On 1/2/2013 10:50 PM, Richard (Rick) Karlquist wrote:
On 1/1/2013 7:19 PM, Eugene Jensen wrote:
I personal have no working knowledge of the W3000 worm gear but my only
concern is it design be driven by a drill motor. I use a Thern worm gear
4WM2 motor driven and it is designed for this kind of service. I many
years
ago on a small Hygain Tower blew the gears set driving it with a drill. I
was lucky that it happen at the start. I use mine on the tilt over on a
HDX555. I have used a Hole Hog to drive it. It has two speeds and yes
you
Good point. The W3000 gets hot if you crank it too fast. The Hole Hawg
has a fixed 500 RPM speed. The next model down right angle drill has
variable speed. You need to take it easy with the drill. Keep it
down to 100 or 200 RPM. My W3000 has started to make squeeking noises.
I have been looking for something with a higher rating but most other
winches are only 2000 lbs. I might go with something like what is shown
here:
I think the point to remember is that drill motors are not designed for
continuous duty, not even the heavy duty ones. I burned up a brand new,
heavy duty Dewalt hammer drill, drilling 3/4" holes in a guy anchor
brace in under 5 minutes.
If you look at the motor driven winches, they use a monstrous step down
through spur gears which puts very little load on the motor just as in
the ham series of rotators. The motor itself has so little torque you
can stall it with the pressure from one finger. Drill motors OTOH
provide considerable torque, but generally for a short period as the
motor is small and is not very efficient at getting rid of heat. The
larger rotators using a double worm gear have a motor capable of
substantial torque although the double worm gear multiplies the torque
substantially.
Variable speed Drill motors develop substantial heat when operated at
low speeds/RPM under load. they can not get rid of the heat efficiently
at low RPM and cooling is critical for these small motors. Two speed
drills use gears and run the motor at full speed so they have better
cooling.
This is often a problem with inexpensive winches when used to raise
towers. If it takes 3 minutes to raise the tower make sure the motor
and winch are rated for the load and run time.
A fellow ham who lives a little over a mile from me had one of these
winches fail last fall, with the tower about 2/3rds of the way up or
around 60 degrees. Got pretty busy there for a while.
A 1/4 to 1/3rd horse, 1700 rpm AC motor should likely be sufficient when
geared down to tower raising speeds be it tilt up or extension speeds.
I'd run the calcs before actually trying it though.
Small to medium size motors designed for continuous duty, or at least
long run times when operated within their load limits stand up quite well.
BTW RPM should not have an "S" as in RPMS although it's often mistakenly
written that way. RPM stands for revolutions per minute. Put an S on
that and it doesn't make sense as it'd be revolutions per minutes which
is acceleration.
73 Roger (K8RI)
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