A re-think about electric outboards

[sarabande]

With Torqueedo costing far too much, and Bisons apparently melting or corroding in minutes, I wonder why designers try to imitate the format of the 'normal' outboard, and use props.

I have an electric 240v pump to squirt water along 50m of 45mm pipe. The output seems to be well up to pushing my hand hard away, and the motor is rated at 1.9kW. The pump bit is a centrifugal one.

Would it be worth me chatting to our local steel fabricator to build a 12v version of the pump, arranged so that the suction and squirty sections replace the prop and gearbox bits on an old outboard, with the motor where the old IC engine was.

I don't want huge range or high speed, just quiet, and lightish to carry. I do like the near 100% ability of an electric motor to work when 0 turns to 1.


Loads of examples on youtube...

 

[richardabeattie]

You'd need good filters on the water intake and perhaps a second intake for when the first bungs up.

 

[Bouba]

There are electric jet skis, have seen them in hire centres. It’s the same principle with electric vehicles, the most popular ones look like ordinary cars. Perhaps as a species we prefer evolution

 

[rogerthebodger]

With Torqueedo costing far too much, and Bisons apparently melting or corroding in minutes, I wonder why designers try to imitate the format of the 'normal' outboard, and use props.

I have an electric 240v pump to squirt water along 50m of 45mm pipe. The output seems to be well up to pushing my hand hard away, and the motor is rated at 1.9kW. The pump bit is a centrifugal one.

Would it be worth me chatting to our local steel fabricator to build a 12v version of the pump, arranged so that the suction and squirty sections replace the prop and gearbox bits on an old outboard, with the motor where the old IC engine was.

I don't want huge range or high speed, just quiet, and lightish to carry. I do like the near 100% ability of an electric motor to work when 0 turns to 1.


Loads of examples on youtube...

Because the efficiency of converting the thrust from a convertible pump/nozzle in to thrust to propel a boat is so low its unusable.

Look at a all bow thrusters and jet boats they are low pressure high volume pump (axial flow turbine) as is a propellor.

Th guy who started vetus cane out with a pump /nozzle based thruster and it proven to be no very effective.

 

[coopec]

There are articles comparing the efficiency of jet vs prop and the jet holds it's own in certain situations.

Every thing is going battery powered these days: they are testing battery powered farm tractors and mine dump trucks.

 

[rogerthebodger]

There are articles comparing the efficiency of jet vs prop and the jet holds it's own in certain situations.

Every thing is going battery powered these days: they are testing battery powered farm tractors and mine dump trucks.

A jet boat is effectively a ducted propellor (axial flow propellor)

 

[JumbleDuck]

 

[Jabs]

With Torqueedo costing far too much, and Bisons apparently melting or corroding in minutes, I wonder why designers try to imitate the format of the 'normal' outboard, and use props.

I have an electric 240v pump to squirt water along 50m of 45mm pipe. The output seems to be well up to pushing my hand hard away, and the motor is rated at 1.9kW. The pump bit is a centrifugal one.

Would it be worth me chatting to our local steel fabricator to build a 12v version of the pump, arranged so that the suction and squirty sections replace the prop and gearbox bits on an old outboard, with the motor where the old IC engine was.

I don't want huge range or high speed, just quiet, and lightish to carry. I do like the near 100% ability of an electric motor to work when 0 turns to 1.


Loads of examples on youtube...

That is 118 amps at 12v DC, assuming 100% efficiency. The judged weight should include the weight of the battery!

Quite a motor and a huge battery if you want any range.

Tony.