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Lynn,
Good info on balancing the two rotors.
Does the rotor have to balanced within itself for a best balancing outcome.
I'm doing a 'single rotor' and was wondering if I need to go that far.
George ( down under)
It all sounds good to me. The Japs are anal about a lot of things, and
getting the engine smoother than any piston engine was way high on the
list. It has
a built in rocking couple problem, and a built in torque amplitude
problem. So
the counter weights take out the rocking couple, and the 40 pound flywheel
evens out the torque pulses. Presto, smoother than any piston engine.
So, if you have two good rotors and they have different weights, what to
do?
Build one hell of a sensitive scale. Then use your drill press to remove
tiny
amounts of steel from the heavy rotor, until both are the same weight. Use
the counterweights from the lighter rotor's engine.
The scale can be anything stiff. Like a 2X4 or pieces of square tubing or
round tubing, maybe 6 feet long. The pivot is to be two sharpened bolts
through
the (whatever) bar. Then two bent up hangers. Cut two steel 3/8" rods the
same
length to start with. Sharpen one end to a fine point, and bend that end
into
a 180 with a radius big enough to clear the end of the bar. The other end
can
be just a hook to grab the rotor through an oil opening, or a real nice
flat
90 to sit in the bearing hole.
If your bar is wood nail a scrap of steel plate to each end in exactly the
same place.
Put a punch mark on one plate or on one end of the square stock close to
the
end. Make the hangers just long enough so that a rotor on each one will
just
clear the floor, or bench.
With just the hangers, hang one on where your punch mark is installed.
Hang
the other in a location that just balances the scale. Reverse the hangers
to be
sure they weigh the same. Grind off as required. Mark the location of the
second hanger, and make a punch mark for that one. The punch make is to
make a
location that can be found every time, so make just a mark, don't beat a
big
depression. The sharp points and hard surfaces generate a near zero
friction
pivot point.
Support the pivot bolt ends on a flat plate between jack stands, or cement
blocks, whatever.
Hang any two rotors. Dump pennies or (If its close) paper clips to
balance.
Then reverse the hangers with the rotors left on them to be sure the
answer is
the same.
Drill a bit (use a drill stop) from the corner area (look where the
factory
did it) and reweigh. After two passes, drill a set on the opposite side of
the
rotor.
If you think it through, you can build a scale that can "see" a paper
clip.
And that is close enough. You will notice that the fans must be off, and
the
doors closed.
Lynn E. Hanover
>> Homepage: http://www.flyrotary.com/
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