From: echristley@nc.rr.com
Date: 2005/07/01 Fri PM 12:05:11 EDT
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: [FlyRotary] Trials and tribulations of secondhand projects

I was told, or at least made to understand, or...well...I'm not even
sure anymore (I think I'm getting old).  But I thought that the gearset
in my custom built PSRU came from a C4 transmission.  I was even told,
by a transmission technician, that the gearset I had was used in busses
(sp?), but after several warnings I thought it would be a good idea to
switch the 3-pinion planet for a 6-pinion.  It was only $218...cheap
peace of mind, even if it didn't make any difference.

The part came yesterday.  Props to those of you who can figure out why I
feel a little disappointment.

Can anybody shed any light onto what I have on my hands from the
pictures?  The only thing I know for sure is that the smaller set is
indeed a C4 forward gear set.

BTW, ratios.  For you guys wanting to run PPs at high RPM and willing to
build their own reduction unit, this may be an excellent choice.  I
counted sun and ring gear teeth, but can't remember the exact count.
But with a locked ring, and taking the output from the planet splines,
you'd get a reduction of somewhere around 3.2.   I'll count again when I
get home if anyone is really interested.