Monday, May 10, 2021

Re: [electricboats] Electric Sailboat Ride

Do you need to lock the prop shaft to get the Autoprop to feather for sailing?   If so how do you plan to do that? 

What motor is that?  Looks like a Thoosa?  Is there a thrust bearing in the motor?  

Do you have any performance data to share?  Knots vs Watts? 


Thanks, Dan Pfeiffer

 



On 2021-05-10 10:30 am, Matt Foley wrote:

Hi Ken,
 
Yes, and according to the manufacturer it should perform better than a fixed prop. I was getting about 22 watts at 3.8 knots. Haven't had any real wind for testing yet. Hopefully this week. There is only so much power we can expect to generate at typical sailing speed for a 30' mono and a limited swept area so I'm not expecting miracles, but hopefully it will be close to as good as it can be.  
 
Matt Foley 
Sunlight Conversions
Perpetual Energy, LLC
201-914-0466
 
 
 
On Monday, May 10, 2021, 11:18:58 AM EDT, Ken Winokur <kenwphoto@gmail.com> wrote:
 
 
Hi Matt
 
Very interesting. I'm a broker and I have sold several boat with Diesel engines and Autoprops and am well aware of their advantage. I was unsure how they would translate to electric drive. Are you able to  regenerate power with the autoprop? 
 
K

On Mon, May 10, 2021 at 11:10 AM Matt Foley <matt@sunlightconversions.com> wrote:
Hi Ken,
 
 I use my own boat for testing. I'll try and write it all up one day with specs and measurements, but briefly. 
 
I started out at one extreme with a tiny 12' low pitch prop. This gave me a high RPM which allowed for direct drive. Efficiency at lower speeds were ok,  got worse the faster I went and struggled to hit 5.5 knots. Even so I was happy enough with it's performance. 
 
I'm now using a 16.5" Autprop and a 2:1 reduction. I have only done a few quick test runs, but it's a huge improvement. I would say at least 30% efficiency improvements and I can hit 6.5 knots with ease. 6.7 knots is theoretical hull speed. I will be moving up to a little over 3:1 reduction which should improve system efficiency a bit more. 
 
What makes the Autoprop unique is the ability for the blades to automatically adjust themselves to provide the most thrust at any RPM. This means lower RPM's for any given speed. All things being equal, a lower RPM prop will always be more efficient. Paired with the right motor and or gearing this will be a very efficient setup.  They also pitch themselves to provide maximum regen! (yet to be tested) 
 
Two additional benefits (which I'm less concerned with). They improve sailing speed when not regenerating and you get 100% reverse thrust. 
 
 
Matt Foley 
Sunlight Conversions
Perpetual Energy, LLC
201-914-0466
 
 
 
On Monday, May 10, 2021, 09:59:18 AM EDT, Ken Winokur <kenwphoto@gmail.com> wrote:
 
 
Very interested in your autoprop and why you chose it. Tell us more about it please.

On Sun, May 9, 2021 at 11:53 PM Matt Foley <matt@sunlightconversions.com> wrote:
Anyone interested in learning more about an electric boat or just want to check one out. You are invited for a sail anytime. Just bring the beer! 

Boat is located in Atlantic Highlands, NJ.

O'day 31
8.1kw brushless motor
10.2kwh lifepo4 
Orion JR BMS 
Brunton Autoprop
460 watts solar (custom carbon fiber solar bimini in the works)

Also have a converted Honda 2.3 on the dinghy

Matt Foley 
Sunlight Conversions
Perpetual Energy, LLC
201-914-0466
 

 

 



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