ugly but cheap... and it works
09-14-2010, 09:58 PM
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ugly but cheap... and it works
Got the hull at a swap meet for $20, traded a converted 21cc weedeater engine for the 4 stroke (I think it's a 27cc) that I put on it, since the engine had a crankcase it's not the best airplane candidate so I figured this was the best option... the pictures show it before I lowered the engine 1.5", the COG was too high with that large prop and it didn't spin it very fast so I stuck a 15x8 prop on it and it's now getting the rpm it's supposed to turn. I don't know how fast it is but it's good enough for now... have $45 in the radio, $20 in the hull and the rest is pretty much just time...
the pull starter is pretty handy... starts the engine on the first pull almost every time.
09-15-2010, 09:09 AM
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RE: ugly but cheap... and it works
it looks better with the engine lower, and is stronger than it looks for that wimpy little weedie motor, entering the rpm figures in a thrust calculator it's like .6hp and 6 pounds of thrust...
09-15-2010, 11:16 AM
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RE: ugly but cheap... and it works
It's so ugly I threw up a little. LOL Just kidding. I absolutely love the pull start! Very ingenious! I think you've solved an age old problem.
09-15-2010, 10:16 PM
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RE: ugly but cheap... and it works
yeah, the pull start is very handy, I know how hard it is to hand prop a magneto engine and that I would eventually get a prop cage for this thing so it needed an easy to transport starting system, saw someone on youtube years ago that had a much more complex setup that was somewhat similar and simplified it. The guy I got the idea from used a standard starter cone, some dowel running through the middle of the handle and was just too complicated and I don't like spinners so I came up with this idea.
09-16-2010, 01:16 AM
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RE: ugly but cheap... and it works
when the rain stops my pond will have more water, I'll try to get video then. my pond is really small, but enough to run it around a bit 
forgot to share the materials of this thing, it's solid blue foam with plywood skinned sides, bottom and top wrapped with what looks like cotton covered with epoxy... has a fin on the bottom which I'll probably shave off soon...
forgot to share the materials of this thing, it's solid blue foam with plywood skinned sides, bottom and top wrapped with what looks like cotton covered with epoxy... has a fin on the bottom which I'll probably shave off soon...
09-16-2010, 11:02 PM
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RE: ugly but cheap... and it works
finally got some vids of the boat in action:
at the end of the second video you can see it flop... it was fine afterwards, only problem is the top plywood sheet is unglued from the foam again... I'll have to figure out a better solution for that issue... I have some ideas.
this thing doesn't use any fuel... I think I've put about an hour on it and have gone through about a tank...
at the end of the second video you can see it flop... it was fine afterwards, only problem is the top plywood sheet is unglued from the foam again... I'll have to figure out a better solution for that issue... I have some ideas.
this thing doesn't use any fuel... I think I've put about an hour on it and have gone through about a tank...
09-17-2010, 12:14 PM
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RE: ugly but cheap... and it works
Is that full throttle? You seem to be a tad overpropped if it is. Sounds like it's running in the 5000RPM range, you should be up around high 9's. Looks like it handles pretty good though....except for the "incident" at the end. LOL
09-17-2010, 03:08 PM
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RE: ugly but cheap... and it works
it's a 4 stroke so it sounds different, and it's actually spinning at 6400rpm at full throttle which should be about right, I might drop the pitch down a little and try that sometime but it goes pretty well as is. It's not the sturdiest engine, the connecting rod is spot welded steel...
09-26-2010, 01:29 PM
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RE: ugly but cheap... and it works
about the full throttle thing, no, that was about 3/4 which is about what my little tiny pond can handle. And I agree with the engine mount, my steel strap isn't sufficient, it's broken twice now even with heating it to relieve stress...
it flips WAY too much, this time it broke the glue seam on the vertical stab, gorilla glue to the rescue. seriously though, I'm going to lower the engine some more and put a 14" prop on in place of that 15". I'll get some new pics once I lower the engine more. I'm going to have to run some long bolts through the hull, the top plywood plate delaminated from the foam. I'm thinking recessed T nuts on bottom with the rod JB welded in then nuts on top.
would adding some material to the side of the hull that is angled so it can slide easier help? I think it's just catching the back corners and flopping it.
it flips WAY too much, this time it broke the glue seam on the vertical stab, gorilla glue to the rescue
. seriously though, I'm going to lower the engine some more and put a 14" prop on in place of that 15". I'll get some new pics once I lower the engine more. I'm going to have to run some long bolts through the hull, the top plywood plate delaminated from the foam. I'm thinking recessed T nuts on bottom with the rod JB welded in then nuts on top.would adding some material to the side of the hull that is angled so it can slide easier help? I think it's just catching the back corners and flopping it.
