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.
A tough gig, hard on the body and the drill.
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.
The "Hole Hawg" is geared way down and I think will handle long on time
duty cycles. It's designed for drilling through lots of studs for piping.
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.
Here is my favorite, torque that can hurt, 2 speeds for metal or wood.
I've drilled dozens of 9/16" holes in 3/8 steel plate non-stop using
split point cobalt drills. It wasn't fun. A Mag-Drill would have made
it easier but was too heavy to schlep to the remote site.
http://www.milwaukeetool.com/tools/rotary-hammers-and-hammer-drills/hammer-drills-corded/1-2-inch-dual-speed-hammer-drill-kit/5387-22
$180 at HD.
It is also very fast as a hammer drill in concrete, but you need a top
quality carbide drill bit and some luck in missing the rebar.
Grant KZ1W
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