thrust bearings are more reliable and serve the function of a
thrust bearing better than the commercial ones.
> time and frustration than if you spent the $50 in the first place. A
> bearing that freezes up, rusts out, binds, etc especially in the middle of
> winter when tower climbing, mast and antenna pulling, etc. is impossible
It only takes a little thought to prevent these things from happening.
> unsafe can make the money you should have spent to do it right in the
> place not seem excessive.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from home page)
>>From: Rob Frohne <firstname.lastname@example.org>
>>Subject: [TowerTalk] Inexpensive thrust bearing?
>>Date: Wed, 21 Mar 2007 10:06:59 -0700
>>Does anyone have a source for an inexpensive thrust bearing? I have a
>>plate on the top of my tower with a hole through it, and was thinking of
>>putting a thrust bearing on, but the ones I found were around $50 which
>>for my frugal self is a bit spendy for a thrust bearing. It seems that
>>there is probably a cheaper way to do this with some kind of automobile
>>bearing or a sleeve of pipe and some set screws, etc. Does anyone have
>>Rob Frohne, Ph.D., P.E.
>>E.F. Cross School of Engineering
>>Walla Walla College
>>100 SW 4th Street
>>College Place, WA 99324
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