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Hi Kelly,
Like making allowances for the oil capacity of the
rotor, I can't tell you ALL my secrets!! I'm pretty free with
info, but this particular one falls into the category of "trade
secret".
Other guys make up mandrels and attach weights as
is done in normal piston engine balancing practice. But that is time
consuming. One added complication is that the rotor has the cetre of
mass biased slightly on the gear side, so even though the mass centroid
co-incides with the centre line of the eccentric journal, it's not
midway ON the journal.
This distance varies slightly from rotor model
to rotor model (the transfer gear is the same weight, but the lighter the
rotor, the more this shifts towards to gear side, especially with
rotors that have been extensively lightened for racing.
So it's far easier just to use the rotor itself
(with the seals taped in), and then we have all the masses exactly where
they are supposed to be when the engine is running.
As for indexing the actual rotor, if you
think about it, the centroid of mass of the rotor, being basically
an equilateral triangle, is at the centre line of the lobe. So it
doesn't matter how the rotor is "clocked" in relationship to the
eccentric lobe. (I just can't wait for some mathematically obsessed
theoretician to try to "prove" that this isn't the case). (}:>)
Cheers,
Leon
----- Original Message -----
Sent: Monday, January 17, 2005 3:33
AM
Subject: [FlyRotary] Re: 3 Rotor
Balancing Stuff
Leon,
How are rotors kept in place on shaft and are they
indexed
relative to each other as they are in a running engine ?
--
Kelly Troyer
Dyke
Delta/13B/RD1C/EC2
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Original message from "Leon" <peon@pacific.net.au>:
--------------
> Here's another couple of pix to show a 3
rotor being balanced. Notice the
> Mallory Metal added to the front
counterweight to shift the balance axis.
> The factory front
counterweight was originally drilled off centre by the
> factory due
to the rotors not all being the same weight. During balancing,
> all
the rotors were reduced back to the same dynamic weight as the lightest.
> Then put on the shaft.
>
> Cheers,
>
>
Leon
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