water jackets on brushless?

[painly]

i've been doing water jcakets on my 700's and am VERY impressed with there performance, and cant thank rum runner enough for the how-to article. However ive took the plung to brushless, and have myself a b50 9l im going to be running on 12-14 cells, i know brushless have a bad tendency to store internal heat, and i was just wondering if it would be more benificial to make a water jacket for my motor rather then just slap a cooling coil on it? thanks

[J Solinger]

Although a cooling coil is better than nothing, a good water jacket is much better than a coolingcoil. I like jackets, they are simpler, more effecient at heat removal and can be a weensy bit lighter.

[Jay Turner]

...have myself a b50 9l im going to be running on 12-14 cells Note that with a Kv of 2683 rpm/volt that 9L will need a very small prop to run on 14 cells. That's 45,000 rpm with a cell voltage of 1.2 volts. Even at a very high amp draw on 12 cells you'll still spin ca. 35,000 rpm. For a gear drive or a rigger it may work fine, but that's a lot of rpm for a sport boat. A 9XL would be a much better choice - perhaps the 9L was a typo. :(

[painly]

thanks for the replies, and no, that wasnt a typing error. i was thinking a 40mm prop on 14 cells, the 42 works good on 12. maybe even something in the 30's. THe boat its running in is a 24in mono. I usually run it for about 1-2 mins before i give it some time to sit and cool in the water.
thanks

dont 9xl's usually run cell count into the 20"s?

[Jay Turner]

Not in direct drive, unless for SAW speed events. On 24 cells the rpm is in the 40,000 rpm range, 'way too fast for a direct drive oval setup.

[painly]

ok

but am i way off using a 37mm prop on a 9l with 14 cells?

[Andrewg]

Painly

a 9L will run best on Y536 or X438 - at those pseeds you should get a reasonble runtime and better speed.

The fact you stop after two minutes is proabbly saving you from damaging your cells irreparably

In Europe 5-6 minutes runtime at race speed would not be unusual.

[painly]

ok so a 1.4 38mm prop for 14 cells? the hobby shop who i bought the stuff from told me with the small light boat its going in that a k42 (im guessing 1.6) would be a good try. also i have NO WAY of getting props here, so is there anyway to skim a prop if 42 is way too big? i know a guy here running the same 12 cell setup i was going to and he gets pretty hot after about 5 mins of running, mind you his boat is 27in deep vee, and mine is 23 1/2. shallow mono (much like the flat bottom el lobo except a bit shorter). also do you or anyone else know any good places in canada that stock props? climate only has the 42, and everywhere else in the states wants 7 bucks shipping, although im sure they could go small packet air for next to nothing, they have their shipping rates usually set in stone.

thanks.

[AndyKunz]

Where is "Stoon?"

Andy

[painly]

saskatoon saskatchewan canada.

broke a drive dog yesterday, so i think im gonna make an order anyways. should i be get in addition to my 42 mm prop a 38 and 40 l.6 or 1.4?

thanks

[funrunner]

I did a search for Saskatoon on RumRunner and see that I'm not the only one here in Saskatoon running R/C electrics. I'm running a Hydromite made with plans from microhydros.com. My hardware is all home made and for power I'm using a Megmotor 16/15/5 w/2100mA Lipo battery. I would like to hear from you. Are you still boating?

[Peter Zicha]

A little late though , painly's already grown up and had grandkids since his last post here......LOL . hey farmboy hello from Alberta and welcome to the forum..................:wave:

[funrunner]

So it seem I’m all alone again. Not quite last year I help a friend into boats and this year hopefully a couple of more. In order to get more interest, I've taken on getting the material and parts laser cut for 10 RC boats (6-Hydromites and 4 Deep-Vee's) 7 of them are sold to friends and I'm building the remaining 3. I can only hope that the others will get built. Last year I built my first Deep-vee made with my own drawings. It turn out really nice, painted it orange and white for my daughter so she has her own boat when we go out to the pond. The Deep-vee’s that were just cut a scale down drawing of a gasmono to 21”. The original plan was around 43”. I have the hulls built up already and water sealed, just the deck and then the decision of the power plan to use. Likely it will be the Meg Motor 16/15/4.
So what are your interests? I’ve been flying RC for over 12 Years and running boats for the last 3 years. Lots to learn, but they scream along now. :)

[Peter Zicha]

Interests.....

Boats
electric motors
computors
Quading
machining

I have been tinkering with remotes since 1982
go to youtube and look up my profile.......http://www.youtube.com/user/Titanis2000 a few of my boat runs and my taig lathe , I am going to order a taig CNC mill in about 2 weeks also and am in the process of building a Neu 2230 powered 48"inch nitro killer , its in the offshore forum under 2230 stealth................Enjoy..:yeah: