Electric outboard motor...

[steveo]

So...

I just bought a "dingy" 10 foot inflatable pvc.. made by shark...

it will take a transome motor rated up to 15 hp...

I'm trying to keep this as low budget as possible..

so i'm using a 40lb trolling motor to get me around the water...

but then i thought to myself....

burshless motor conversion.. 100v lipo.. lots of amps...

i have the batteries.. and lots of infinion controllers here..

i just need a good motor to use...

electric brushless motor... and i guess a old gas motor to use the transmission and prop/mounting hardware off of ...

any ideas...

i saw a guy on youtube... with 180hp electric motor on a big boat.. flying close to 55mph...

i wana be at about 10-20kw output minimum..

-steveo

 

[sabongi]

Maybe a AGNI95R directly on the batteries for higher efficiency?

 

[steveo]

i really want to avoid brushed motors if i can..

i don't want to have to setup a reverse contactor if i don't have to...

with brushless.. i could just use 3 speed switch for reverse

 

[Hillhater]

any ideas...

Why dont you read ( and post) in the "Electric Watercraft" section of this forum ?
http://endless-sphere.com/forums/viewforum.php
Its all been done before ,,a few times.

 

[Dauntless]

The forum you selected does not exist.

One possible reason.

Awwwwwm, we'll find it.

http://endless-sphere.com/forums/viewforum.php?f=39

 

[steveo]

i did not realize this section existed..

my mistake.. topic moved

 

[Infinity]

I'm doing the same thing you want to do. Only little bit less powerful. Mine is in the 4hp range. I started of by getting old outboard leg, then buying the electrics for it.

I got ''drowned'' 4hp outboard leg from local auction site for 25€. I used turnigy C8085 style motor. I mounted the motor directly to the mounting plate where the old motor used to be and connected shafts with shaft coupling which I got from ebay. I used two lead 12V batteries in series to power it. On the test drive I found out two things: 1. The speed was enough for me (about twice as fast as I can paddle and lot faster than trolling motors) 2. The motor overheated in seconds, drawing only about 40A at max throttle. Actually there was something wrong with the motor and I send it back to be replaced with C80100 130kv. Now I'm waiting for the replacement... If I get everything done and working properly, then I will create build thread!

My conversion costs about 300€ total (not including batteries)

There ain't so small 10kw+ bldc motor to replace the brushed unit in the trolling-motor. Even if you could fit so powerful motor in there, then it would break it in half. I can recommend you getting (cheap/broken....) real outboard leg about and mounting 10kw+ motor on there.

I can suggest you to use colossus 12 kw motor.
Here: http://endless-sphere.com/forums/viewtopic.php?f=31&t=52083

Or C12090 from here: http://alienpowersystem.com/shop/120mm/12090-outrunner-brushless-motor-130kv-15kw/
Hobbyking has same type of motors.

Anything beyond 4hp gets quickly very costly!!!

 

[steveo]

Please keep me posted

Id love to hear how the new motor turns out for you

Steveo

I'm doing the same thing you want to do. Only little bit less powerful. Mine is in the 4hp range. I started of by getting old outboard leg, then buying the electrics for it.

I got ''drowned'' 4hp outboard leg from local auction site for 25€. I used turnigy C8085 style motor. I mounted the motor directly to the mounting plate where the old motor used to be and connected shafts with shaft coupling which I got from ebay. I used two lead 12V batteries in series to power it. On the test drive I found out two things: 1. The speed was enough for me (about twice as fast as I can paddle and lot faster than trolling motors) 2. The motor overheated in seconds, drawing only about 40A at max throttle. Actually there was something wrong with the motor and I send it back to be replaced with C80100 130kv. Now I'm waiting for the replacement... If I get everything done and working properly, then I will create build thread!

My conversion costs about 300€ total (not including batteries)

There ain't so small 10kw+ bldc motor to replace the brushed unit in the trolling-motor. Even if you could fit so powerful motor in there, then it would break it in half. I can recommend you getting (cheap/broken....) real outboard leg about and mounting 10kw+ motor on there.

I can suggest you to use colossus 12 kw motor.
Here: http://endless-sphere.com/forums/viewtopic.php?f=31&t=52083

Or C12090 from here: http://alienpowersystem.com/shop/120mm/12090-outrunner-brushless-motor-130kv-15kw/
Hobbyking has same type of motors.

Anything beyond 4hp gets quickly very costly!!!

 

[Infinity]

I got my replacement motor (80100 130kv) mounted on my outboard. Nothing gets hot anymore. And my boat is even faster with the new motor.
I forgot my camera at home when I went for fishing and test drive. I hope to get on water next week and get some pictures and video of it

 

[Bazaki]

This 80-100 motor, straigth to where the drive shaft was ? 130kv at 44v ? With a gear ratio at the prop of about 1 : 2,33 ? Do you know the prop pitch ?

I have made several electric outboards but a motor spinning around 6000 rpm is always making noise, I want to build something that is very silent. I´m curious at your results.

Also the original Torqeedo 2.0 and 4.0 make too much noise.

My latest project I will post soon, it is a Hub motor

 

[PracticalProjects]

Sounds like a fun project, I always wished I had something like that when ever i've been in a small boat. Keep us posted how it turns out

 

[Harold in CR]

There actually is no gearing inside a gasoline outboard motor, at least from the 1940's to the 2000's that I am aware of. Worked on/with all sizes and brands, through those years. Forward-reverse has a sliding collar that engages in the lower unit "gearbox" on the splined shaft with either gear to change direction.

What you do, is, change the dia. and pitch, moreso the pitch of the prop blades. The higher number of the pitch, the more "bite" stress on the motor/engine. The lower number on the pitch will give higher RPM's and LESS stress on the motor/engine. Be sure to disengage the water pump, so you don't spray water all over under the hood of the outboard. There is nothing inside the housing that needs cooling using electric motors.

The props have a slip factor because the water is not a solid/static source.

A decent outboard shop "should" have adjustable blade props, so a person can "dial in" their motor to best match the boat. Then, buy the best option prop to match the adjustable one.

Just sayin

 

[Ypedal]

My parents recently moved back to ocean front and are wanting a small boat, i'm really tempted to see if i can do something similar, they are not in any hurry, but when the tide comes in or on windy days, a fair bit of power is needed... i have to ask them what HP outboard the locals use...

 

[Bazaki]

Almost every outboard motor between 4 and 20 hp has a gear reduction of 2.33 : 1 most ICE motors spins about 6000 rpm max which is about 2500 rpm prop speed at WOT.

Higher power outboards have 1.85:1 and F1 boats about 1:1 I believe.

For my projects I use this a lot :
http://continuouswave.com/cgi-bin/propcalc.pl/