These bearings have been used by most of the major tower manufacturers over
the last 40 years or longer. They are the bearings that are pressed into
the aluminum cable pulley that guides the lifting cables for our amateur
radio crank up towers. They are not exactly waterproof but do have an
outside seal that does help keep out the dust. As mentioned by Grant,
KZ1W, in many cases, the bearing may be frozen but with soaking in a
peneratrant, they can be freed up and used again. Personally, I use
combination paint thinner and automatic transmission fluid (ATF) in an
ultrasound, vibrating tub that will often clean and free them up. Once
cleaned, you can hold and rotate the bearing to feel if the bearing is
internally pitted. If it is, get rid of it!
As far as I know, Fafnir was one of the original manufacturers and supplied
them for the German WWII effort. SKF was probably another, but they were
bombed out of existance during WWII. Later Fafnir expanded to the USA and
other countries. Timkin and Torrington are some of the more recent
manufacturers.
Be aware, the K8 and KP8A are not the same! You want the K8 bearings for
this use!
If you have any questions, please ask me or Grant, KZ1W. Grant and I have
never met, but I have always respected his mechanical experience, as seen
by his many posts on the TT reflector.
Ray,
N6VR/W7YA
On Mon, Mar 21, 2022 at 3:16 PM Grant Saviers <grants2@pacbell.net> wrote:
> Having obtained some from aircaft control cable pulleys marked "Boeing"
> the ORIGINAL use was just that. One crank up tower maker actually had
> pulleys marked Boeing with these bearings rusted solid that I replaced.
> With the wider inner race the pulley flanges and cables don't rub on
> the mounts.
>
> Note the 1998 date on the ebay box. Fafnir doesn't make these any more
> AFAIK. In 1989, I asked them to make an out of production bearing about
> this size they said, "We can do it since we have the prints. $50,000 for
> set up and 1000 bearings". I found away to substitute.
>
> Best to soak these in oil for a while, since the grease is now 34 years
> old.
>
> Grant KZ1W
>
> On 3/21/2022 14:53, Jon Zaimes, AA1K via TowerTalk wrote:
> > Found them here:
> https://www.ebay.com/itm/154716606730?hash=item2405d4110a:g:EbUAAOSwr3VhnbE9
> > What is their specific use?
> >
> > 73/Jon
> > Jon P. Zaimes, AA1K Tower climber for hire http://www.aa1k.us/ Cell:
> 302-632-2353email: jz73@verizon.net or aa1k@arrl.net
> >
> > -----Original Message-----
> > From: Raymond Benny <rayn6vr@gmail.com>
> > To: Tower Talk <TowerTalk@contesting.com>
> > Sent: Mon, Mar 21, 2022 4:47 pm
> > Subject: [TowerTalk] Fwd: K8 Bearing available
> >
> > Guess I don't know what I am doing.
> >
> > Go to eBay and do a search on " Torrington Fafnir Aircraft Bearings KP8
> > FS428 New - FREE shipping" This worked for me.
> >
> > Ray,
> > N6VR/W7YA
> >
> >
> > ---------- Forwarded message ---------
> > From: Mike Ryan <mryan001@tampabay.rr.com>
> > Date: Mon, Mar 21, 2022 at 1:33 PM
> > Subject: RE: [TowerTalk] K8 Bearing available
> > To: Raymond Benny <rayn6vr@gmail.com>
> >
> >
> > Nothing seen from the link you provided. Thanks anyway... - Mike
> >
> > -----Original Message-----
> > From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
> > Raymond Benny
> > Sent: Monday, March 21, 2022 4:14 PM
> > To: Tower Talk
> > Subject: [TowerTalk] K8 Bearing available
> >
> > Here is a link to eBay for some K8 bearings. Price is $17.95, shipping
> > included. The seller says "bearings" so there may be more than one
> > available.
> >
> > https://mail.google.com/mail/u/0/#inbox/FMfcgzGmvVCwZSvgkmpzJWpMGQKDChQb
> >
> > You can't beat the price anywhere.
> >
> > Ray,
> > N6VR/W7YA
> > _______________________________________________
> >
> >
> >
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> > TowerTalk@contesting.com
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> >
> >
> >
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> >
> >
> >
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