jae mini sprint, can I use a watercoolded inrunner??

[crudeau]

So I'm looking to go with a JAE mini sprint. When I order it I want to get the esc/motor/battery from hobbyking at the same time. Is there any reason I can't go with an inrunner and water cooling? I'm trying to search but not really finding to much. Maybe someone can link to a build where he used a water cooled esc and motor. Also so far I know that I want to build it with some thicker boom poles, any other pre build tips?

[Fluid]

I would recommend building as per the plans, it will work great. The last one I saw used the outrunner and was built to plans, stiffer booms may work against you. Not a lot of room in there for water cooling lines etc. I have seen a couple larger JAEs which were "customized" by the builder, neither ran that well.



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[martin]

http://www.youtube.com/watch?v=nOUlQEGC8lg
Their you go, Mini Sprint with watercooled 60a esc but still with a $12 outrunner motor & uprated 6mm boom tubes. Boat now has been fitted with a Leopard watercooled inrunner & 120a watercooled esc but tub was raised for more room as i use 3s.

[martin]

If your going to push the speeds on a Mini Sprint kit & do sharpe turns then use the full metal bracket on the rudder mounting bracket & not the stock wooden bracket. I also come off of the metal bracket with a doubler plate along the side of the tub, if you dont strengthen this area then youll tear the rudder of in a turn. Ask me how i know. Like Fluid said though build as per instrutions if its your first one & youll have a cracking little hydro & mod things later or with another build when you know more about riggers.

[crudeau]

Sounds good I will stick to the recommended plans. I don't however want the wood look Is paint tge best option or a thin fiberglass layer then paint? I would like to do the metal rudder support though. So I don't have to rip the hull apart latter in its life

[martin]

Most coat the hull with inside & out with epoxy resin then rub down nice & flat then paint. Another simple mod that also improves performance & stops repairs is to either bolt the turn fin right through the sponson or some put inserts into the dowl & fix into otherwise you can tear the screws that go into the wooden dowl out. Also add a doubler plate to the fin that stiffens the fin & gives better handling over a fin that has some flex in the turns. By the way no need to paint the inside just leave with a couple of coats of resin.

[crudeau]

Good tips thank you.

[Cheetahmk7]

Hi Martin,

I'm thinking of building a Mini Sprint with a 28 series Leopard Inrunner and a perhaps a 3s. Do you have photos of your rudder and turn fin modifications, or the battery/motor/ESC layout?. Did you make a taller tub, or just raise the cowling?

[Alexgar]

how much bigger is this that a renegade rigger im building one but had one on a 26x24mm outrunner 2600 kv and on 3s it was insane but the size limitations of a high c 3s offered some problems in runtime area so now looking for a longer more slim lipo that fits my needs

[Alexgar]

this was the motor
http://www.milehighrc.com/brushless400DFA.html

[Alexgar]

i have had good luck with this series of motors in the hk heli motors section i run this in minicat velocity cat on 4s and its in the mid 30s the have other kvs for other applications but the 50 amp max needs a bigger esc and bateries if this helps
my motor
http://www.hobbyking.com/hobbyking/store/__11174__Turnigy_450_H2218_Brushless_outrunner_250 0KV.html
my esc water cooled and waperproofed
http://www.hobbyking.com/hobbyking/store/__10013__Hobbyking_SS_Heli_Series_50_65A_ESC.html

motors i may run in a little bigger 3s rigger
http://www.hobbyking.com/hobbyking/store/__11178__Turnigy_450_500_H2223_Brushless_outrunner _3500KV.html
or
http://www.hobbyking.com/hobbyking/store/__11172__Turnigy_450_H2218_Brushless_outrunner_355 0KV.html

[martin]

[QUOTE=Alexgar;435932]how much bigger is this that a renegade rigger im building one but had one on a 26x24mm outrunner 2600 kv and on 3s it was insane but the size limitations of a high c 3s offered some problems in runtime area so now looking for a longer more slim lipo that fits my needs[/QUOTE
Take a look at Thunder Power lipos they offer very slim but longer lipos than most do, from memory they do a 2700mah 3s thats only 21-22mm deep. TP are not cheap but their one of a couple makes lipos that are the best around. These are 65c - 130c by the way.

[martin]

The tub on mine was raised to 2" loads of room for 3s + Seaking 120A watercooled esc & can go up to Leopard 2860 motor. If nessasary at a push i can get a TP 3s 3300mah in, the idea for raising the tub a bit more than i needed was to fit 4s at a later time. I dont use the cowl as i prefer 2 separate smaller flat hatches as their better to seal + i only untape 1 to change the battery each time.

[martin]

http://www.youtube.com/watch?v=nOUlQEGC8lg
Eric this is my stock Mini Sprint before i modded it with higher top & larger 6mm boom tubes. This is with a cheapo $12 motor, motor was Mystery 2836 - 3800kv on 3s 60c 2200mah & Octura x435 detonued & back cut. Should be much faster with the new Leopard motors.