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Permalink Reply by Tom Hruby on May 19, 2012 at 2:36am

Hi Donnie,

I will begin by saying that I have not yet done such a conversion, but if you are handy with tools it should not be any different than  connecting an electric motor to an existing prop and shaft.  Electric motors can be attached either vertically or horizontally so in your case what you could attach the motor directly to the top of the vertical shaft coming out of the saildrive (if the motor is properly supported).  The easier option would be to put pulleys on the vertical shaft and then position the motor next to it with V-belt pulleys or a chain drive (like they use in go-carts) on the motor shaft.  Depending on the amount of power you need you will have to use two or three belts to transfer the power to the shaft.  Using pulleys and V-belts will also let you better match the rpms of the motor to the rpms of the existing propeller. 

If you want to keep your transmission (rather than controlling reverse through a change in the motor polarity) you would have to atttach the electric motor where the existing motor attaches, in front of the transmission.

There have been a number of discussion on rpms and connecting electric motors to existing shafts in this discussion group.   You  may want the check them out.

Hope this helps,

Tom

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Permalink Reply by Geo on May 19, 2012 at 4:24am

Hi Donnie ! 

Did you find a boat with a sail drive ??? YES ! look on this site under "The ELECTRIC FLEET" go to "COINCEDENCE"

THIS is Eric Harm's EY installation with a saildrive. There are great pics here. 

Best Regards

George

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Permalink Reply by Donnie Harris on May 23, 2012 at 10:02pm

Thanks, I had missed that.  I thought I might have found one, but apparently people don't really respond to their listings on the internet.  Grrr.

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Permalink Reply by Bill Tomlinson on May 24, 2012 at 5:50am

Good question Donnie, as there are a lot of older saildrive/diesels out there.

The quick answer for Electric Yacht is-- Yes.  However there may be a few details that you will want to address specifically before plunging ahead.

We have completed installations mating up with Sillette-Sonic, Volvo and OMC saildrives.  No Yanmar installations yet, but that is just a matter of time. You can mate-up the appropriately sized EY System with the drive shaft on the saildrive, much as you would align it to a straight-drive shaft. Note that the Sillette saildrive is itself anchored to the hull, not the engine as in the case with Volvo and Yanmar. Either system works with our universal mounting system.

The next thing you need to know is the speed reduction built into your saildrive gear case. I think most are around 2:1 to 2.5:1. This generally works acceptably as a reduction, as our systems will have cogged pulleys in an adjustable arrangement whereby we can optimize your existing prop.

With an EY System, the single lever throttle control reverses the rotation of everything from the motor to the prop.  You simply leave the manual shift-rod in forward forever, so that all forward and reverse thrust is current controlled.  Getting rid of the transmission is just a good way to jettison more weight and power waste.

The last thing you will want to check is the condition of the saildrive. While it no longer needs a functioning dog-clutch, it does need to spin.  Last I checked, the cost of a replacement is over $3K, and having a yard drop a shaft-log, shaft and prop into your boat should be far cheaper.  Chances are good that you can find used parts for most of what you will need.

Good luck with it, Donnie.  You can reach our Chief Engineer, Scott McMillan at 763-370-2610 if you want more details on your specific application.

Bill Tomlinson
Director of Marketing
Electric Yacht
Golden Valley MN
612-619-0890

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