Wall Mart boats, converted to RACERS for CHEAP

[Gonflyin01]

I have a modofied "sun runner" It is a cheap wall mart boat. 16 inches long, crappy radio. And little motors with 1 bladed props.

BUT!!! I couldnt resist. I am an airplane guy so I have all the stuff. I put a DD speed 400 Race motor in it, 20 amp ESC 4 channel RX and an 8 cell 1650 NiMH pack in it. This thing goes about 15 mph (Not to bad I'd say for 30 dollars!) BUT, the motor gets so hot that t melts the hot glue that i glued it down with. i dont want to gear it, but Is there a simple cooling system that i can make for it?

At the cost of 3 stiches (knife slipped, OUCH!!) i cut a cooling duct im the front 1.5" wide, and about 3.5 long but i dont think this will be enough. Is there an Extra cheap and simple way of cooling that motor? I may have to buy a heat sink also..

Has anyone else converted theese cheap boats from wallmart into fun boats?
In the Foamie forum for planes I know we are all making the foam gliders into RC planes...SO WHY NOT BOATS NOW??????

[George Pfeifer]

Solder short pieces of brass tube to the motor terminals and hook up fuel tubing to a water pickup and exit. that should help keep the brushes cool. You can also wrap an aluminum tube around the motor and run water thru that if you have room.
Put large diameter Weed Wacker string inside the tube before you wrap it around the motor, then just pull the string out and you have a nice coil without crimping the tubing.

Then you might want to seal up that vent that you created, cuz any water on the electronics will probaly kill them. With water cooling you shouldn't need any air cooling, and it's not worth the risk to have holes in your boat.

Might want to check you local hobby shop for some better plastic props that would fit also. Kyosho, Traxxis, etc have replacement props for some of their stuff. Try the Octura 431 plastic prop, but check for excessive heat frequently. Boats draw horrific AMPs, and you can fry an ESC quickly.

Good Luck;
George

[Gonflyin01]

I have a new prop on it... it is a great planes somthin.. for boats not planes.. I will try the water cooling...Just need some brass tubes. Is my 20 amp ESC to small???

[George Pfeifer]

Take a look at www.microhydros.com they do a lot with the 400 motors and it will give you some info.

George

[Gonflyin01]

I already built that little green hydro...LOL! seriously took about 6 hours. Just tryed it in my bath tub, my esc is not working right, I will switch it later.

My hydro is all black, with red tips faded into the black on the out riggers. And hes HITEC RACING decals on it. 15 oz sound about right?The back sits about 1/4 inch fro mthe watter not running, Will I get a hull full of water????
Thank you also for your concern

[Gonflyin01]

Should there ba a CG for my Hydro? the prop sticks 1/8 inch out of the water...

[Neil McGrath]

Weight sounds about right. The CG should be just behind the sponsons. Motor will get very hot on 1650maH cells if not water cooled. 600maH should be OK, otherwise add a motor cooling coil made from aluminium tube (2 ft of 3mm diameter wound on a broom handle former should do the job).

Neil

[Gonflyin01]

I quit on the hydro. I got a srevo wet. one of my only 2 hs 55 servos for my sky rider. It BROKE! Im mad now! :( But i put the things back in my Wal mart boat. It runs to nice to keep kept inside! :) I have my 1650 mah in my wal mart boat to. Is that to high? I do have a 600 AE pack also. My ESC gets extremely hot also, will the smaller pack slove this??

[Neil McGrath]

The 400 race is quite a hot little motor and you will need to keep the prop small to get the best out of it. If you go too big you will just burn it out. This could also explain why your ESC is getting hot. Something like a Graupner 26mm carbon fibre prop or a cut down version of one of the small Octura props should be ok.

[Gonflyin01]

okay, cool,thanks