Prop Parts at FAAM (2 Viewers)

[Engineman]

Hi Larry!
Well, the inside of the spider looks to have cleaned-up. The rear opening for the propshaft looks to still have a large spring circlip retaining the front cone or spacers. That could possibly be removed, those parts could have marks.
As far as the splines go, I feel that they may also hold the ID clues. Most national products used particular type and sized splines, and those look good enough to be accurately identified. The master (missing) spline is another factor. The German VDM hubs often used a half depth spline that only mated with a master spline on the shaft. In this case, you show, the hub has a missing spline that must match with an extra wide spline on the shaft.
Difficult to know who has good info on this hub! I still think it may be Japanese, but it looks to definitely be an external counterweight early HS type copy / derivative.

Eng

 

[MiTasol]

A missing spline in a spider is unfortunately very common as many engines have one master spline on the prop shaft or have a locating screw which creates a master spline.

The example below shows the screw item 28 on a USAAF Merlin engine.

 

[Michael Hope]

Hi Larry!
Well, the inside of the spider looks to have cleaned-up. The rear opening for the propshaft looks to still have a large spring circlip retaining the rear cone or spacers. That could possibly be removed, those parts could have marks.
As far as the splines go, I feel that they may also hold the ID clues. Most national products used particular type and sized splines, and those look good enough to be accurately identified. The master (missing) spline is another factor. The German VDM hubs often used a half depth spline that only mated with a master spline on the shaft. In this case, you show, the hub has a missing spline that must match with an extra wide spline on the shaft.
Difficult to know who has good info on this hub! I still think it may be Japanese, but it looks to definitely be an external counterweight early HS type copy / derivative.

Eng

The snap ring is for the front cones with integral slot for a puller ring. The propeller piston/shaft nut would sit in the groove, and when the the piston is rotated to loosen it would pull the propeller off of the rear cone.

 

[Engineman]

The snap ring is for the front cones with integral slot for a puller ring. The propeller piston/shaft nut would sit in the groove, and when the the piston is rotated to loosen it would pull the propeller off of the rear cone.

Thanks Michael, got my front/back-to-front!
Just to ask, looking at the new posted pics on #60, you see the small dowel-pin on each of the 4 outside faces of the Spider, are those pins normal on a H-S 3 bladed spider for the early counterweight type?

Cheers

Eng

 

[cvairwerks]

Larry: Off the wall suggestion. Pull a copy of AN5017 and go to sheet 4. It's got a lot of the dimensions for splined shafts. Even though it's for fixed pitch hubs, the shaft info should be the same, as if I remember correctly, there were fixed pitch, solid hub test props available for almost every engine size during the war. If you can't get a copy, let me know. Unfortunately the file I have contains a bunch of fixed pitch prop stuff and is over 34 Mb.

 

[Engineman]

Here is a spec sheet I found on the internet. This might be a little small?

Eng

 

[Engineman]

Well, I think that I have clear evidence of a Japanese 4-bladed bracket prop! The picture is from "Japanese Aero-Engines 1910-1945" by Goodwin and Starkings. Page 107 shows this shot of a wrecked G4M2 with a Mitsubishi Kasei 21 MK4P engine and the front spinner missing, which shows the distinctive 4-blade H-S type Hub.

Cheers

Eng

 

[Michael Hope]

Thanks Michael, got my front/back-to-front!
Just to ask, looking at the new posted pics on #60, you see the small dowel-pin on each of the 4 outside faces of the Spider, are those pins normal on a H-S 3 bladed spider for the early counterweight type?

Cheers

Eng

I assume that those pins are for stopping the the thrust plate from rotating on the spider, similar to the two and three bladed spiders from Hamilton Standard.

 

[MiTasol]

Well, I think that I have clear evidence of a Japanese 4-bladed bracket prop! The picture is from "Japanese Aero-Engines 1910-1945" by Goodwin and Starkings. Page 107 shows this shot of a wrecked G4M2 with a Mitsubishi Kasei 21 MK4P engine and the front spinner missing, which shows the distinctive 4-blade H-S type Hub.

Cheers

Eng

View attachment 833151

Good one Eng.

I was about to say that, as far as I know, all German engines had flange drive not shaft drive so we could probably eliminate them and you solve the whole mystery.

Congratulations sir.

 

[Larrythepilot]

I am back to the 4-blade prop hub that we have never been able to positively identify. We think it is a Hamilton-Standard type prop, from a Japanese aircraft, but we don't know which specific model aircraft. We have never been able to find any numbers on the hub or the spider. ..... I'm posting here today because I have new information, WITH NUMBERS!! It turns out that we have the counterweights that we think go with that propeller, and the counterweights have a lot of clearly legible numbers, along with some inspection stamps. Do the numbers tell us which aircraft, or series of aircraft, used that propeller? Boy, I hope so. The 6 pictures are attached. Thanks for your help.

Larry

 

[Engineman]

Hi Larry!

Great to see you posting on this. I am afraid that all of my input has been based on observation of the parts and internet trawling, I do not have detailed info about the Japanese props.
However, I think that you can clearly see the Japanese stamps on these! Of course, the Japanese had a great many 3-bladed H-S type props, but I guess you have the set of four weights etc that go with this prop.

On another vein, I hope that you will get back to those VDM prop hubs soon? I will certainly be able to help more!

Cheers

Eng