P-51D Propeller

[mazaker]

I would like to try machining a Hamilton Standard propeller.
Does any one have any detailed drawings or cad models of one.

[Greg1651]

Which blade cuffed or paddle? What are you going to machine them out of? What scale are you going to machine?

[mazaker]

Cuffed, and I'm not sure what scale yet. I am working with a friend that is building a P-51 RC with 100" wing span.

[CarveOne]

Try this link to find other links to drawings that might get you closer to what you are looking for.

If you are wanting to make a scale propeller just to use for scale display points you should proceed. No one here will recommend doing it for in flight uses. The safety risk of prop failure is just too great.

CarveOne

[edge540]

I agree w/ Carveone. If you were going to scale the prop to the plane it would be huge by comparison to a typical prop for a 100" plane. my 102" 33% Edge spins a 28" prop at 6500. Just guessing but scale wise I would think you would be well into the thirties and would need a gear reduction. Being that its a P-51 it probabley wont have the best flight characteristics anyway as far as models (scale warbirds can be nasty. I know) go and the forces (torque, p-factor, spiral slipstream, gyroscopic precession) created by such a large prop may be unpredictable at best. Also because of the surface area of such a large, scale blade it would have to be pretty thin to have half decent efficiency and thats where engineering would be required to obtain sufficient mechanical properties. be careful. hate to see you guys crash on the maiden or worse.

[CarveOne]

I agree w/ Carveone. If you were going to scale the prop to the plane it would be huge by comparison to a typical prop for a 100" plane. my 102" 33% Edge spins a 28" prop at 6500. Just guessing but scale wise I would think you would be well into the thirties and would need a gear reduction. Being that its a P-51 it probabley wont have the best flight characteristics anyway as far as models (scale warbirds can be nasty. I know) go and the forces (torque, p-factor, spiral slipstream, gyroscopic precession) created by such a large prop may be unpredictable at best. Also because of the surface area of such a large, scale blade it would have to be pretty thin to have half decent efficiency and thats where engineering would be required to obtain sufficient mechanical properties. be careful. hate to see you guys crash on the maiden or worse.

Building a prop to run on a gasoline or glow engine is as much engineering art as it is science. Same as with full scale props. The reason for my "disclaimer" is that I've seen the results of attempts to run spliced props on R/C models in my 40 years of building and flying them. Even CNC machining a three or four blade prop from aluminum would give me the willies to see someone cranking up an engine with one on it. I don't know anything about mazaker's knowledge of the subject, and don't mean to be insulting. I just want everyone to be be very careful with powered props.

My employer and I built two 21" rotors for a wind tunnel model of the V-22 Osprey about three years ago. It had a machined aluminum two piece hub and individual blades that had an aluminum core, dense carbon fiber cloth, carbon fiber flocking, and unidirectional carbon fiber strips in it, all held together with West Systems slow cure epoxy and was vacuum formed in CNC machined molds. The blades were individually matched in weight, then balanced as an assembly. What a real pain to accomplish accurately and vibration free. The blades could rotate in the hub and the pitch of each blade be set with a precision blade pitch gauge. They ran on Hacker C50 geared motors at over 5k rpm for short spurts for wind tunnel measurements. We would never have run those on a piston engine. We make no claims of being experts just because we were successful that one time.

CarveOne

[edge540]

not to mention metal props are forbiden under AMA Rules

[CarveOne]

not to mention metal props are forbiden under AMA Rules

For very good reasons too.

CarveOne