The typical powered extensions and tilts supplied with towers that I've
seen, use multiple belt and pulley speed reductions so the typical 1700
RPM motor is lightly loaded with temperature not a problem. There are
many I've not seen, but it's an inexpensive way to make tilt and
extension easy so I'd expect the method to be quite common.
They remind me of our first self propelled lawn mower. One day my
father took one of our reel type push mowers to the welding shop. What
he brought home would have made Rube Goldberg proud...and it worked. It
had a wood platform above the mower on which a kick start washing
machine motor was mounted. How many on here have seen a washing machine
powered by a gas engine? 2-cycle with a governor on the ignition had a
unique sound. There were IIRC 3 parallel shafts connected with a series
of small to large pulley speed reductions. A few years later Western
Auto came out with a 2-cycle powered lawn mower with a 14 or 16" blade.
I think the blade tips were near supersonic. It would chop up a piece
of wire and spit the pieces out like bullets!
At any rate, back to speed reducers. The belt and pulley speed reducers
(torque multipliers) have been around for decades since when electric
motors were inefficient and expensive for the day. They are cheap,
efficient, work well, easy to adjust, and are easy to maintain. My
neighbor's motorized crank up runs effortlessly, albeit slow, using a
conventional size electric motor rather than the tiny ones we are used
to seeing. Using a full size motor with no time limit at their full
load ratings. Silent, quiet, dependable, and inexpensive. Plus they
only require enough space for cooling by the surrounding air. Price
from the tower manufacturer too high? Look around. Nearly every
hardware store and big box store has them, usually at very reasonable
prices, but be careful of undersize imports.
73
Roger (K8RI)
On 6/30/2015 8:35 AM, Patrick Greenlee wrote:
As my on-order-but- not-delivered-yet new Tashjian tower has 2 each
1/2 HP motors, one for extend and power retract and the other for
tilt, I don't worry too much about manual cranking. I don't recall the
gear reduction ratio but it was substantial, sufficient that I'd not
want to have to crank it and crank it... manually. No one mentioned
anything about an option for cooling fans or cooling coils for the
winches. ;) ;)
Patrick NJ5G
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