Opinion/Idea Request (Convert string trimmer into trolling motor)


Old 08-02-06, 12:33 PM
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Opinion/Idea Request (Convert string trimmer into trolling motor)

I am thinking of converting a curved shaft string trimmer into a boat motor/trolling motor and would like some ideas and opinions before I destroy a working weedeater. I realize they have very little torque but a lot or rpm's. It just seems to me that it should be workable. A small boat motor 1-2 hp is several hundred $$$, but you can buy a weedeater at Wal-mart for about $65.00.
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Old 08-02-06, 12:36 PM
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Interesting idea. Be a noisy bugger, tho; scare away all the fish.
Old 08-02-06, 05:09 PM
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I think you'd need to gear it down...water isn't a "high-RPMs" environment. You need torque to push a blade through it, and if you had torque and RPMs...you'd run the risk of cavitation, losing efficiency and possibly damaging the prop.
Old 08-03-06, 10:51 PM
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We've toyed with that idea here at my shop a time or two but never tried it. I would think you'd want to seal the cable end against water. Prop size and pitch would be a big issue. Who knows what would be the right size and pitch without experimentation. Let us know if you try it and how it does.
Old 08-03-06, 11:48 PM
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I'd try it with a refurb (since they are alot cheaper) or a good used one before I bought a new one and never got it to work... sounds like it migh though.
Old 08-04-06, 04:39 AM
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there was a guy selling plans to do it on ebay last year , I bookmarked his auctions and was thinking about it .

I looked breifly over there and didnt see them but you might want to spend some time searching there and on the net .
Old 08-04-06, 05:16 AM
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I'm with Tow Guy, be noisy, which is the opposite of what you want for a trolling motor. I sure wouldn't want to be trying to fish the same lake as you.

Along with what has already been said, you need torque, not RPM. Most boat motors max out at around 2200-2500 RPM, so do most piston aircraft engines and large truck/equipment diesels, but they have loads of torque.

The speed you get out of the motor is adjusted with prop pitch.

On the other hand, I think a PAIR of large trolling motors would make a right fine small lake/pond boat.

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