10-02-2010, 02:21 AM
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RE: ugly but cheap... and it works
boat is torn apart in several pieces. I trimmed the front of the mount to lower the engine 5/8" for now, might go further... but that's how much room I had between the current prop and hull. the gorilla glue on the rudder is drying, I'll add a couple supports to it so that it doesn't break as easy in further flips.
it'll also get a few other tweaks while it's apart, radio box is getting set into the hull to clear the gas tank, crank vent moved from air filter housing to a pill bottle or something to help keep the water out of the oil... and make a remote oil drain. I don't think I'll change to a 14" prop, it does pretty well with this one, I need to lean it out a bit and it'll pick up a little rpm and hopefully throttle response. It'll also get some fresh paint on the thing so it's not quite so ugly...
anyone have any thought about adding some angled pieces to the side so it'll slide over the water easier instead of catching the corners?
it'll also get a few other tweaks while it's apart, radio box is getting set into the hull to clear the gas tank, crank vent moved from air filter housing to a pill bottle or something to help keep the water out of the oil... and make a remote oil drain. I don't think I'll change to a 14" prop, it does pretty well with this one, I need to lean it out a bit and it'll pick up a little rpm and hopefully throttle response. It'll also get some fresh paint on the thing so it's not quite so ugly...
anyone have any thought about adding some angled pieces to the side so it'll slide over the water easier instead of catching the corners?
10-02-2010, 09:57 AM
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RE: ugly but cheap... and it works
ORIGINAL: rangerfredbob
boat is torn apart in several pieces. I trimmed the front of the mount to lower the engine 5/8'' for now, might go further... but that's how much room I had between the current prop and hull. the gorilla glue on the rudder is drying, I'll add a couple supports to it so that it doesn't break as easy in further flips.
it'll also get a few other tweaks while it's apart, radio box is getting set into the hull to clear the gas tank, crank vent moved from air filter housing to a pill bottle or something to help keep the water out of the oil... and make a remote oil drain. I don't think I'll change to a 14'' prop, it does pretty well with this one, I need to lean it out a bit and it'll pick up a little rpm and hopefully throttle response. It'll also get some fresh paint on the thing so it's not quite so ugly...
anyone have any thought about adding some angled pieces to the side so it'll slide over the water easier instead of catching the corners?
boat is torn apart in several pieces. I trimmed the front of the mount to lower the engine 5/8'' for now, might go further... but that's how much room I had between the current prop and hull. the gorilla glue on the rudder is drying, I'll add a couple supports to it so that it doesn't break as easy in further flips.
it'll also get a few other tweaks while it's apart, radio box is getting set into the hull to clear the gas tank, crank vent moved from air filter housing to a pill bottle or something to help keep the water out of the oil... and make a remote oil drain. I don't think I'll change to a 14'' prop, it does pretty well with this one, I need to lean it out a bit and it'll pick up a little rpm and hopefully throttle response. It'll also get some fresh paint on the thing so it's not quite so ugly...
anyone have any thought about adding some angled pieces to the side so it'll slide over the water easier instead of catching the corners?
http://www.rcuniverse.com/forum/m_10032160/tm.htm
If your boat looks like a river barge, its going to handle like one. A better choice may be to make an entirely new hull and use the right adhesives to hold the skin onto the foam, and also will allow you to build a better engine stand. You could easily make one from thin plywood - 2 layers of 1/4" 5 ply would work plenty fine.
10-02-2010, 11:37 AM
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RE: ugly but cheap... and it works
Thanks,
the problem with mounting this engine, is there isn't really a good way to do it and still get to the dip stick which is why I used the plywood and that strap, which I think I'm going to redo with a different material that's more hearty... I have some 1/8" aluminum sheet, now I just need a blade for my band saw.
I think I'm going to pick up some blue foam to add to the sides of this thing. flat sides are fine for going straight but not for hiarpin turns
the problem with mounting this engine, is there isn't really a good way to do it and still get to the dip stick which is why I used the plywood and that strap, which I think I'm going to redo with a different material that's more hearty... I have some 1/8" aluminum sheet, now I just need a blade for my band saw.
I think I'm going to pick up some blue foam to add to the sides of this thing. flat sides are fine for going straight but not for hiarpin turns
10-02-2010, 04:57 PM
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RE: ugly but cheap... and it works
ORIGINAL: rangerfredbob
Thanks,
the problem with mounting this engine, is there isn't really a good way to do it and still get to the dip stick which is why I used the plywood and that strap, which I think I'm going to redo with a different material that's more hearty... I have some 1/8'' aluminum sheet, now I just need a blade for my band saw.
I think I'm going to pick up some blue foam to add to the sides of this thing. flat sides are fine for going straight but not for hiarpin turns
Thanks,
the problem with mounting this engine, is there isn't really a good way to do it and still get to the dip stick which is why I used the plywood and that strap, which I think I'm going to redo with a different material that's more hearty... I have some 1/8'' aluminum sheet, now I just need a blade for my band saw.
I think I'm going to pick up some blue foam to add to the sides of this thing. flat sides are fine for going straight but not for hiarpin turns
10-02-2010, 09:39 PM
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RE: ugly but cheap... and it works
The way I'm modifying things it'll be easier to lower the engine in the future if needed. The engine runs good with the prop it has if it just didn't flip over I'd be happy and it seems to be more of a hull shape issue than COG at this point, if the sides were angled I think it would skip better. I'm not really rebuilding the engine mount as much as I'm just taking out a couple of the hack things I did last time, making it look cleaner, including paint.
