I wonder if the pulley and bearing assemblies could be replaced with one that
has a grease fitting.
I would love that !!
Bob
K6UJ
On Sep 4, 2012, at 9:30 PM, Ray Benny wrote:
> Speaking of cable pulley bearings, if you care to replace one yourself,
> instead of paying $80 or so for the pulley and bearing, they (the bearing)
> can be purchased usually NIB on eBay for $10 - $20 each. You may have to
> create an eBay search on your account to find one when it shows up.
>
> One of the more common bearing used is the KP8 or KP8A. Perhaps you can get
> the bearing info from your tower manufacturer. Or, you may have to remove
> one of your pulleys when you have the chance and see which you have.
> Different size pulleys have different size bearing pressed into them.
>
> Removing a pulley requires knowledge on what you are doing. If you are not
> mechanically inclined, don't try it. It can be dangerous. But done
> correctly, its not difficult and can the pulley can removed safely. You'll
> need slack in the cable and blocking one of the tower sections when
> lowering the tower is one way to do it. But, if you have a pull down cable,
> don't go so far down as to put too much tension on that cable. If you are
> working on the bottom tower section, you may have a cable tensioning
> spring. Removing tension on the spring might be enough to provide enough
> slack to remove that pulley.
>
> Perhaps another way to provide cable slack is to raise the upper tower
> section with a come-along. I've never done it that way and not sure if it
> will pull up lower section too.
>
> The safest way would be to have your tower laying on the ground or in the
> horizontal position.
>
> Again, know what you are doing before you try!
>
> Ray,
> N6VR
>
> On Tue, Sep 4, 2012 at 8:43 PM, <NPAlex@aol.com> wrote:
>
>>
>> Steve,
>>
>> Having had one LM-470 crank up cable fail because a pulley bearing had
>> rusted and would not turn, and the added stress caused the failure. Sealed
>> or
>> not here in Florida they get water inside. I also had a frozen bearing on
>> my current US 589 tower, fortunately it was on the pull down cable and not
>> a
>> high risk.
>>
>> Each of these pulley bearings are of the closed , ball bearing design, but
>> have had water intrusion and rusted. Once rusted it is easy for the
>> bearing balls to become misshapen and then freeze the pulley - I am
>> sticking
>> with my recommendation as it has happened to me.
>>
>> Norm W4QN
>> ===========================================
>>
>> In a message dated 9/4/2012 1:57:44 P.M. Eastern Daylight Time,
>> K7LXC@aol.com writes:
>>
>>> So my recommendation is to regularly lube the cables, and rigorously
>> grease the pulley bearings. Because the pulley bearings are deep within a
>> 'sheave' I recommend drilling a small hole (1/8") next to the pulley
>> mounting
>> bolt so that a lubricant can be squirted directly into the bearing
>>
>> It's probably not necessary. For years, UST (and others I'm sure) have
>> used pulleys with pressed-in sealed bearings so no attention is needed.
>> OTOH if your pulleys have bushings instead, periodic lubing is a good
>> practice.
>>
>> Cheers,
>> Steve K7LXC
>> TOWER TECH
>>
>>
>>
>>
>> _______________________________________________
>>
>>
>>
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