Controlable Pitch Prop

Discussion in 'Boat Design' started by viking north, Apr 20, 2014.

  1. Busteddrum
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    Busteddrum New Member

    Other benefits to CPP

    Hi All. Am new to this forum and find this thread very interesting. I bought a Hundestead CPP to use with a ZF reversing marine gear and a Gardner 5lw engine on a 60' sailboat. The boat has been sold and I still have the engine/drive.

    I have read the two most recent lengthy threads discussing CPPs and did not see reference to some other benefits. Sorry if this repeats other posts.

    Power in reverse can be had at a very fine pitch to minimize prop walk until speed is achieved for rudder control. Same to a lesser degree forward because of using thrust against the rudder for directional control.

    With a reversing marine gear the blades can be placed in the feathered position and be used as a stern thruster, pivoting within a boat length, the direction dictated by gear chosen.

    If close quarters maneuvering is a concern and the cost of a bow thruster can be applied to the drive budget instead, then the added benefits of proper engine loading, blade feathering, and the ability to accommodate varying conditions and loads are cost neutral. Another benefit is that the huge hole in the bow (and it's inherent drag)is avoided. I would rather change oil in the gearbox and grease the hub of a CPP at haul out, than dive the thruster tube, wheel, and drive for cleaning.

    If the wind speed and direction never changed, the ocean was always flat, and the boat load was always the same, then a fixed prop would be more efficient at one speed only.

    These were the final selling points for me. YMMV.
     
  2. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Oh, Viking. By the way. That 2 cylinder Volvo engine in the Albin Vega? (Shhh. it's an Albin motor.)

    I have the 3 cylinder Albin diesel orginal to one of my two Albin 25s.

    I bought a 2 cylinder Volvo running take out from an Albin Vega.

    Same engine, just a bit smaller. Many parts interchangeable.

    Albin sold their motor design to Volvo and continued making engines in the Albin plant, but with a Volvo label. These are GREAT engines. even the valve cover is cast iron. Real fuel sippers and REAL horses, not ponies like high speed diesels. seemingly last forever.

    http://www.albinbc.com/home/albin-25-history
    "Early 25s had a 20hp diesel built by Albin themselves (the company originally manufactured some of the smaller models in the Volvo range). This engine was a touch underpowered, giving a top speed of just over eight knots, so in 1971 the builders switched to the 36hp Volvo MD3B, which lifted the speed to around ten knots, depending on load. In 1975 the MD3B was replaced by the similarly rated MD17C, which became the standard engine for the rest of the boat's production life. The Albin 25 might not win any races, but she won't bankrupt the owner either: at nine knots, with an average load, she will use about 1 1/2 gph. "

    The 3 cyl and 2 cyl Albin motors burn less than half gallon per hour.
     
  3. Yobarnacle
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    Yobarnacle Senior Member holding true course

  4. viking north
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    viking north VINLAND

    BD, a Gardner and a Hundested what a combo, doesn't come better. You must have been driving a 3 blade prop in the range of 20 to 24in. If I was a younger man with a larger boat I'd be hounding you to purchase that package. :D Never thought about the side thrust before, a true paddle wheel. Simply nose the boat to the dock, tie on a bow line and paddle her stern around. Don't happen to have a smaller 3 blade CPP system suitable for the 30hp., 16in. to 18in. dia.blade range kicking around :). I've contacted 4 possible manufacturers thus far, one is a definite no three no response. I am also trying to contact the owner of a used one in Finland that TeddyDiver referred to but having language problems. However TD thinks this unit does not feather. The search continues --

    A yacht is not defined by the vessel but by the care and love of her owner --
     
  5. viking north
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    viking north VINLAND

    Hey Yo -- you got STUFF tucked away :D. I was under the impression you had only electric motors. I like STUFF -- AHhhhhh I should have delayed my return North for another couple of weeks or so but I was just so dam exhausted hunting down boat parts from Fort Pierce Surplus to SailorMan to St Petes Surplus. Ended up back to where I started and lucked in on some great buys at the Marine Surplus in Daytona. They just had a new shipment of new and used goods arrive. If I was younger and could get a Greenie, Daytona would be my Paradise -- Great Town for Boats--Motorcycles and Jeeps. I say no more :D
     
  6. Jeremy Harris
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    Jeremy Harris Senior Member

    Reading this thread reminded me that I had an old CPP sat out in my workshop, gathering dust. Been there for at least 20 years, IIRC it came from a small four stroke air cooled petrol motor, something like a Briggs and Stratton, that had no gearbox or reversing gear, just a lever that operated a bearing on the outer prop shaft sleeve to move it forwards and back to change the pitch and direction. The solid inner propshaft sleeve was coupled solidly to the engine crankshaft, so the prop turned all the time the engine was running (a bit like the old Seagull outboard I used to have years ago).

