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[agemax]

Hi agemax,

Is your boat setup straight out of the box or have you made any modifications?

it is how it was given to me by a friend. it has a 2400mah battery and 480 motors. as far as i know thats the only mods done to it

[Martin (Admin)]

I'm surprised the original radio gear can handle the current! 

[agemax]

I'm surprised the original radio gear can handle the current! 

it seems to run ok, just gets a bit hot 

[agemax]

ok so i have found a 12v pump from a car windscreen washer. made a coil from maleable 4mm copper pipe. the pump runs fine for at least 10 minutes from a 9.6v 700mah battery.
i plan to mount the pump above the original battery with the copper coil around the water pump. then run a pipe from the rear inlet (still need one),wrapped around the battery, the 2 motors the esc then exiting from an outlet on the front of the boat. the 9.6v battery will be mounted in front of the esc which, i gather from other threads will add a bit more weight to the front of the boat and help stability a bit.

[MikeA]

you dont need all that dude crikey, the pump will add weight in an allready slow boat. to cool motors a water scoop is put into the oncoming stream of water, this creates a low but ample pressure to trickle the water around the motor. The reason why it gets hot is because the props are too big. when you oversize props it makes the motors overwork and draw too many amps. this results in the battery and motors overheating. This will eventually be terminal when your motors are burnt out and the esc has melted.

what you need to do is get rid of the mechaninals and electricals entirely and start again with some cheap but affective gear.
You have rc cars right? what have you got??

[Martin (Admin)]

All you need to do is used forced water cooling, no need for a pump.
 You just need a water pick up (usually behind the prop but a bit involved in this case) but yo could extend a 'J'
 shaped copper or brass pipe out through the transom to the back of the propeller... and it doesn't even have to
 be in the water, just a few mm behind the top of the prop will be enough to push through huge amounts of
 cooling for the motor coil etc. Or you can fit a small pipe just in side the transom, sticking trough the hull bottom
 by the siame diameter of the pipe and cut an angle on it 45^o facing forwards.

A bit more here: http://www.modelboatmayhem.co.uk/My_models/03%20laser.htm

[agemax]

i have an original tamiya grasshopper, in the process of being restored,hopped up.
i need to find a source for a water inlet, the only ones i can find on ebay are from hong kong

[MikeA]

on my boats i use a peice of aluminium tube. i drilled a hole in the bottom of the hull then filed the hole into an oval shape, this allowed just the tip of the tube to point forward.

[agemax]

i will try the pick up tube and forced fed water first to see how effective it is, would a hot glue gun be ok to seal the pick up tube or should i use something stronger like araldite?

[MikeA]

hot glue gun works for me  looks like dog poo though

[sumo74]

the screw on props you have are for the stealth boat as above
, not high-wind . the correct props and nuts/drive-dogs can be found on ebay.

[agemax]

the screw on props you have are for the stealth boat as above
, not high-wind . the correct props and nuts/drive-dogs can be found on ebay.

i have the correct props and the dogs are already on the shafts, you cant buy the 3mm l/h thread nuts anywhere. i am in the process of having some made

[Martin (Admin)]

This is what mine looks like....

[agemax]

This is what mine looks like....

thats what mine will look like when i get the nuts made to secure the props

[sumo74]

upgrades done on this one
 2 ch radio
 30amp  speed controller
 rudder
 rudder control rods
 servo
 9.6v battery
 these motors(stealth) don't need cooling as they have fans on shaft at motor.

[Martin (Admin)]

See: http://www.modelboatmayhem.co.uk/forum/index.php?topic=27131.msg324209#msg324209