Electric Outboard Design

[LSU SolarSplash]

So I am working on a solar powered boat. I am trying to design the drivetrain right now. Unfortunately, I do not have a lower unit at the time. Do you guys have any suggestions of how I could find dimensioned drawings for different motors?

[Thin water]

Don't try and re-invent the wheel. You can use a stock outboard lower unit, available for little cost if they have a blown powerhead, and mount the electric motor in place of the powerhead. I saw a Brigs E Tec mounted in this way. It really moved out. I have a couple of 2 hp 90 Volt DC motors I considered doing this with but they are to weak to be of much value.

Most boat inboard engines are based on some type of car engine. You may have better luck looking for as a car engine if you know what lower you may end up with.

Good luck, cool project

JIM

[LSU SolarSplash]

Yeah, we've actually speced out our motors, I have the "powerhead" designed, but I'm trying to work on the interface between it and the lower unit. I'm just having issues finding dimensions for lower units in order to pick one out and finish up my CAD drawings.

We went with similar motors to the Etek, but found a german one that had better performance characteristics for what we're looking for. For our sprint race, it will actually have 3 Perm Motor PMG-132 motors. I hope to get some video of the boat when we get to our testing phase. I'm sure I will and I'll post them on here for everyone to marvel at. I do know one thing, it will be the fastest any boat has ever moved in the lake in which we will be doing the testing (there's an electric only motor restriction).

[Thin water]

It would be a lot easier if you had the lower you wanted to use. You could write the company that makes it and probably get specs and if not you could break out an old fashioned set of calipers and measure it. From your measurements it would be easy enough to make up a wooden motor mount/template to verify it will fit before making the final version. Are you going to run all three motors into one lower? I have seen this done with electric car conversions and it worked out well. They ran a set of belts around a pully on each motor. The motors were mounted in an assembly shaped like a diamond when viewed from he rear. The gearbox was the lower point of the diamond.

[LSU SolarSplash]

Originally Posted by Thin water

It would be a lot easier if you had the lower you wanted to use. You could write the company that makes it and probably get specs and if not you could break out an old fashioned set of calipers and measure it. From your measurements it would be easy enough to make up a wooden motor mount/template to verify it will fit before making the final version. Are you going to run all three motors into one lower? I have seen this done with electric car conversions and it worked out well. They ran a set of belts around a pully on each motor. The motors were mounted in an assembly shaped like a diamond when viewed from he rear. The gearbox was the lower point of the diamond.

Yeah, that's the plan. They'll be connected by chain and sprocket, with the front motor's shaft connecting down to the lower unit. I've got the mounting plate drawn in AutoCAD, but I just need to spec out a lower unit.