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Re: P-47 propellers question

Wed Dec 15, 2010 1:14 pm

Propellors have several components that make up the assembly.
There were 2 manufactures of props used on the P-47, most seem to be Curtis Electrics and some Hamilton Standard.
Both props have the blades, a hub and a device to change the blade angle while in flight. The CE uses an electric motor and the Ham Std uses oil pressure on a piston in the dome. Both the motor and the dome are located on the front of the prop assembly.
Since the prop blades rotate to change the angle of the blade, (bite), then the blade has to be secured so it won't separate from the hub and given bearings that will allow it to move. This also allows different blade types to be fitted to the same hub within a design series.
So yes different blades might be fitted. The hub would be different between 50 and 60 splines.
My CE experience is limited to P-38s but have a bit with the ham std.

Re: P-47 propellers question

Wed Dec 15, 2010 10:45 pm

greatgonzo wrote:Yes, yes, I know the way constant speed propeller works. I m ean I wouldn't design the system but I have the picture :). The question is were the crosschanges possible by CE props - did CE continue to manufacture the blade mounting system with no changes for 6 series. It's logical, but is it real? The other possibility is the change of a spline in the engine, or is it?
The P&W Graham White's book says all the C series engine equiped Thuntherbolts used C642-B40 propeller. I still can't find out is there any connection of the number with the shape of the blade and if the mysterious C-642-B ever existed.

Its easier with HS. Only one type on P-47s.

51 fixer - thank You for Your answer. Moved me a step forward and they all count :).

This has some info-
http://www.enginehistory.org/Propellers ... ssprop.htm
You would really need the part number breakdown of the prop assy's in question.
If the size of the base of the blade matches the size of the blade opening of the hub then the blade could be installed in that hub.
Per the above web page the number designation of the hub and blades would show whether they could be interfaced.

Re: P-47 propellers question

Thu Dec 16, 2010 12:11 am

Hi,
A 60 spline "C" series crank will not fit in a 50 spline "B" series case, as far as I know. The nose case for the "C" series engine is completely different than a "B" series. I will have to give it some more thought on the interchangeablity of the propeller. I would recommend contacting Butch Maxwell of Maxwell propeller at Crystal Airport, Crystal Minnesota. He is still working on counter-weighted HS props and I think he does Hydo-matics as well. He is a real sharp guy, and he might be able to answer your question.

Bill

Re: P-47 propellers question

Thu Dec 16, 2010 7:02 am

BTromblay wrote:Hi,
A 60 spline "C" series crank will not fit in a 50 spline "B" series case, as far as I know. The nose case for the "C" series engine is completely different than a "B" series. I will have to give it some more thought on the interchangeablity of the propeller. I would recommend contacting Butch Maxwell of Maxwell propeller at Crystal Airport, Crystal Minnesota. He is still working on counter-weighted HS props and I think he does Hydo-matics as well. He is a real sharp guy, and he might be able to answer your question.

Bill

I think that the real question is whether the different hubs, 50 vs 60, could use the same prop blades.

Re: P-47 propellers question

Thu Dec 16, 2010 11:36 am

greatgonzo wrote:It is. But the possibility of changing the prop by changing the shaft is a thought too. The reduction case is different in C series but it does not mean the shaft has to be different from engine side. I doubt it would be the same becouse of different gearing systems used by R2800. It is possible to overcome in theory, but I suspect it would need presise tooling as the shaft would have to be dismantled and rebuild and balance problems could have arise.

The real, real question is what was going on with CE P-47 props. I have 3 and let's say 1/2 types of propellers and five confirmed configurations.

I'll try to look for the guy. Thank You for all the help.

The prop shaft that is installed on the 2 types of R-2800 engines mentioned are the same for that series of engine.
In the case of the B engines, there are different gearing on different dash models. The 50 spine shaft is the same though.
It is the same for the 60 spline engines.
The C series could not have a 50 spline prop shaft on the engine AFAIK.
Thus the prop questions of did a 60 spline CE prop hub fit the same blades as the earlier 50 spline hub.

