T-Pain Is On A Boat: Re: [electricboats] Quest for 2X Hull Speed

Ryan,
Nice cooling system. Do you monitor the current or wattage? If not, there are shunt displays on Amazon for $20 that really help to understand the performance. It would be helpful to know that in relation to the amount of heat you are generating. I did finally find one of the Amazon vendors posted the datasheet. It looks like that motor is about 80% efficient within the designed operating range, so combined with the current/wattage above that would give some indication of the heat generated. Also, I think you can reverse two of your motor leads to reverse the direction of the motor. Nice find on the Piranha propellers, thanks.
Keith

On Tue, Oct 27, 2020 at 08:34 AM, Ryan G wrote:

here are some pics of my retrofit:

I really wanted a water-cooled motor, so I wound 3/8 aluminum tube, also from amazon, around the controller and motor body, as both got hot enough to fry eggs. Remember, for every 20 degrees F over 180, service life of metal on metal parts is reduced by a factor of around 50%!!!

I used 3/16" plate aluminum, some angle, and 1/8" blind rivets to fab the adapter bracket.

Also visible in photos is a 48v to 12v step down converter (another amazon find at $15), to power the small daphrgm pump to provide cooling. My original plan had been to use the impeller still located in the foot of the old 9.9, however, and much to my chagrin,

The motor kit I bought in "forward" operation mode (sold as an e-bike mid-drive retro), counter rotates the original 2 stroke powerhead, and "reverse" is limited to like 20% of forward. so that means that the f/w selector lever is actually reversed now with the electric motor. That also means that the offset on the impeller housing is backwards, so the electric pump was the simplest solution.

Also note worthy- the thrust bushings still function as intended, but being that the gears are now counter rotating their original config, I thought it would be wise to drain the gear oil and refill it with zddp additive, undiluted, for a period before replacing it with my standard Lucas gear oil; to help to reduce any potential galling and re-burnish the gears in their new rotation direction.

The most challenging aspect of this re-fit was developing a power coupling to go from the 11-tooth sprocket meant for bicycle chain and getting it to mesh acceptably to the 4-square cut-tooth spline of the lower on the Johnson. After wrecking the shaft on one motor (cut to d-shaft that subsequently snapped off), I ended up chopping the ass end off of the crank from the original locked up powerhead. I then traced the 11-tooth sprocket onto the cylinder that was left on top of the original factory female spline, and carved out a relief to accommodate the sprocket with a dremmel and cutoff wheel. This ended up being ideal because it allows a small amount of radial, axial, and orbital play, and thus greatly reduced vibrations that were beating everything up with my previous coupling attempts. One good hunk of red and tacky #2 grease in the relief also prevents corrosion and helps the parts to polish themselves to their own broken-in happy place.

I mounted the hall effect throttle where the original twist grip had been for testing, but I have another set of throttle controls forward now. To avoid running another cable in the gunell, I used 3/8 stainless rod to make a linkage, and simply slaved it to the primary motor, an evinrude 140. The foot of the big motor does make some drag, but the my aluminum cabin cruiser can still maintain 4-5 mph with moderate wind and current.

Oh, and the prop! Many moons ago, when this outboard was still 2 stroke, I was delighted to find that the old omc 9.9/15s were the smallest available pirhana propellers... they are a boon for expirimenters and tinkerers like us. They make a hub with 3 dovetails for this model, that allow the exchange of individual veins of the prop. They also offer the veins in a variety of pitches, so I took the 15" pitch veins out and swapped them for 5" veins (in its previous life the motor had pushed a Lowe 1256 v-hull at a fast clip, vastly different than moving at near hull speed with a 25 footer)

On Mon, Oct 26, 2020 at 5:53 PM, Colin Davis

<colin.a.davis@gmail.com> wrote:

Ditto on retrofitting an old Johnson with a BLDC...! Details here:

https://ensign748.weebly.com/

Ryan is right - it's not a simple retrofit. And the propeller is all wrong for an electric motor. But I wasn't going for fast, just quiet.

On Mon, Oct 26, 2020 at 4:28 PM Ryan G via groups.io <ryanwestbrookcary1=yahoo.com@groups.io> wrote:

I retrofitted an old Johnson 9.9hp with one of these:

Motor eléctrico sin escobillas DC Kit completo de 48 V 2000 W 4300 RPM motor de alta velocidad, con controlador de 33 A 15 Mosfet, pantalla de batería LCD de acelerador, scooters eléctricos, moto, motor de transmisión media, pieza de bricolaje

Motor eléctrico sin escobillas DC Kit completo de 48 V 2000 W 4300 RPM motor de alta velocidad, con controlador de 33 A 15 Mosfet, pantalla de batería LCD de acelerador, scooters eléctricos, moto, motor de transmisión media, pieza de bricolaje

Motor eléctrico sin escobillas DC Kit completo de 48 V 2000 W 4300 RPM motor de alta velocidad, con controlador de 33 A 15 Mosfet, pantalla de batería LCD de acelerador, scooters eléctricos, moto, motor de transmisión media, pieza de bricolaje

Far less expensive than any of golden motor's offerings, although it did require some thought and skill to marry the two into a workable platform.

On Mon, Oct 26, 2020 at 10:30 AM, cpcanoesailor via groups.io

<cpcanoesailor=yahoo.ca@groups.io> wrote:

Interesting project. Thanks for sharing.

I use a Haswing Protruar 1.0 motor with an APC 11x6 tractor prop. I figured out that I could mount the control head backwards, so the prop is facing forwards. I added a spinner in front of the prop to minimize drag. The only noticeable drag now is from the vertical shaft. I typically run the motor at about 50% power, about 300W, giving 3-4 knots boat speed (multihull, some drag). I only notice cavitation if the water gets quite choppy.