Tiny Speedboat Build

Boats up to 15' for oars, power or sail. Please include the boat type in your question.
Jetdriver69
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Tiny Speedboat Build

Post by Jetdriver69 »

Hey all, new to the forum and to boat building. I just finished modifying to a great extent a PowerWheels Dodge Viper for my small grandson and was looking for a new project.

I saw youtube videos of a father in Australia who designed a very small, weedeater motor powered speedboat for his 4 year old grandson and thought what the heck, that would work.
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So as I was sitting in a hotel room on the beach in Santa Monica last November, I designed a 6.5 ft foam, wood and fiberglass mini cigarette boat powered by a Zenoah 320 4.5 hp RC boat motor coupled to a 3D printed 70mm jet drive.

The first picture is the pile of foam and wood I started with.
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These next two photos are after cutting the sections of foam out with a hot wire and glueing them together.
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Yes I know using this type of foam isnt the best for structural integrity and in hindsight, should have made the boat out of wood entirely. But after 3 layers of epoxy and fiberglass boat cloth and a whole bunch of epoxy thickened fillets in the joints, the boats looks pretty rigid for its use in a very calm pond or lake setting. Besides the kid is only so small for so long.

I'm just about done with the boat so I can post a few pictures a day until I catch up with the actual progress.



Fuzz
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Re: Tiny Speedboat Build

Post by Fuzz »

That is a great project! Grand dad..............lean, mean, spoiling machine :D That is the best thing about grand kids, at least that is what I am told. Please post as you can and show the process to us.

Jetdriver69
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Re: Tiny Speedboat Build

Post by Jetdriver69 »

In order to move the CG a little toward center in the boat, I wanted to move the engine and jet drive a bit forward.
So I made a spacer for the water outlet out of pine which will be fully encapsulated with epoxy resin.
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Attaching outside battens to the boat
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Fuzz
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Re: Tiny Speedboat Build

Post by Fuzz »

Enjoying seeing this :wink:

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cape man
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Re: Tiny Speedboat Build

Post by cape man »

Too cool!!
The world always seems brighter when you've just made something that wasn't there before - Neil Gaiman

jbo_c
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Re: Tiny Speedboat Build

Post by jbo_c »

I think these are great and look like fun. Most of the ones I’ve seen seem to be a tighter fit than I’d be comfortable with from a safety standpoint. Make sure you leave plenty of unobstructed space to slide out in the event of capsize.

Jbo

Jetdriver69
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Re: Tiny Speedboat Build

Post by Jetdriver69 »

Thanks for the comments. Yes leaving plenty of space to get out but the boat is pretty wide compared to the length so it should be fairly stable

I skinned the hull with foam sheets using clamps, screw blocks and marine adhesive.
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Filled in the keel voids with expanding foam
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Used epoxy body filler to fill in the seams and filled the bow section with contoured pieces of the foam
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Jetdriver69
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Re: Tiny Speedboat Build

Post by Jetdriver69 »

To get the proper shape of the bow, I used thinner strips of foam glued vertically.
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In places I couldn't clamp or use screw blocks, I used sharpened wooden sticks to keep the foam in place while the glue dried.
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After all was dried, I used a knife to trim away the excess.
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Jetdriver69
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Re: Tiny Speedboat Build

Post by Jetdriver69 »

I glued thin plywood to the foam battens for a bit more protection
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I made a trailer out of PVC pipe and wheels from Harbor Freight
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Dry fitting the decking before cutting out the engine and cockpoit openings
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narfi
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Re: Tiny Speedboat Build

Post by narfi »

Very nice!
You sure grandpa or dad aren't going to feel they need to try it first and swamp it before the little guy gets a chance in it?........
Can't wait to watch the rest of your progress!!!

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