Bob Maser wrote:
> I've read reports that indicate that the Prosistel rotors have serious
> quality problems and they ain't cheap. In fact, I turned down a hell of a
> deal on a Prosistel 71 and found a PP instead. Italians are lovers, not
> engineers.
>
The only design problem I've seen so far has been the top seal in the
OLD STYLE housings. The seal in those is surrounded by a reinforcement
ridge in the casting creating a depression between a quarter and a half
inch deep where water can collect. This then causes corrosion on the top
shaft and ruins the seal. This then results in water getting into the
housing causing the bearings to deteriorate. However, nearly
everything in the rotator including seals is available "off-the-shelf"
from your local NAPA auto parts dealer. The top and bottom bearings are
"wheel bearings" meaning they are far more rugged than we typically
see. The only thing I've not found available "off-the-shelf" has been
the large worm gear wheel and worm. Even there, I'm sure I could find a
replacement worm and wheel that could be used. Probably one that is
more readily available. There were some minor problems with the digital
controllers, but nothing I've seen that I would consider serious.
http://www.rogerhalstead.com/Gears.htm shows what can happen when water
gets in. I need to finish up the page to show what I did to keep water
out. Another thing I did was to replace the gear lube with white Lithium
grease. I basically packed the rotator with the stuff although it
doesn't need more than a coating on the gears and the wheel bearings
packed...like wheel bearings.
The housing has been redesigned, the motors changed to DC that operate
over a wide voltage range, and there are several size motors available.
They are also available with the Green Heron controllers instead of the
ProsisTel controllers.
I only see two problems with the current rotators. They are big and
expensive.
The seal problem on the older housings is easily overcome. If you find
another "whale-of-a-deal" on a PST61 or 71 send them my way. I'd not
hesitate to use one. OTOH I'm not exactly flush with cash at the
moment. (To many projects underway including a new zero turning radius
lawn mower for a large yard)<:-))
73
Roger (K8RI)
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