Mechanical reversable pitch prop for small boats.

[thudpucker]

One of you old guys will probably come up with this one.
In the 50's I used to rent a skiff that had an air cooled 5 Hp (Briggs?) and a shaft drive to a Mechanically reversable pitch prop.

Is there any prints or pubs on that kind of a thing any more?

I'm still thinking of my little Jon boat and still doodling over the power and propulsion possibilities.

Maybe Air or Hydraulic?

[ancient kayaker]

Way back there was the WaterMota sailing/reversing propeller, which could also be feathered, but Sheridan marine advised me it is no longer available and neither are parts. Here's a pic - http://www.boatdesign.net/forums/att...brochure_1.jpg

[kistinie]

Or this is a simple VPP solution for power under 10Kw, just like the one i'm searching for my electric motor ?

How do you explain this product disappear ?

[thudpucker]

Thanks Terry. Thats very similar to what I recall.
I'll have to dream up and invent in my mind to figure that one out.
I saw another one that had a second shaft going through the stern. That second shaft rotated the prop blades by a roller in a slot as they went around.

Kintinie I'd bet the advent of outboards caused the demise of the water mota, the Dippy and a lot of those early propulsion inventions.

I use Maxprop that is a similar product. Nautor installs that too.
http://www.boattec.de/verstellpropp.htm

Kistinie "How do you explain this product disappear ?" What a question.
How do YOU explain that "Simca" went out of production? An btw. the acronym is CPP

[kistinie]

CPP ! yes your right ! i mix french and english, sorry !

Simca was nothing very special and tech was kept by Matra and Panhard still producing cars and military awd amphibian trucks

Max prop, autoprop and other j prop or flexoprop are not real CPP you can control as you like ?

I really think CPP for small power could be the perfect solution in an electric prop/regen/sail solution.

Following discussion i had with french manufacturers It seems that new CPP products are close to be produced again for these applications but it is difficult to find information about this...Keep your secret secret seems to be true not only for 007, also in propeller world !

[ancient kayaker]

Originally Posted by thudpucker

... I'd bet the advent of outboards caused the demise of the water mota, the Dippy and a lot of those early propulsion inventions.

The dispro enthusiasts have preserved hundreds of those classic boats and parts are still available more than 50 years after they stopped manufacture. Dozens of these boats show up at the regattas every year. However, the motors are about as reliable as Lucas ignition systems but they seem to enjoy towing each other back to the dock. Hee's the website: I find the name singularly appropriate
http://www.dippy.ca/
Every time I see one I am always just a little bit disappointed it isn't driven by steam.

[kistinie]

Coming back to CPP
Here is an interesting study

http://www.kastenmarine.com/CPprops.htm

Of course, it remains to the good idea level as there is nothing for most of us, that is to say, nothing under xxxKW engine

[thudpucker]

Here's my thoughts.
The one I rented back in 52-53 had a shaft driving the prop hub.
The Hub had two studs or extensions sticking out perpindicular to the shaft.

On the Studs were two blades which could rotate freely all the way around.

The blades had an extension (fwd) that rode in a raceway.
The raceway slide fore n' aft on the prop shaft.
The extension of the prop blades rode in the Raceway.
If the Race way went aft, the blades were rotated to catch water and throw it forward.
Race way rotated Fwd, the blades caught water and propelled the boat fwd.

This must have been water lubed. I recall the whole thing was noisy but it workded.
The little motor had a 'kick starter' you stomped down on to start the motor.
Simple and effective.

The newer CPP's are all internally geared, with a shaft inside a shaft. Making them expensive and probably heavier than the stuff I remember.

I should have put that info up in the first post. I really didnt know there were as many CPP's out there untill you guys came posting.