Re: [electricboats] Epropulsion Navy 3.0 Propeller Dimensions

I'd recommend looking at what has been done for propeller-driven pedal-power drives.  Model airplane style propellers have been used effectively for these to drive kayaks at around 10kts.  This one by Bob Stuart is about as efficient as they've been made:

https://microship.com/bob-stuart/

There's even a picture here of a pedal-powered kayak (aka "Kawak") pulling someone on skis…crazy Canadians.

http://lampi.us/mike/boating.html

Also check out the old IHPVA link at the bottom of that page.

Here's a 1981 IHPVA issue where the design of the "Decavitator" hydrofoil design is detailed:

http://www.ihpva.org/HParchive/PDF/31-v9n3-1991.pdf

 

 

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Keith M
Sent: Sunday, January 12, 2020 5:37 AM
To: electricboats@groups.io
Subject: [electricboats] Epropulsion Navy 3.0 Propeller Dimensions

 

I would like to retrofit a higher pitch propeller on my 86# thrust trolling motor for a light weight (165# hull) semi-planing boat that is designed to go about 2X hull speed with very low thrust.  I have seen reference to the RC plane pusher props, but I am not convinced that the surface area and strength is robust enough for water applications.  The Navy 3.0 two bladed propeller, N3-LU05-00, is within 0.1" of the diameter of my trolling motor and probably a little more than twice the pitch (10.2 × 6.73 inch).  The trolling motor RPM is 1,800 with no load, which is 500 less than the Navy 3.0 specification.  Examing the pictures, it looks like a good candidate.  Prior to spending the $50 plus shipping, it would be helpful to know if the propeller will fit.  The key measurements are the maximum hub diameter, shaft diameter, and the shaft length inside the hub from the pin to the front face.  I am also interested in alternative solutions or ideas...

The trolling motor is a brushed DC motor, so I believe there is no change in performance for clockwise vs counterclockwise rotation.  The wires are easily reversed on the output of the speed selector switch and the speed resistors are not sensitive to polarity.  I will also compare the current draw with the stock propeller vs the retrofitted propeller to prevent damage to the trolling motor.