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Russell Duffy wrote:
but the talk
of adding weight to the flywheel triggered memory of earlier talk of
'rocking couple' on the 2 rotor engines, which if I read correctly, is
the reason for the counterweights.
All correct as I understand it. When I mention adding weight to the flex
plate, I'm very careful to keep the balance the same. I went so far as to
weight the groups of washers and bolts that I was adding, then mixed and
matched them until I got 4 equally weighted sets. The point of the test was
to add mass, not change the balance.
Is all of your counterweight on one end of the eshaft? If so, could the
engine be rocking, causing the prop blades to not run true?
On a single rotor, the counterweights (one on each end of the shaft) have to
be heavier than normal, and they have to both be opposite of the rotor to
counterbalance the weight of the rotor. I'm pretty confident that there's nothing wrong with the balance of the
rotating assembly. I've run one test without the prop, which completely
eliminated the prop oscillation. That thing was steady as a rock sitting on
the trailer :-) I also got none of the 2500-3100 vibration, nor the drive
rattle at 2000. I'm going to test this one more time without a prop, then
try the IVO prop (two blade, less weight) to see if it changes anything. I'm starting to believe that the dampener system on the RD-1C drive just
isn't going to work for the single rotor. Don't take this as a knock
against the drive, because it works fine for what it was designed to do (2
and 3 rotors). Tracy was very up front about the fact that he had not
considered anyone using it on a single, therefore no reason to believe that
it would be suitable. I knew full well that it might have these problems,
but I figured that some lucky list member may just end up with a discount on
an RD-1C and flex plate combo :-)
Does anyone know if Atkins ever got his single rotor belt drive built, and
if it works? Anyone got a suggestion for a ducted fan that might work for
the Kolb (Bernie, Perry?)
Off to Panama City...
Rusty
You might go on to something with the Warpdrive prop issue. There were several cases of VW cranks being sheared off while running Warpdrives & the 'internet wisdom' was that the carbon blades were so stiff that the torque reversals from the VW (like a mini-Lyc) were killing the shaft because the prop wouldn't absorb the pulses. (The reality was probably that they had just the *wrong* resonant freq & were stronger than the crank.)
At any rate, Warps became verboten on direct drive VW's.
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