Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Any Other Builds => Topic started by: portside II on January 24, 2009, 11:10:30 pm
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After seing a pop bottle recovery boat and a yacht on here some time ago and thought could i build one .
So into the workshop and came up with this ,
(http://i168.photobucket.com/albums/u176/darran77/P1010192.jpg)
(http://i168.photobucket.com/albums/u176/darran77/P1010199a.jpg)
basicly its 4 75cl water bottles , a direct drive motor/shaft,brass kort prop(what i had to hand at the time) , battery and radio gear mounted on an alloy board with alloy struts ,well it looked ok on the bench but on the water it sank , so a bit of ballast (styrene foam) and it was ok .Yes it moved under its own power like a submarine , all it wanted to do was either dive or make froth.
So back in the workshop i swapped the 4 small bottles with 3 big ones and ended up with this,
(http://i168.photobucket.com/albums/u176/darran77/P1010258.jpg)
basicly the same set up but a smaller battery and a longer shaft and 2 blade 65mm plastic prop, it went ok , as well as 3 pop bottles can go .
But i still aint happy so the next thing is to get 2 2ltr pop bottles cut and join them together on length and fit the radio motor etc in that with a keel and see what happens .
Still waiting for the tablets to take effect ,
daz
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Ha ha. i didn't look properly at the first picture and thought it was 4 x 2ltr pop bottles and a washing machine motor. :embarrassed:
On the subject of ballasting, you could try puttin some water (will slosh about) or sand in the rear bottles. This may stop the nose from diving.
I think the biggest problem may be weight so far above the waterline.
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Portside,
Keep taking the tablets. Next you need to build a rescue boat for the sunken rescue boat!! %% %%
Only joking.....
Barry
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The heir to the de Rothschild banking dynasty is building a far more ambitious pop bottle boat to sail the trash area of the Pacific where all the oceans waste ends up. Do a Google search for Plastiki One report says he looks like Lord ! {:-{
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Ha i will be waiting for his phone call , can i copywrite my designs this chap sounds as if he is a sandwich short of a picnic .
Tiger i tried the water balasting method with mk2 ,only in the rear bottles to give a little lift forwatds , but she still dives in reverse.
That one has gone to the recyling center in the landfill sky , so when i get the new bottles mk3 will be started.
watch this space.
daz
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It looks to me as if the nose down attitude results from what appears to be the steep incline of the prop shaft. A great deal of power is apparently being absorbed trying to push the rear up out of the water.
Easy to test for: does she float reasonably level when static and then immediately nose dive when power is applied?
Roger in France.
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Kort nozzle drive perhaps.
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thats the one with the plastic screw prop on , you have to remember there was a 12v battery weighing it all down.
daz
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The 12v battery may have been part of the problem. All that weight so far above the waterline acting like a giant upside down pendulum, and the prop giving it a push/swing, so to speak.
Thinking out of the box for a moment.
Maybe if the battery were smaller, and the boat was longer.
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Yes that would be better , less weight and longer length . thats why i am thinking of a torpedo shaped hull and racing pack to power the motor , will probably last longer than the SLA and give more speed , still no idea on design.
daz
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Some crazy thoughts for getting the c of g down.
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thats a god idea there , and it may develop into a prototype , i was thinking more in the lines of using two bottles end to end with some ballast and stabelizing fins .
daz
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Rather than stabiliser fins, you could use a drop keel. And this would creat its own problems.
I still think a Cat is the best way forward, because of the tendancy to roll. Especially if the cofg of above the waterline.
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Another thought.
Double up what you suggest, strap them together and either have differential steering or shared ESC and shared rudder servo.
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Ooh :o thats a thought , now all i need is time and some space in the workshop .
daz
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I shall have to have a go at one of these.
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Oh no :o , this is how the springers started :embarrassed: O0 .
daz
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Hmmmmmmmm...this thread and the sketches have got me thinking, which is never good.
Please keep the ideas coming.
One question that comes to mind: what adhesive works with plastic bottles and, say, sytrene?
Cheers,
Capt. Spaulding
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tie wrap's :}
not sure , more than likely standard styrene glue will have to do the blob test .
daz
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Tie wraps are a very good idea. They are used by the folks who make ROVs, I believe.
Any place for PVC pipe in this brain-storming process? It's strong, inexpensive, easy to work with, comes in various diameters, can easily be made water-tight, and has pre-made fittings and angles.
Cheers,
Capt. Spaulding
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Hmmmmmmmm...this thread and the sketches have got me thinking, which is never good.
Please keep the ideas coming.
One question that comes to mind: what adhesive works with plastic bottles and, say, sytrene?
Cheers,
Capt. Spaulding
Use a glue gun!
These bottles look like good submarine building material.....