Controllable Pitch Propeller for lower power & electric motors

Discussion in 'Props' started by kistinie, Jan 2, 2010.

  1. thudpucker
    Joined: Jul 2007
    Posts: 885
    Likes: 31, Points: 0, Legacy Rep: 453
    Location: Al.

    thudpucker Senior Member

    I went back to Apex' initial post. I looked at all those links too.
    Two things popped up real quick.

    1. None of the brochures listed a CPP for small KW engines. I guess you'd have to contact each company to see what they had.
    2. Those are all European companies. No doubt they'd do business in the U.S. but you'd have to tell them so they could convert the Euro Brochure to U.S. or whatever.

    I don't know what a KW is when expressed in HP.

    On the optimum Blade details for a CPP. If the Slide rule came up with a Pitch/Dia figure for your craft, than the CPP blades should reflect that at full pitch. That's easy to understand.

    Another great value to a CPP is if the Calculation was wrong, you just change the blades instead of the whole prop.

    Going back to my 24' with twin 140's it didnt seem to need CPP's or I was ignorant to the need.
    But my commercial fishing boat, a 29' with a single 327 Chev sure could have used that CPP.

    For acceleration with a big load and limited HP, that CPP could save you a lot of money over time.
     
  2. Submarine Tom

    Submarine Tom Previous Member

    thudpucker,

    About 750 watts (0.75kw) = 1 HP

    -Tom
     
  3. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Die welle

    Your CCP autocracy world is a fun world, where engine must be above 50 kw to exist, and are respected if above 10 tons, where Electric motor are useless, and alternative experience a nonsense...What a strange wave breaking in this forum.

    An electric motor needs a CPP if pole number is not enough to do the speed reduction through electric pole division.

    A 12 pair of coil connected on 3 phases with 14 magnetic poles fed, with 50 Hz is 250 Tr/mm
    As standard Controllers and motors have a limit frequency usually around 40kHz for all poles that injected to 12/14 motor will give us a max around 3000 Tr/mm, with a safe half of it, then, that is OK for not using a CPP

    But most of electric motor are less than 12 poles, rather 8, so they need reduction and CPP to perform well

    Please also understand that our near future is electric and lower power, just like it is already the case for race sailing boats.

    Now relax, go to kino and watch "Die Welle", may be you will understand.

    I am so cool with the neg rep i have, i even can correlate it with negative entropy of magnetism, so please give me some more - rep, a lot !! To save €€ on oil, gearbox and other CPP dinosaurs !!!
    Kiss...tiny....bad boy...APE EX !
     
  4. apex1

    apex1 Guest

    The optimum blade for the CPP is the one coming with it! You must not change it because it cannot be wrong.
    The given diameter dictates what the optimum is. When your engine can turn a 50 cm wheel, then that is the one you have to live with, is it 70 cm, well better so. The pitch is adjusted by YOU over the complete range and it is always "optimal" if you adjust it according to the engine load.
     
  5. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Right this is the same for EM : A Big prop diameter allows to avoid CPP but of course with the drawback of not accelerating as well as with a CPP. Regen will be less efficient too on high and low speeds.

    To drive a large prop, the EM must be able to manage, efficiently, very low speeds like 100 Rpm.

    Then no more CPP needed, and nobody gets hurt, as nothing was available :)
     
  6. apex1

    apex1 Guest

    Wrong as usual. Unwilling or unable to learn................
     
  7. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Learn what ?

    Learn this ? http://www.boatdesign.net/gallery/showphoto.php/photo/13516/ppuser/11121

    72 feets, 34 knots light:p ship (40 tons of Mahogany)


    No, i am very sorry APEX, I will not learn from you equation 72" 40 Tons, 34Knots...before antigravitation and overunity motors are available !
    Of course, equipped this way your boats will be real beauties, and no more, just another nice expensive boat respecting close nothing
    I understand you do not like reading this as you seem to make efforts to do good job, but i will not change the matter and magnetism physics for your blue yes.

    Speed and weight is not compatible unless you respect nothing. Speed+weight is too much energy, too much drawback for the rest of mankind. This is a maths and physic rule.
    Not powering your boat with light electric solutions is just like having a toilet in the kitchen.

    Doing the effort to lighten more and use smart light power group, will make your boat more homogeneous.
    Now the question of what is sold, what user want to pay for is another thing, an education thing again !
     
  8. PetterM
    Joined: Sep 2004
    Posts: 211
    Likes: 9, Points: 28, Legacy Rep: 201
    Location: Norway

    PetterM Senior Member

  9. apex1

    apex1 Guest

  10. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    Thanks for links Petter, do you know if the Sabb HPV15 is 43Kg with all accessories and the drive line ?
    Very smart efficient drive.

    What is total weight of a CPP line including or not the blades ?
    An idea of the price of the full line ?

    About servo, the blade design and architecture looks smart. Market is down-sizing HP for more economy on fuel, They could think of smaller versions using the same technology.
     
  11. PetterM
    Joined: Sep 2004
    Posts: 211
    Likes: 9, Points: 28, Legacy Rep: 201
    Location: Norway

    PetterM Senior Member

  12. PetterM
    Joined: Sep 2004
    Posts: 211
    Likes: 9, Points: 28, Legacy Rep: 201
    Location: Norway

    PetterM Senior Member

  13. PetterM
    Joined: Sep 2004
    Posts: 211
    Likes: 9, Points: 28, Legacy Rep: 201
    Location: Norway

    PetterM Senior Member

    there has also been a few variable pitch surface drives made over the years:

    Yellowfin VSD (made quite a few non commercial units, but never made it into production)
    FRANCE HELICES (only made one?)
    Servogear AS (made one installed on a patrol boat in Norway)
    CPS- Drive (made two test units installed on one specially designed catamaran in Norway)
    Stormfagel (still going, only one made so far in Sweden)
    Escher Wyss (7 blades, used on a SES in Norway, don’t know of any other installations)
    Have I missed any out?
     
  14. gonzo
    Joined: Aug 2002
    Posts: 15,617
    Likes: 1,107, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Kristinie seems to think that someone has to manufacture CPP's at a loss to satisfy his wants.
     

  15. kistinie
    Joined: Aug 2007
    Posts: 493
    Likes: 8, Points: 0, Legacy Rep: -74
    Location: france

    kistinie Hybrid corsair

    No for my use, i refuse all these heavy and expensive devices.
    An electric pod is so much easier and lighter device, just ONE moving part.


    But low power CPP, included to an hybrid prop group could give an acceptable cost solution, very reliable and efficient.
    CPP function included to the engine by factory would be an affordable over cost.

    i bet that in less than 2 years this will be available on under 50Kw engines

    And dear GONZOB take care you do a recurrent mistake. Kistinie is not from "Kristrian" but from Kiss !
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.