Propeller pitch adjusters

matspart3 · Jun 12, 2020

Now reimagined as candle holders but can you identify what they're from?

Michael Hope · Jun 13, 2020

The appear to be the cams from a Hydromatic type propeller. I do not think they are Hamilton Standard because there are no gear teeth on the bottom of them and they had more lightening holes between the cam slots. They could be De Haviland or other copy of the method for pitch change.

Tom Fey · Jun 18, 2020

Hamilton Standard Propellers

Michael Hope · Jun 18, 2020

This an image of Hamilton Standard pitch change cams for a 23E50 type propeller, taken from the Hamilton Standard Illustrated Parts Catalog 143. The cams in the original post do not show have the required hole for the cotter pin to keep the cam nut locked in place. Plus the Hamilton Standard cams have more lightening holes to reduce weight. Also the outer cam has a different dome shelf with a different hole arrangement. This is why I believe that these would be a copy of the Hamilton Standard Hydromatic type not a genuine item.

MiTasol · Jun 19, 2020

Michael Hope said:
This an image of Hamilton Standard pitch change cams for a 23E50 type propeller, taken from the Hamilton Standard Illustrated Parts Catalog 143. The cams in the original post do not show have the required hole for the cotter pin to keep the cam nut locked in place. Plus the Hamilton Standard cams have more lightening holes to reduce weight. Also the outer cam has a different dome shelf with a different hole arrangement. This is why I believe that these would be a copy of the Hamilton Standard Hydromatic type not a genuine item.

The cam profiles are also different from those shown in your diagram however I would suggest that they could well be genuine HS parts as there were a lot of variations to the 23E50 series between the mid 30's when they first developed and the late 60's?? when the last versions were produced for aircraft like the DHC Caribou.

Some were constant speed and non feathering, some added feathering, some had quick feathering, some added reversing, all of which would require different cams and other internal variations.

Add to that the variations for the D, EX and F shaft engines and there are probably over a hundred different cams from HS alone, without getting into the dH and other licence built variants.

If my rusty memory is correct some of the cam nuts were locked by grub screws.

nuuumannn · Jun 19, 2020

Michael Hope said:
The appear to be the cams from a Hydromatic type propeller. I do not think they are Hamilton Standard

Just a wee bit of a note, the term "Hydromatic" was a Hamilton Standard brand name patented by the company, so only Ham Std and its licence built off shoots could use the term. It does describe the actuation of the pitch change mechanism by differential oil pressure against a piston, but the name is strictly an HS brand name.

The candle holders are probably from an HS prop, but they look smaller than the 23E50, of which the diagram is from.

MiTasol · Jun 19, 2020

nuuumannn said:
The candle holders are probably from an HS prop, but they look smaller than the 23E50, of which the diagram is from.

They look D shaft to me also but I cannot think of a reversing D shaft HS installation and I am fairly sure that cam profile is feathering and reversing. With no dimensions tho we are both guessing unfortunately.

Off the top of my head the only D shaft feathering prop I can think of is the 22D30 on the Beech 18/C-45 series. Unless the Volpar conversion had reversing props I doubt any of that series had them.

Michael Hope · Jun 19, 2020

MiTasol said:
They look D shaft to me also but I cannot think of a reversing D shaft HS installation and I am fairly sure that cam profile is feathering and reversing. With no dimensions tho we are both guessing unfortunately.

Off the top of my head the only D shaft feathering prop I can think of is the 22D30 on the Beech 18/C-45 series. Unless the Volpar conversion had reversing props I doubt any of that series had them.

The 22D30 and 22D40 Cams had a row of ball bearings holding the cams together so these are not those, so no threads.
The D shank propellers did have reversing features, in the 43D50 and 43D60 series propellers series. The size of the cams was the same as the domes were the same size, so the cams were the same size. Aircraft in Canada that did use them were the DHC-4 Cariboo, and the Canadair DC-4M and C-5.

MiTasol · Jun 19, 2020

Michael Hope said:
The 22D30 and 22D40 Cams had a row of ball bearings holding the cams together so these are not those, so no threads.
The D shank propellers did have reversing features, in the 43D50 and 43D60 series propellers series. The size of the cams was the same as the domes were the same size, so the cams were the same size. Aircraft in Canada that did use them were the DHC-4 Cariboo, and the Canadair DC-4M and C-5.

Thanks. I thought the DC-4M would have used 23EX spiders and hubs like the Canadian Hurricane and Lanc and I was surprised they used D hubs.

nuuumannn · Jun 20, 2020

They're not from a Caribou prop; it has the teeth on the inner cam and larger flanged section on the outer (I have a Caribou prop cam in my garden and just went to take a look).

Propeller pitch adjusters

More options

matspart3

Recruit

Attachments

Michael Hope

Airman 1st Class

Tom Fey

Airman 1st Class

Michael Hope

Airman 1st Class

MiTasol

1st Lieutenant

nuuumannn

Major

MiTasol

1st Lieutenant

Michael Hope

Airman 1st Class

MiTasol

1st Lieutenant

nuuumannn

Major

Users who are viewing this thread

Similar threads