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[lee5505]

Hi folks,

I'm fairly new to this game and after some advice please, I have just picked up a 40" sport Catamaran hull as a project, with twin Johnson 650 motors and Graupner running gear, the motors are apparently 12 Volt, 30,360 RPM High Torque.
I need to match these to a ESC and a suitable battery.
Could I have some suggestions for ESC & battery... I was assuming that LIPO would be the way to go with this?  ESC water cooling provision in place if needed?

Thanks in advance for any help you can provide with this.

Lee

[MikeA]

got any pics? has it got 2 prop shafts and props aswell?

[lee5505]

Hi Mike,

Yes two propshafts, I will measure the props and update.
It looks the the previous owner was running a single esc as motors wired together, but having looked at pics of other twin motor fast electic boats it seems like some people are using twin esc's??
I will take some pics and try to post them.
Thanks for your help.

Regards

Lee

[MikeA]

you need either twin 30 amp esc's or 1 60 amp esc. In my oppinion i would iliminate the use of reverse and use two of these:
http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idproduct=6468
 there forwards only because there aeroplane escs but there the size of a 10p and very light. however you need to modyfy the throttle on your transmitter so neutral is full reverse. like on a aero transmitter. each esc with need a 25-30amp fuse in the positive. batteries though well youl need a high mah one with a high discharge rate. do you want to use lipo or nimh?

[lee5505]

Thanks Mike.
I guess I don'y really need reverse for this kind of boat.  Is there any advantage to using two 30amp ESC's over one 60amp?  I'm just trying to get my head around it...
I don't have a preference really over lipo or nimh, I just assumed that everything was going towards Lipo these days??  Advice/opinions will be greatly apreciated...

Regards

Lee

[MikeA]

well the advantage is of using 2 esc is that if you lose 1 drive cos you still got the other one to get home. you will need to set up the escs like this:
http://www.westbourne-model.co.uk/images/help/wiring-Twin-motor-twin-Esc-nicad.html
you will need to disable the bec on one of the esc's you do this by either cutting the red wire on the y lead or you can take the pin out of the esc's plug.



Nimh batteries are cheap and easy to charge with a standard wall charger. but they are quite heavy and the higher the mah the heavier the battery. Lipo's a are lighter have a higher discharge rate and charge very fast. But they are expensive and MUST have a balance charger to charge them to avoid exploding which is also not cheap.

[lee5505]

Ah I see, I'd never even thought about that!
Thanks for your advice and useful links, looks like I have some research & shopping to do then!!

Thanks again,

Lee

[MikeA]

i have to tell you though about those esc's that the neutral position is reverse on ya 2 channel controller. so you have to either make the spring rest at fully reverse or remove the spring altogeather. i have a trigger type transmitter and i opened it up put a screw in it and now the trigger is fully forward.