SNIP<

A four inch tube six inches long .125 inches thick would weigh about
about 2.8 pounds. 9.42 cubic inches 6.78 cubic inches or 2 pounds out
of .090. I would try the .125 wall first to be conservative.
As there is combined bending and torque on the tube.

A six inch dia prop flange .25 inch thick weighs about 2 pounds alone.
a six inch long 1.3875 dia (9 cubic inch) shaft weighs about 2.75 pounds
not including the material in the fillet or holes in the flange.
A ball bearing for this shaft would weigh another pound. Total
about 5-1/2 to six pounds. Less if bored out. Tracy does not
recommend metal props for his psru.
SNIP<
Paul Lamar

The "No metal prop" recommendation was for the old RD-1 (no longer in
production) which had a 35mm [1.375"] prop shaft made from the C6 transmission output
shaft. 

The RD-1A/B/C  prop shaft and hub is a much stronger 4340 one piece forging
and has no limitation on propeller weight.  Metal prop is OK for these
models.

Tracy Crook

What is the new prop shaft diameter and weight Tracy?

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.