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Simple hull!

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boat gas plans
26K views 55 replies 12 participants last post by  Aero165 
#1 · (Edited)
Been playing on cad. to come up with a very simple plan for a gas rc boat hull for people new to the hobbie or just a knock around hull for the kids.:thumb:
This one will fit most weedie engines straight in so it suits homebuilders like me.
Built from the bottom up as a simple flatbottom but having 1 1/2" runners laminated underneath once built for a slight tunnel effect when at speed.
The one I will be building will have the rear modified to slope down from the back of the engine to the transom to get rid of the boxy rear end! I can post the DXF file if anybody is interested.

V1-Punt Runner.


test fitting the main framing!


 
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#40 ·
turned out fantastic mate. look forward to seeing a vid.

what sort of speeds ya think the hull would be stable for?
 
#42 ·
was the design similar to your drag hull. what sort of speeds have you had that too.

Just curious thats all.

Might have to build something myself one day and slap a RCMK motor in it see how it goes lol
 
#43 ·
My drag hull is actually slightly rounded on the bottom so this one will run very different.
Not sure on the top speed as I dont own a GPS, but it was quite fast for a homebuilt.
I robbed the radio gear/carby for another project not long after I finished building it.
 
#47 ·
looks good mate.

But I think you should invest in a RCMK motor or even a stock PUM260. They rev A HELL of a lot more than that.

In the video it sounds like my RCMK did when I was running it in. And well it still had like another 8000 - 10000rpm once it was tuned.
 
#48 ·
I think you miss the point, what he is doing is boating on the cheep, by building himself and using old wipper snipper engines he can have some uber gear at a fraction of the cost. After seeing these boats and the gear that went into them, i kind of regret throwing out a 12 month old wipper snipper engine just because i managed to break the line spool. I could have used it in a boat or some other creation, a new tuned pipe would have cost me the price of the sheet metal as my brother makes race pipes for 2strokes in his spare time and has about 10K's worth of software for designing them as well as port mapping and other assorted creations.

Going to the tip later, if i can find a working wipper snipper in the junk shop im buying it and building a boat. I have the carpentry skills and tools and the rest of the materials are pretty cheep. Don't know what the wife will think if i start building a boat, still have not finnished the scale chassis i was working on.
 
#49 ·
I dont miss the point because the rcmk motors are cheap as chips for what they are and trust me when I say it will be 500 times more fun.


I have 3 large boats here. 1 with a rcmk pushing 90kmhs, another with a stick 260pum and clutch for just fun and another cheapo with a whipper snipper motor for mucking around also.

Oh and another electric boat that should crack that magic 100kmh mark but yet to get it wet just waiting on some bits.

Its great to see the home built hull and I think he has done FANTASTIC but I would like to see how it handles a motor that will rev.
 
#50 ·
Hey love the final result looks sweet. Have built a few smaller scale electric boats, but without any research, just an idea in my head. Can you explain what the function of the runners are? I Have a design that i am working on at the moment and am wondering if it is something that i should incorperate into my design?
 
#51 ·
Thanks for the replies guys!
I would love to run a proper marine engine but unless one magically appears for my B'day next month my disability pension just wont allow it, once rent is paid Im lucky if I can cover my other bills!
The vids were with the stock muffler that came with the 40cc motor and a prather 270, I will try my Octura X482 next time and throw my tach on it. For a $5 motor Im pretty happy with it at the at the moment, I think the coil may be limiting the rpm aswell.
The COG is also too far foreward, my fault building from scrap offcuts and using 9mm ply for the frames it just made the front too heavy.

'Pro.28Avenger' The runners are there to help straight line stability and help the flat bottom break loose a bit quicker, some full scale flat bottom drag boats use a similar idea.
 
#53 · (Edited)
Love your work and the happy voices during the video.

I found this while surfing (http://www.marinespecialties-rc.com/mc25.htm) any good for your needs?

It's amazing what can be achieved with a little hard work mate. Pensioners United! Show em how to do it on a tight budjet.
 
#54 ·
Thanks mate!
I have a couple of those(your link) weedies in the shed, Fairly heavy casings etc. for thier output.
Look for the newer Talon snippers at the recycling centres/dump if your after a weedy style engine for a home build, they have 2 bolt full crank clone engines in them (25cc).
Flywheel and pullstart are opposite the output (unlike the RTR boats)so they sit nice and low, my Zenoah pullstart bolted straight up to replace the heavier 'Easy Start' assy.
Im sure mounts could be bought to fit them aswell.
 
#56 ·
Hi guys! I plan on using this design to build my first boat using a Husqvarna 28cc whipper sniper I found on the side of the road. I have a few questions

1: What size servos would be recommended for the throttle and rudder?

2: Roughly where should the engine be placed? I plan on building it at 1.1m long

3:Will the spark plug interfere with my radio gear? I've never used a petrol engine before.

Thanks!
 
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