    The prop still seems to work fine, I pushed the outer sleeve in and out and it changes pitch like a dream. Probably not been moved in at least 20 years, but being made of solid bronze there's nothing much to go wrong with it.

    I may have a play with it on a small boat and see how it works. it's about 12" diameter, I've no idea what the max pitch is in either direction, at a guess at least 12".

    I wish I could remember who made these things, they were quite popular here around 30 or 40 years ago. I've probably owned it for at least 30 years, as I am pretty sure that I was originally going to use it in the first boat I restored, an old 20ft gaff cutter, back in the very early eighties. This prop was old then, mind.

    Here's some photos I've just taken, might jog some memories:
     

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  7. viking north
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    viking north VINLAND

    Jeremy -- a nice piece of kit. The fun you could have with that and a small gas,diesel or electric. I think there has been good CPP activity on this thread, lets keep it going to show some small manufacturer sitting in the wings, there is a market for these units in the smaller and medium engine power range. And by all means dig one up for my build :D
     
  8. MoePorter
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    MoePorter Junior Member

    Thanks, Busteddrum-
    New idea for me & it's something I won't forget. Nothing like adding another 180 degrees of motion to a piece of gear I thought was only good for Forth & Back...and for free. I like it! Moe
     
  9. pdwiley
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    pdwiley Senior Member

    I don't suppose I could convince you to take it apart, photograph (and preferably measure) all the bits, and post the details here, could I?

    Please....

    I have a machine shop and access (for money) to a foundry. I'd like someone to pull down a Sabb 30 HP unit but failing that, I'll take anything I can get WRT CPP details.

    PDW
     
  10. viking north
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    viking north VINLAND

    PDW --I haven't forgotten your request from posts back -- was waiting to hear from a couple of the old makers to see if they would sell their plans or offer them for manufacture under license. So far no replys but maybe they are thinking it over. This is a detail set of dimensions from Hundested that might be of general interest. --Geo.
     

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  11. pdwiley
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    pdwiley Senior Member

    Thanks for that, I'll add it to my collection of information.

    I'd like to get the current boat finished and have time to play with it before doing anything else but if one has the information, one only needs to find the time and the materials. There's not much in this size range that I can't make if I want to badly enough. Some time ago I bought a pottery kiln with the thought of using it to melt aluminium & bronze for doing my own castings and I already have all the machine tools I need. Well more or less - I still need (want) a small horizontal boring mill....

    PDW
     
  12. Yobarnacle
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    Yobarnacle Senior Member holding true course

    WELL..... I just happen t have the CP gearbox still attached to the Volvo-(Albin) 11 hp 2 cyl diesel. Frozen up but I need to take it off anyway. I'm planning to use the engine to drive generators.

    Jeremy, shipping to UK is prohibitive.

    PD or Viking, any interest in the Vega CP gear box?
     
  13. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Earlier I said I had a 2 cyl and 3 cyl Albin diesel. Error! I have a ONE cyl and a 2 cyl engine.

    The MD1 Volvo is listed various places as developing 9, 10, and 11 hp.

    The CP unit is mounted on the 1 cyl MD1.

    The Albin Vega also was produced with a 12hp gas engine installed.

    All this unsolicited info, is relevant to the CP transmission I'm not needing.
     

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  14. pdwiley
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    pdwiley Senior Member

    I'm in Australia so I doubt the shipping to me is any better than to Jeremy. Also I'm not sure what use the g/box without the shaft assembly and prop is going to be. If you mean all of the above, that's different. I'd definitely be interested but the freight is still the issue..... costs me $100 to get a pair of sheet winches posted from Florida to Australia.

    So it'd be better going to Viking, I'm sorry to say.

    PDW
     

  15. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Thanks for responding. Guess I'm getting old and memory failing. Was thinking Hobart in Canada. DUH!

    I only have the controller. The Vega owner I bought the engine from, kept the prop and shaft and they remain installed in boat. They are using a gas outboard now.

    The diesel I bought runs perfectly. I had a diesel mech check it out.
    People are amazing and often illogical.
    I'm often amazed at the decisions I MYSELF make!
     
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