Re: [electricboats] Electric Drive Installation - Some Data

I've just been testing a similar set up to Dan - same motor, ratio and feathering prop on a Jeaneau Gin Fizz

For the feathering I too could hear the shaft turning when under sail. My solution was to give a short burst of reverse on the prop and it feathers - rotation stops.

Keen to try out using the prop in turning mode under sail to see how much recharge power can be generated.

Will share more info on set up and results soon when I have a moment. In summary though very happy so far.

Great thread - thanks for publishing - will try to do my part!

Stewart

+33 6 87 96 66 80

On 25 Jul 2021, at 10:47, Carsten via groups.io <Carstensemail=yahoo.com@groups.io> wrote:



Dan, I envy you to just go for a sail !

For feathering, perhaps set sail, rev the motor up to 6 knots and set it to neutral. Then it should feather.

Does it begin to spin in short surges (unfeathers), if it is already feathered at higher speed, and you slow down ?

Another thing, when you tack, you can use the instantly available motor to keep up the speed, so it doesn't "die", when turning through the straight headwind. My boat dies easily in light winds, so I am looking forward to that.

Keep the motor running up to 6 knots, and set to neutral  for feathering. Just an idea.

If you want to check what's going on underneath, you could mount a Gopro with Wifi on a stick (aluminum tube), and see what happens on your smartphone :-)  See Youtube for connecting to wifi.

Also nice for checking growth.

When sailing, of course you'll need to secure the stick properly !

My MD6A Volvo idles at 600 rpm. 1100 seems a lot ?

You can use automotive hoses for the cooling system, and I think you already used that for the raw water ?

At the top inlet (the blue) hose of the controller, you can insert a valve to release the air trapped there.

Run the pump a bit when topping up, so it circulates.

Again, just an idea.

Carsten

On Sunday, 25 July 2021, 13:13:46 GMT+8, Dan Pfeiffer <dan@pfeiffer.net> wrote:

I have a little more info on props and performance in general.  I got out for an excellent sail today in 15-20 kts.  While sailing at a sustained 7.5 knots I checked the propeller and it was not spinning so it found its way to being feathered all on its own.  All I did was put the motor control to neutral.  At slower and more typical sailing speeds of 3-5 kts it seems to spin in short surges.  So there is more to learn about the prop behavior but it is able to fully feather and stay that way with more boat speed. 

And another thing about how the boat handles now compared to the diesel.   I can operate the electric at very slow speeds.  The diesel could not do that.  It idled at 1100 rpm which translated to 550 prop RPM and a bit better than 3 kts.  I can operated the electric at much slower RPM.  The steerage suffers greatly so it's debatable how useful that is but it is a distinct difference. 

Also I will need to upgrade the hoses I used for the cooling system.  They turn out to be rated for only to 65C and that isn't enough for high powered operation.  That's only 15C beyond the set point to turn on cooling.   I used Trident reinforced water hose.  I'll need something made as a heater hose.  The transparent hose was very handy in chasing bubbles out of the system.  But keeping the hoses from melting will be more useful. 

Dan Pfeiffer