T-Pain Is On A Boat: Re: [Electric Boats] propeller direction

Hi Bill.
The right hand rotation props are more common and cheaper to replace when damaged as well as being often in stock for shipment. I tried a 12 x 8 two blade on my electric and was bothered by vibration. A 12 x 13 three blade was far smoother. Check that you have sufficient tip clearance from the hull, deadwood and rudder. ie roughly 20% of the prop diameter, about 2.4 inches minimum for a 12 inch prop. Too close will cause rebound vibration between the hull and prop that is often not noticed with a noisy ICE originally installed. I have also found a 3 blade to be far better in reverse than a 2 blade. Also an 11 x 13 with 3 blades might have a lot less vibration because of separation from the hull being more and also give more torque for rough conditions.
On a previous boat a 2 blade Minn-Kota could not reverse into a 10 mph wind while a 3 blade Motor-Guide prop modified to fit the same Minn-Kota motor was able to reverse into a 20 mph wind slowly. Speed in forward was virtually identical with both props.
Hope this is helpful.
Dave on "Day Dream Believer"

--- On Sat, 11/6/10, Bill Spires <spiresac@yahoo.com> wrote:

From: Bill Spires <spiresac@yahoo.com>
Subject: Re: [Electric Boats] propeller direction
To: electricboats@yahoogroups.com
Received: Saturday, November 6, 2010, 7:05 PM

What is your set up? Is there a thrust bearing to consider or is the motor belt driven to a shaft?

From: mboucher99 <mboucher99@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Sat, November 6, 2010 9:54:38 AM
Subject: [Electric Boats] propeller direction

here's one for you all. i am about to upgrade our 2-blade, 12" dia x 5 (?) pitch prop with a 12 x 13" or 14, as has been recommended by several of you. any other thoughts? the boat is a 27' sloop. the current setup does fine in normal conditions, but is weak in strong currents.

today's question: does it really matter with an electric motor whether i buy a R or L direction prop? forward is currently a left-hand twist, but the setup runs more smoothly and quietly spinning left. can't i simply reverse my switch and have it be a left-hand setup, or are there other considerations - motor - PMAC controller - that i am not considering.

thanks! (again)