Surface Propulsion, long-tail-emprovements.

Discussion in 'Surface Drives' started by tom kane, Feb 9, 2016.

  1. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Last edited: May 9, 2016
  2. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    https://youtu.be/nk2lPg6cpkE

    World`s best affordable Surface,Subsurface, Steerable, Retractable shaft drive for power boats. Very sophisticated or DIY project.
     
  3. Irie
    Joined: Jul 2016
    Posts: 62
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: Usa

    Irie Junior Member

    Has this drive been water tested?
     
  4. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    The principle of that drive and the U/V set up parts (one inch Prop shaft) has been used by me in a full size boat since 1960`s, with some big HP motors and I would not consider any other drive for the type of boating I wanted to do, mostly shallow and sheltered harbors and lots of sand bars and mud..for camping and fishing.

    But you can use the drive for high speed craft with adjustable shaft angle from the helm.

    Stern drives are to heavy and can not cope with lots of shallows and debris and mud.
    Jet drives are useless and suck up rubbish like a vacuum cleaner and just explode.Fixed shaft drive are not shallow water capable you get stuck with the shaft under the boat.

    Many different configurations have been tried and many ways a drive can be built for your own purposes from many varieties of materials. If you Google Pivotal Drive for boats or Cam.A.Propulsion for boats you can see some of the older models used.

    There are very sophisticated models possible to make boating a more enjoyable experience if you have the cash to build them.
     
  5. Irie
    Joined: Jul 2016
    Posts: 62
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: Usa

    Irie Junior Member

    I have been looking at all the information about your pivotal drive for a few months now. I really liked the idea of keeping the prop closer to the boat. My build ended up similar to your smart drive, with the shaft going thru the transom instead of the slot in the hull. I was just curious how it performed with the prop farther back. Because its an electric motor I simply made the motor mount trimable and steerable. So its a little bit long tail, a little short tail, and a little bit of your smart drive. I noticed on some of your variants the skeg extended under the prop, does this affect performance in any way?
     
  6. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    You don`t need a skeg if you want to take the risk of damaging your prop, which is a very good reason why I wanted a Pivotal Drive Retractable shaft as I once saw a new installed prop shaft and the trailer tilted and dropped down bending the new shaft moments after fitting.
    I don`t think a small skeg would give much drag.
    What is interesting is the number of ways you can build a shaft drive to propel a boat, there is no single way to do it or necessary plans to do it you can take many approaches to the design and different seals ect.,
    I like a small slot in the hull approach as you can get a flatter shaft angle which does not really matter as rake on the prop can give a flatter water flow.
    The slot acts as a strong transom post, when covered and fitted.
    You can fit the motor anywhere too. Googling Images Pivotal Drive for boats or Cam.a.propulsion for boats brings up a few of my diy experiments but of course I don`t show the more commercial ones.
     
  7. powerabout
    Joined: Nov 2007
    Posts: 2,901
    Likes: 61, Points: 48, Legacy Rep: 719
    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    That sounds interesting, do you have a photo?
     
  8. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

  9. brian eiland
    Joined: Jun 2002
    Posts: 4,788
    Likes: 157, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

  10. powerabout
    Joined: Nov 2007
    Posts: 2,901
    Likes: 61, Points: 48, Legacy Rep: 719
    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    Had that demo in trade school in oz 40 years ago but not with the thompson of course.
     
  11. brian eiland
    Joined: Jun 2002
    Posts: 4,788
    Likes: 157, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

  12. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Surface Propulsion, long-tail-emprovements

    Image shows twin universal joints with a sliding spline (a constant velocity joint believe it or not) 1938 Morris eight parts fitted to a motor (150 HP twin choke weber carburetor)and connected to a retractable shaft drive with a thrust bearing fitted to the propeller shaft.

    A shallow draft boat which could go anywhere the boat would float over mud and sand banks with out having to worry about the propeller as the skeg lifted the drive automatically in shallows and dropped down again in deeper water or you could lift the drive from the helm. The shaft and rudder and propeller lifted together as part of the retractable shaft drive.
    A great unit for any power for big or small boats.No need for a clutch as the prop could be lifted from the water.
     

    Attached Files:

    Last edited: Jul 21, 2016
  13. powerabout
    Joined: Nov 2007
    Posts: 2,901
    Likes: 61, Points: 48, Legacy Rep: 719
    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

  14. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member


  15. powerabout
    Joined: Nov 2007
    Posts: 2,901
    Likes: 61, Points: 48, Legacy Rep: 719
    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    2500 rpm max and not to be used as a daily driver.
    Doesnt sound like something that could be used in a boat
     
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.