Monday, September 29, 2014

Propeller Hub for WWI 80 HP Le Rhone Rotary Motor

 Back in January 2013 I wrote about de-rusting a propeller hub and then discovering it was a metric hub.  I've just learned that this hub fits an engine from earlier in the First World War.  It's for an 80 HP Le Rhone rotary motor.  It does not fit the larger motors like the 110 HP version.  It may fit the 60 HP version but I have not found data for the hub on it and they only made a few hundred of them.

 The first piece of data was from The Handbook of Instructions for Airplane Designers, second edition, February, 1921.  This book was produced by the Engineering Division of the Air Service.  The focus is on the dimensions which are relevant to making the propeller.  The dimensions are:

A - Hub Shaft O.D. 60 mm (2.362")
C - Prop. Bolt Centerline Diameter 120 mm (4.724")
D - Hub Flange O.D. 150 mm (5.905")
E - Number of Bolts - 8
F - Dia. of Bolts - 10 mm (0.394")
On-line I found some drawings which show the dimensions related to attaching the hub to the shaft.

The shaft is 42 mm O.D. at the nut end of the shaft.
The taper increases the diameter as a 10% cone.
The threaded end of the shaft (where the retaining nut screws on)
    is threaded for 18 mm.
The thread has on O.D. of 40 mm and a pitch of 1.50 mm.

All of which says this hub works on an 80 HP Le Rhone.  With magnetic inspection for cracks and fresh nickle plating it would be ready for use.

Anyone need a prop hub for their project?
Some of the planes which used the 80 HP Le Rhone either as the primary or alternate motor were:

1913 - Morane-Saulier L
1913 - Morane-Saulier N
1914 - Nieuport 10
1915 - Nieuport 11 (Bebe)
1916 - Nieuport 21 (as trainers)
1914 - Bristol Scout C
1915 - Bristol Scout D
1915 - SPAD A-2
1916 - Sopwith Pup
1916 - Vickers F.B.12
1917 - Thomas-Morse S4c