Added brush cooling to my 700SC motor. Soldered approx 1" long brass tubes, across brush leads on the motor, connected them with fuel tubing, and plumbed them into the line that water cools the esc. Still think I might add a cooling coil to the motor can. It gets pretty hot after 2 minutes of full throttle with lipos. No where for the heat to go with it sealed up tight as a drum in there.
I got my speed vee 800 boat all set to hit the local pond, just waiting for the wind to die down. I update the speed control with a waterproof one from proboat, very nice no setup required and good down to 15 turn. Zips in the bath tub. I updated the drive with stainless bearings instead of bushings, I even found a drive shaft at the hobby store. WHat do different props do. The boat even has spektrum, can't wait to go out and enjoy the weather. Way to warm to be racing inside and theres no a/c.
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Hey do you guys know what people are for drag boats now??? Like Batts, Motors, Etc???? I have my boat I made like 10years ago and when we ran back then we ran 18cells and 3turn motors so any updated info would help because my son races the cars and now they have Lipo batts and brushlees motors!
The prop needs to match the characteristics of the motor, rpm and torque, and the speed the hull will achieve. Not enough prop and you aren't going fast, too much prop and you overheat the motor, draw too many amps. Its some math and science that I do not yet understand.
As for the drag boats, lipo and brushless are taking over everything, including boats. Its only the classes that are limited to brush that remain brush. LSH for example. I might have spoken too quickly about lipo. It looks like many classes still use a specified # or range of # of nimh cells. If this is some official competition and not just having fun, you'd better check out the local rules.
Chewie, I just added a liposhield cutoff from Dimension Engineering. It will scale down the throttle if you get to 3.0v/cell. Its cool, it has a led that blinks out the # of cells when you hook it up to power, so you can confirm it knows the correct cell count. I won't rely on it, but it doesn't hurt to have an extra safeguard against over discharging the lipos. I wired it into a deans connector, so it just plugs into the battery harness and I can move it to another vehicle if I so desire. The esc plugs into it, and it controls the signal to it if you run down too low on voltage. Hopefully I can find time to test it and the brush cooling tonight. I like to tinker. I might still add a cooling coil to the motor just for fun. Can't hurt to keep the magnets cool as possible.
I just got back from running my boat the first time. It was very fun besides picking the seawead out. My first boat was a nitro miss bud. and it just pissed me off all the time. I like electric far better. Will running today the motor did get warm, so I made a homemade cooling coil with stuff from the hardware store for $2.50. It should work pretty well.
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I like electric as well, because of the ease of use. Flip a switch and it goes. I fly electric planes as well and its the same story. With good lipo's and a brushless you have lots of power. I'm ready to fly a big gas plane for the first time and I was surprised how well the motor runs and how easily it starts. I might be able to be converted. However, they'd never let me run a nitro boat in our local pond. Too much noise and the I'd get complaints about contaminating the water.
Whats the warmest a motor should get in a boat, mine is around 125 after a run.
If that's 125 degree fahrenheit, no problem. 125 celcium and you are too hot. Unscientific field method of testing is, can you hold your thumb on it for 5 seconds? If not, its too hot. Heat suggests problems like over gearing (or over propping) and it also can cause damage to the brushes, commutator, armature and weaken the magnets.
. I updated the drive with stainless bearings instead of bushings, I even found a drive shaft at the hobby store. WHat do different props do. The boat even has spektrum, can't wait to go out and enjoy the weather. Way to warm to be racing inside and theres no a/c.
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