The Aeroproducts series of props used in the P-63, P-51D & H, and even the 2 blade T-28A had the same blade base. There have been Reno Racers that have used 4 T-28A blades on a Merlin.
The Ham Std uses a designation for blade ends such as D. 24D50-XXX is a 4 blade prop with a D blade and 50 spline mount, 23D50 is a 3 blade prop with D blades. The T-6 used a 12D40, 40 spline, 2 blades with a D base.
Wondering how the CE blades were built on the base to see if it is a similar system.

Re: P-47 propellers question

Thu Dec 16, 2010 1:32 pm

The real, real question is what was going on with CE P-47 props. I have 3 and let's say 1/2 types of propellers and five confirmed configurations.

3 propeller assy?

Re: P-47 propellers question

Thu Dec 16, 2010 2:54 pm

greatgonzo wrote: C542S-A6 (toothpick) and later –A114 (asymmetrical Paddleblade) propellers.
C642-B40.
C642-B

C542S-A6- C- Curtis, 5- 50 Spline, 4- 4 Blades, 2- #2 Blade Shank (base), S- Steel Blade. The dash A is the Series, the 6 is the design of that prop assy. It probably references the blade design, limits of the blade angles and maybe small parts that are a part of the assy.
C542S-A114 Same as above but the 114 refers to a different prop assy design but in the same series. It could be only the blades are different but could also address blade angle limits.

C642-B40 Curtis, 60 Spline, 4 Blades, #2 Blade Shank, B series. The B series makes it a different series of prop from the above A series. It could be just the hub is different being 60 spline and a specific blade is called out.

The C642-B possibly would be a generic Prop Assy listing that doesn't reference a specific blade design.

Now that I had a moment to re-read the web page I posted above this is what I think defines these prop models.

Re: P-47 propellers question

Thu Dec 16, 2010 4:32 pm

WOW! CE 101, Thanks Guys

Re: P-47 propellers question

Thu Dec 16, 2010 5:50 pm

greatgonzo wrote:I've seen this page before, but missed one thing. The #2 Shank is repeated in both series (I probably was to lazy to check the new word in the dictionary ;) ). It would suggest the blades to be interchangeable. This could cover the field modifications. I still wander which screws have been mounted on M/N Thunderbolts on the line. The source I mentioned gives B40 for all off them. And which blade is '40'?

The shaft itself could be the same, but I think more of that wheel shaped collar attached to it supporting the planetary reduction gearing. As Republic used three gearing ratios for A/B series and another two basicly for C series, the part would't be the same for all of them. I don't know is it possible to change these parts, but they look like fixed to the shaft strongly to me. But it is another story now.

And which blade is 40?- This is a prop assy number not just a blade number.
On the P-38L IIRC they use C532D-F61 and -F62. I think the -F62 is R/H and -F61 is L/H. One uses 88966-18 blades and the other uses 89303-18 blades. When all the parts are built up into a prop it becomes a -F62 or -F61 depending on the blades and parts used.
More specs on the P-38 can be found on the FAA website. This isn't pure military but what the FAA uses for info. Various props are listed under propellors.
http://www.airweb.faa.gov/Regulatory_an ... L-10-3.pdf
So the -B40 refers to the entire prop built up from specific parts including specified blades.

The shaft itself could be the same- No it isn't. B series had 50 spline prop shafts. This is a SAE designation. The C series had 60 spline prop shafts. There isn't an adapter to put a 50 on a 60 or a 60 on a 50.
As power increased the props had to be beefed up along with the nose case. That is why prop shafts start at 20 spline and go up to 60 spline. A 600 hp T-6 has a 40 spline. A 450 hp 985 has a 30 spline.
The Merlin engines had 2 sets of gears used in the nose case. The gears both would bolt up to the same prop shaft. That is true for the American 50 spline and the British produced British Prop shaft.
The R-2800 is a similar case. Different gearing was used in the nose case but B engines had the 50 spline and C engines had the 60 Spline.
Various engines and there differences are here-
http://www.airweb.faa.gov/Regulatory_an ... I/5E-8.pdf

Re: P-47 propellers question

Fri Dec 17, 2010 5:58 am

Interesting discussion on the P47/2800 and CE propellors.

Has anyone ever seem one around? All of the stics and fliers seem tohave the Ham Standard? I assume the CE's are like hens teeth.

Would be interested in know if there is a hub essembly and blades around anywhere?

regards

MS
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