[TowerTalk] Stuck Rotator

[K8RI on TowerTalk]

I'm going to try and address both Rich and Jeff in this post and as this was 
sent off list which should have not made it past the filters and I don't 
know why, I'll do a bit more editing.

I should point out that mine is the older "green" unit with the AC motor. I 
had to mount the motor horizontally to get it to fit into the ROHN 45G.  I 
understand the new ones have a much better top seal, but I've not seen one. 
I'll also add that I do like the rotator and believe the shortcomings have 
been designed out in the newer models.

> Hi Roger,
> Oh Yes, I have a PST 61 and the same thing happened. We could not get the
> bearing off even with a 50 ton press. I contacted Prosistel and dealt with

Note in photo 2  on  http://www.rogerhalstead.com/Gears.htm you see what 
appear to be well defined rings around the shaft.  Now look at photo 4.  The 
deeply pitted area on the shaft in this photo is that rust colored area in 
the photo referenced above. Those rings are just patterns in the rust/lube 
mix.

I'm fortunate "I think" in that I have worked on *stuff* similar to this 
many times in the distant past.  Getting something like this apart that has 
been pressed together depends a bit on experience, knowing where it comes 
apart, where it needs to be supported, and how to get it apart. 
Successfully getting it apart is part of the above, part luck, part which 
way the wind is blowing, whether your language intimidated it, the phase of 
the moon AND a good penetrating oil.

<snip>

Having the equipment and background sure does help when it comes to pressing 
out the shaft, getting the frozen bearing races off and then putting the 
whole thing back together.

<snip>

Likewise I was a bit disappointed that the seal failed and created so much 
damage in a bit under 5 years.

The center shaft on mine has two keyways in it. They only use one, but the 
second one apparently was a first try.  It sort of spirals a bit to the left 
and gets a lot shallower toward the one end so I'd guess it came loose in 
the fixture during the milling operation.  That's an interesting photo, but 
I've not put it up and it's not germain to the problem.

I had reservations about that top seal the first time I saw water setting on 
it.
I'm going to design something to go on top to keep water from collecting in 
that depression.  At the least the top seal should have been flush with the 
top of the housing so the water would not collect in there.  OTOH those are 
standard oil seals, which are very good seals but the design is such that 
the wiper forms a grove pointing in which means the water should be kept 
away from there as it can collect in the grove. That's probably what created 
the concentric rings in the rust in photo 2.

BTW one of our locals created a bearing protector out of a spray paint can 
top. He cut a hole in the plastic top so the mast is a slip fit, put it in 
position over the bearing and then RTV'd the top to the mast. He's had it up 
for years.

> caulk around the shaft. I have also fabricated a old hubcap from a Lincoln
> that fits on the top of the shaft plate and is a large rain, snow ice
> shield.

Remember that reguardless of how well you seal it the rotator housing will 
breathe. You want to control where and how it breathes to keep water out and 
condensation to a minimum. That recess/depression at the top seal really 
needs to be eliminated some how.

I've added a bit more to that page http://www.rogerhalstead.com/Gears.htm 
and reworded some of it. I've also reduced the image size and resolution a 
bit so they are now about 100K each instead of 750K.

I'll add the step-by-step procedure I followed to disassemble it as well, 
but I offer no gurantees that my way is the proper way. <:-)) Hopefully 
it'll make it easier for some one trying to take one apart, or do some 
repair.

I should probably change it to small images like those on my tower project 
with links to full screen images. That way the page would load much faster 
and the detail would be there for those who really wanted to see it. OTOH 
I'm not sure I have that much ambition. <:-))

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from here)
>
> Also I have it on a HDBX 48 and have put the rotor plate which I made at 
> 44"
> off the ground.
>
> Good Luck,  Any questions please email and if you like I'll send my pics 
> to
> you.
>
> Rick McGaver   NK9G
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com]On Behalf Of K8RI on TowerTalk
> Sent: Tuesday, July 25, 2006 7:38 PM
> To: TOWERTALK at contesting.com
> Subject: Re: [TowerTalk] Stuck Rotator
>
>
> <snip>
>>
>> The distributor (Jay) has been very helpful in getting this thing apart.
>> I've now reached the point where it's time for a hydraulic press to get
>> the
>> shaft out of the gear and the top bearing off.  IF I don't brake anything
>> the only parts needed will be the two bearings and oil seals.
>>
>> That big bronze gear appears to have been cast onto the steel inner
>> support.
>> As the bronze gear is thicker than the support it means supporting the
>> steel
>> flange rather than the brass when pressing out the shaft.  The whole 
>> works
>> has been soaking in PB blaster for the last two days.
>
> We split a bearing race and used it to support the steel inner part of the
> worm gear wheel.  The shaft pressed out easily.  It did take a bit more 
> work
> to get the inner race for the top bearing off, but it still was no big 
> deal.
> OTOH The sealing surface for the upper oil seal is pretty well shot.  The
> surface for the bottom seal is a bit rough but I think that could be
> salvaged. Still I have to be able to use both ends of the gear.
>
>>
>> If any one is interested AND has a high speed internet connection there
>> are
>> three LARGE high resolution photos of the insides at
>
> There are now five and I have reduced the size to 100K per file, give or
> take a tad. I added two that show the upper and lower sealing surfaces.
>
>> http://www.rogerhalstead.com/Gears.htm
>
> There's a bit more information at the bottom of my tower project page
> http://www.rogerhalstead.com/ham_files/tower.htm
>
> Roger Halstead (K8RI and ARRL 40 year Life Member)
> N833R - World's oldest Debonair CD-2
> www.rogerhalstead.com (Use return address from here)
>>
>> BTW my address has changed and the only accepted sender to this one is 
>> the
>> reflector.  Direct replies/e-mails should go to an address on my home
>> page.
>> Sorry about the round about method, but the old address here was getting
>> more spam every day.
>>
>> Roger Halstead (K8RI and ARRL 40 year Life Member)
>> N833R - World's oldest Debonair CD-2
>> www.rogerhalstead.com
<snip>