Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[reaperspear]

Hi, I am new to model boat building and have built a 33 inch pt109. On the second sail it went well and strait up onto the plane, the wires to the motor got hot and shorted and that finished the esc. I have upgraded the wires and have ordered a water cooled esc as it had got hot as well. My question is where in the hull should I put the inlet and outlet so that the water will circulate.

[AlanP]

The water pickup usually goes at the stern, the cooling water should goe through the ESC first and then the motor and the outlet on the side of the hull.
Is it a brushed or brushless motor?

Alan

[Mad_Mike]

Hi, I am new to model boat building and have built a 33 inch pt109. On the second sail it went well and strait up onto the plane, the wires to the motor got hot and shorted and that finished the esc. I have upgraded the wires and have ordered a water cooled esc as it had got hot as well. My question is where in the hull should I put the inlet and outlet so that the water will circulate.

Ive just recently built a semi scale pt 109 from here:

http://www.building-model-boats.com/model-boat-plans-store.html

did you work from these plans or others and can we see some pics of your boat?

[dodgy geezer]

Hi, I am new to model boat building and have built a 33 inch pt109. On the second sail it went well and strait up onto the plane, the wires to the motor got hot and shorted and that finished the esc. I have upgraded the wires and have ordered a water cooled esc as it had got hot as well. My question is where in the hull should I put the inlet and outlet so that the water will circulate.

You can buy different sized ESCs (measured in Amps) for different sized motors and battery setups. Can you tell us what your motor, ESC and battery are? This will help us work out if you are using too small an ESC for that setup. If you are, cooling it may still not save it...

Propeller size is also important - too big a propeller will put a large load on the motor and increase the current drawn through the ESC. A few pictures will help us see if everything looks right...

[reaperspear]

Ive just recently built a semi scale pt 109 from here:

http://www.building-model-boats.com/model-boat-plans-store.html

did you work from these plans or others and can we see some pics of your boat?

[malcolmfrary]

That 4 bladed prop should do a good job of overloading the motor, causing excess current and overheating.  Good for use on a tug, with the right motor, less so for a performance boat. 
What type of motor is fitted, what type of ESC did you burn out?

[Mad_Mike]

When i built this boat i used a standard 540 motor throught a 4mm propshaft, I spin this propeller on 8.4v

http://www.hobbyking.com/hobbyking/store/__7358__Turnigy_4mm_AquaProp_31x22x14mm_.html

cooling is still required.

[dodgy geezer]

Here is a typical water pickup for a boat like yours. Hydroplanes typically have surface-mounted pickups on the hull to cut down drag, or pickups taking spray from the propeller, but non-racing boats usually have a scoop like this....