Re: Electric Sailboat Ride
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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@...> 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@...> 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!? |