power system for self designed boat??

[yorbenator]

hey guys,
i'm building a self designed boat and am looking for power system i clould drop in it, i want it to be quite fast...i was thinking somewhere along the lines of of a spd 400 motor

but because i'm on a bit of a budget i was wondering what would be a good powerplant??

the boat has a length of roughly 10.5 inch and is 5 inch wide, it is a very shallow design, it should have about o.5 to 0.8 inch of the hull in the water while not moving.

thanks in advance for your help...

[Doraemon]

hey guys,
i'm building a self designed boat and am looking for power system i clould drop in it, i want it to be quite fast...i was thinking somewhere along the lines of of a spd 400 motor

but because i'm on a bit of a budget i was wondering what would be a good powerplant??

the boat has a length of roughly 10.5 inch and is 5 inch wide, it is a very shallow design, it should have about o.5 to 0.8 inch of the hull in the water while not moving.

thanks in advance for your help...

You can go to the Traxxas parts section at Rotor for a Stinger motor!! Can't remember the exact price but think its less then $20. But judging from the size of your boat, even a standard 380 motor should do the trick - these should be around $10. With a hull of only 10.5 inches long, the challenge is cramming the motor, speed control, batteries and (micro?) RC system into the tight space and still achieve an ideal weight balance - otherwise, your boat won't get on plane. Perhaps you can post some pictures of your hull and ask Stuka for his expert opinion...

Also, what kind of drive system do you intend to use? A submerged prop or a surface drive?

[Richard]

i think a 540 motor will do the trick.. Powerful enuff...

[PCC]

errr... 10inches. Mine is 15inches and recommends a 400 motor. I think a 540 is risky. Everything needs to be sized to the 540 drain and with the batts/elects/motor weight - may sink the boat.

[Richard]

that depends.. If i am not wrong, stuka did his tug boat ard 30 cm and used a permax 600!! its works too!!.. must really look at his hull design...if its a deep vee, i dun advise 540.

[yorbenator]

hi guys,
i was thinking about a surface drive...the hull is only about 1.3 inches deep ( i think ) but prety wide, i don't think that a 540 would fit though...i don't have any pics of the hull, but i will post some screen shots of my simple cad drawing when i figure out how...

[Richard]

1.3 inches deep?? thats very shallow loh... I advise you go the website of the 400 motor and get the weight(use a alternate weight like a stone for testing) and put in all your electronics on the boat for a weight test in water and see whether it exceed your water line.

This is the most cost effective way to see if its too heavy for your hull.

Good Luck!!

[yorbenator]

as promised, heres the CAD drawing

[yorbenator]

ok, i'll try that tommorow

[stuka]

i think the buoyancy will be overcome by the weight of regular gears and electronics. You really need to go micro for this one.

[Richard]

you can find the info at http://www.multiplex-rc.de/

Permax 400/7.2V motor #332546

PERMAX 400 7.2 V # 33 2546 For longer flight times when used with a 7-8 cell flight pack and 6 x 3” propeller.Specification:
Dimensions: 27.5 Ø x 40.5 mm
Weight: 73 g
No-load speed: 17,400 rpm
No-load current drain: 0.7 A
Maximum current: 8 A
Current drain at max. efficiency: 3.5 A
Shaft Ø: 2.3 mm
Direction of rotation, “+” to red: right
Typical operating voltage: 5 - 8 V
Max. temperature: 80º C

[yorbenator]

ok guys just did a quick test; loaded her up with a bunch of heavy things until she was about to take on water...
and weiged them and came up with 382 grams...(not alot i think )so prob have to start hinking about something a bit smaller then 400

[PCC]

gulp.... now I am worried. I am fixing my 400 sized boat of 14inches and its already like more than 500gms and has less buoyancy than your hull. Hope mine doesn't sink. Time to buy smaller servos, receiver, packs - everything!!! Your weight of the hull is now my target

[yorbenator]

... I am fixing my 400 sized boat of 14inches and its already like more than 500gms and has less buoyancy than your hull...

what do you mean?

[Mad Armour]

gulp.... now I am worried. I am fixing my 400 sized boat of 14inches and its already like more than 500gms and has less buoyancy than your hull. Hope mine doesn't sink. Time to buy smaller servos, receiver, packs - everything!!! Your weight of the hull is now my target

Time to go for brushless power! Hahahahaha.....