how to build a rc electric boat from a rc electric car?
Take A cheap rc car take out the circuit board and motors and take a waterbottle and fit it in
sorry , put wrong la the quiestion how to build a rc electic boat using the the green board that still can be use from the die rc car plus the popella with engine from the died aeroplane and helicopter power engine and the big popella of the ufo la !!! sorry !!!!! wrong quiestion!!!
By green board, I assume you mean the printed circuit board(s) that contains the RC transceiver and servo/motor control circuitry... Well, just scavenge the actuators (motors, servos) and control/transceiver board(s), then connect them to the appropriate points on the scavenged RC control circuit... I can't say what any of the specifics are though, since I have no idea what circuits or actuators you're in possession of. Even if I did, I would have to search the mfg info to determine their pinouts and electrical characteristics... If you have a hull and prop assembly, you're already half way there. One thing you can do to reduce your efforts is to make a diagram showing the wiring of the existing toys and label the various connections according to their purposes, so that when you re-incorporate them into the boat you'll know how they were used the first time around. Since you're using components that probably weren't "factory" on the boat, you'll need to make mounting points in the hull of the boat using plastic, wood, glue etc. and provide a place to house the battery(s), as well as balancing the layout so it stays afloat. The last part will be the tricky part, since a boat needs to be balanced carefully to avoid capsizing do bad component placement. Even once you've found the optimal arrangement, you will probably need to add a bit of ballast to various locations in the hull to fine tune the float.
Well, you're still going to need a hull. After that, my next question would be whether the board can supply enough power to run the airplane/helicopter engine. I'm guessing probably not, so you might want to use a separate power circuit and a relay, unless you want to have speed control (I would). Then, of course, you'll want to be able to steer. I assume your car has a steering linkage that can be used to move a rudder without too much trouble. The other challenging bit will be to run the driveshaft through the hull and into the water without leakage. That will require some kind of sealed bearing. Have you considered just making a swamp boat?