Gremont propeller

tbusby61 · 6 October 2009, 09:49 AM

Does anyone know the pitch of the Gremont propeller as used on the Caudron G4?

Thanks,
Terry

mik · 2 November 2009, 03:28 PM

In short no! but an estimate is possible.
the G4 does 130kph flat out and rotary engines do about 1300rpm
Based on these figures the plane moves about 36.11 meters/sec.
The engine does about 21.66revs/sec
Therefore 36.11 divided by 21.66 gives the pitch of1.67 meters or 65.75 inches which in case you don't know is how far the plane moves for 1 revolution of the propeller.
mik

RobW · 2 November 2009, 04:49 PM

funny thing... this weekend, one of the speakers at the league of WWI aviation historians meeting at the Smithsonian is building a G4 model and was taking measurements off of the one there at Udvar - Hazy. Perhaps aerodrome member Charles can link you up with him. I'd send him a PM.

Rob

YavorD · 3 November 2009, 01:34 AM

Caudron G.4 Le Rhône 80 ch
Grémont série CT
Dia 2.50 m
Pas 1.90 m
Moyeu épaisseur 100 mm
Source: Les héliciers français par Gérard Hartmann (scroll down)

Regards,
Yavor

tbusby61 · 3 November 2009, 03:46 PM

Thanks for all the replys. I received the same information on the Wooden Propeller website. Yavor, thanks for the attachment to your reply. It is full of great information....just need to translate. Rob, I am the person who spoke at the league meeting... thanks for your help by the way!

Terry

RobW · 3 November 2009, 04:51 PM

Quote:

Originally Posted by tbusby61

Rob, I am the person who spoke at the league meeting... thanks for your help by the way!

Terry

Rats... oh well... Glad I could help in person at least...

Did you figure out the translation part? I use several online translators and could help you with that if you wish.

Are you posting pictures of the build... would love to see a thread on that.

Rob

tbusby61 · 4 November 2009, 04:49 PM

Rob
For translation I use either Google or Microsoft Translate. They are OK for words and some phrases but are highly unsatisfactory for entire documents. Any advice would be appreciated.

Regarding the Gremont propeller as you know I measured the actual hub thickness.... it is 125 mm, not the 100 mm the specification listed in "Les héliciers français par Gérard Hartmann". Not sure what to make of that. The scale drawings also indicate a dia. of approx. 2.7M as opposed to the spec of 2.5M. Yavor or anybody have comments? Now I suppose I will have to measure the entire prop.

Terry

YavorD · 5 November 2009, 01:40 AM

2.7 m Diameter is too big for a Le Rhône 9C (80 ch). It is more likely for a 9J (Jb) of 110(120) ch.
Regards,
Yavor