360 rotate sail drive

Hi, Can anyone point towards a thread to do with 360 docking. I'm thinking of having a sail drive on a pontoon boat run from an Agni Lynch motor and would like it to be able to rotate 360 degrees for docking. Has anyone discussed this or have any experience... Thanks

 

A full 360 degree rotation causes some unique engineering issues. Can you define the vessel's needs a bit better?

A sail drive isn't the best choice for your pancake motor. You're just dragging around gear sets, raw water pump, possibly exhaust plumbing, for no good reason, all detracting from efficiency.

 

At least one commercial version with similar ambitions from Mastervolt -

http://www.mastervolt.com/press-releases/the-new-podmaster-from-mastervolt/

 

The motor is 11kg and to my knowledge doesn't need anything else. The use is docking when past it's usual direction otherwise slow cruising on a canal. Thanks

 

I came across this: Whisperdrive, though I don't know if it does 360deg.

 

Yeah thanks, I'd seen that one, I was wondering how effective it would be on my cat, only for docking sideways and diagonally slowly, the rest of the time as normal

 

I've only seen one WisperDrive and it was a fixed mount.

Again, what are the parameters for this requirement (boat size, weight, etc.) as parking a typical pontoon boat isn't especially difficult. Skidding one dead sideways can work with a more conventional approach (dropping in a trolling motor for example), while a main drive system handles the propulsion chores. Seems a simpler, cheaper way to go then cobbling together an assembly of parts, not well suited for each other.

 

Yeah same pontoon boat, as you say not particularly difficult. If I'm designing I don't want to be dropping other motors in, I want the main drive to do the lot really. The propellor shaft and Agni/lynch motor will be rated to each other accurate design is what I'm planning.

 

Azimuth thrusters have been around since the 60's used on The Queen Mary in case anyone is interested

http://en.wikipedia.org/wiki/Azimuth_thruster

 

It's not that it can't be done, but it is to say the engineering problems are significant and current retail applications/products aren't especially cheap.

The easiest route is a submersed motor, mounted on a shaft, with it's shaft horizontal, like a trolling motor. This places the motor in a place it can be continuously cooled, the shaft is in alignment with desired thrust vector and the shaft mount will permit 360 degree rotation. Personally, I think the 360 degree rotation aspect a limiting factor, when 270 degrees could be easily achieved and would solve sideways handling issues. Of course, mounting a pancake motor of this size, isn't the best route for a prop, but if this is what you have. Adding a 90 degree gear set could reduce a considerable amount of shadow, before the prop, but you'll have some loses with this arrangement. Maybe a flexible shaft setup should be looked at.

 

Wow sounds ambitious, I'm looking at the Voith azimuth system. I suppose a prop shaft with the motor in board might be safer all round if it gets damaged or snagged....

 

I have used azimuthing thrusters and propulsion on numerous commercial vessels, mostly tugs, but some DP vessels as well.
Some advantages are: no reverse gears and the propeller doesn't loose efficiency operating in reverse.
As to maneuverability with a single thruster, azimuthing doesn't help that much. But with twin azimuthing thrusters, and some skill in handling them, you can maneuver the boat into any space big enough for the boat.

 

Thanks, so one is no use or two is much better, I mean even with an outboard you can get manoeuvrability and so I've been told dropping one on the side of the boat will even move it sideways ?

 

http://rotorque-jet.de/

These retractable rimdrive hubless prop units might interest you. Integral electric motor is in the rim.

http://www.youtube.com/watch?feature=player_detailpage&v=2MySHd2UduY

 

But don't forget the dinghy.

http://www.youtube.com/watch?feature=player_detailpage&v=7D020Igd0j0