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[RyanB]

I have read and read and read info and forums about brushless motors but can still not work out what I need! Please can someone help me, I am running a speed 600 with a 15 amp esc. I want to change to brushless to gain more speed. Can someone tell me what a swap would be, ie, what motor and esc. I have looked on giant cod but still non the wiser!
Cheers Ryan

[nick_75au]

Which speed 600, what voltage, what boat, what size prop, surface drive or submerged drive but......

say its the middle of the road speed 600 BB 9.2 volt, it has a Kv of 1700 approx and a nominal watts of around 120 or so, a 36 mm diameter in-runner of similar Kv will give you more speed and be able to handle any prop you could throw at a 600, get a 30 - 45 amp esc and you should be set. Don't be tempted to increase the Kv by a great deal, you will find the same Kv will be faster with a brushless due to the 36 mm motor running at a higher on load RPM.

Nick

[RyanB]

so would this:

http://www.giantcod.co.uk/bs2845-2100kv-inrunner-motor-p-404990.html

and this

http://www.giantcod.co.uk/hobbywing-seaking-marine-reverse-program-brushless-p-403646.html

work?

Cheers Ryan

[barriew]

That motor is a 28mm one. Nick suggested a 36mm one, so this is about the right KV

http://www.giantcod.co.uk/black-mantis-bm3660-1900kv-inrunner-brushless-motor-p-404998.html

Barrie

[RyanB]

Is this just the size o the motor and wouldn't hurt to use the one I suggested, the latest one runs on 9v and I am running 7.2!

[AlanP]

The motor that you have picked Ryan (2845) would be OK but the speed controller that you have picked is a little on the small side, the motor takes 40 amps under load and the esc you have picked is a 35 amp, not a good combination, you need to go for at least a 45 amp esc water cooled if it is inside the boat.

Just my thoughts
Alan

[nick_75au]

Again, really need to answer the questions I asked to give an educated answer ,

The motor and esc will work for some set-ups but I cant answer whether it will work for yours.

Cheers

Nick

[RyanB]

Sorry Nick, The set up is a graupner speed 600 eco running on 7.2v. The boat is the shamrock as pictured in my profile pic, I would consider it to be a fast (ish) patrol boat around 25 to 20 inch long. The prop is 35mm P style which is submerged… Hope this helps my issue…

Once I have worked out what will work in this boat I will then have more of an idea what I can convert my other boats too.. I don’t know why I cannot full understand this brushless game but I am sure it will all click into place at some point..

Thanks for your help,

Ryan

[nick_75au]

The 600 Eco has a Kv of around 1500 Kv, don't use a 2100 Kv, it will be too much, I would stick with below 1700 Kv, and the 28 mm motor will be enough with the 35 mm prop.  Expect about 10 -15 amps running current so a 30 amp ESC shroud be enough regardless of what the motor specs claim. The prop causes current draw so if you put a 40 mm prop on the current will go up.

Nick

[red181]

how heavy is the boat?

I would suggest very similar to nicks recommendations, I have some brushless setups, I would probably suggest staying around the 1000 kv or maybe a little bigger,1200,  and go outrunner as they cool better.

My fastest runs a 1620kv motor. Think of it this way, lower kv equals more grunt, and higher kv is more revs, you have to get a balance one against the other. My 1620 kv on direct drive is all revs and no go, I run it with a gearbox 2.5:1 ratio, which then reduces revs, and increases grunt, for acceleration, also, lower kv means you can swing a bigger prop, as the motor has more torque and therefore increase thrust.

Giant cod are out of stock on most motors, and have been for ages, so you might have to wait for new stock. Also, you have to consider the wattage. Unfortunately there is no defined set up, you are considering batteries, motor, esc, size of prop, size of boat, weight of boat, so many variations, its not just the motor that gives the performance, there was a post a few weeks ago and I cant find it, A chap had built a nice boat, and video with a phone I think, it was his first attempt, it ran rweal nice, and was a similar boat to yours, with a gaint cod motor, if someone could remember what it was it will probably help your decision!

Paul

[red181]

http://www.modelboatmayhem.co.uk/forum/index.php?topic=28717.0

this is what I was referring to, sorry, I forgot it was twin motor, so maybe go for a bigger motor, but similar kv?

[RyanB]

Hi guys,

just a thank you for your help, think I am getting a better understanding of all this now..... I will keep you informed once I find one I think fits the bill...

Cheers Ryan