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Author Topic: Brushless motor size  (Read 371 times)

RodgeyD

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Brushless motor size
« on: August 08, 2020, 11:39:39 am »

Hello all,


Could someone please be able to give me some advice regarding power set up?
I'm building the Aurora from Sarik plans, it's a Cygnus style fishing boat 785mm x 290mm, what I would like to know is what size brushless motor to put in. I don't want it to be slow or super fast but a nice scale speed, think it'll have a 45mm or 50mm 3 bladed prop.
Any advice would really be appreciated.


Many thanks.
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Subculture

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Re: Brushless motor size
« Reply #1 on: August 08, 2020, 01:36:45 pm »

Direct drive,or will a belt or gear reduction be acceptable?

Also voltage you wish to run at will be helpful.

RodgeyD

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Re: Brushless motor size
« Reply #2 on: August 10, 2020, 08:53:27 am »

Sorry for lack of information,  I would like to use a brushless motor ( don't know what kv , as really don't understand them ) .
Battery ! Does a lipo last longer than a SubC pack? 12v 5000mAh SubC or 11.1v 5000mAh lipo  {:-{
12v sealed lead acid wont fit in the hatch.
Belt or gear drive ! I have never used them so direct drive would be preferred.
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canabus

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Re: Brushless motor size
« Reply #3 on: August 10, 2020, 10:18:16 am »

Hi RodgeyD

A brushless motor kv is the rpm per volt, so a 3542-750kv is 35mm diameter a 42mm long and on 2S Lipo(7.2 volts) maximum un loaded rpm 5400 and on 3S (11.1volts) is 8300 rpm.

But for you size boat a brush 540 (35mm) motor would be a better.

I have two Hellen fishing boat(850mm) with 540 rock crawler 80 turn motor running direct drive( no cooling).
Motor rpm 5500( no load) on 2S.
Esc is a 60Amp Hobbywing Quicrun( with link settings for forward and reverse ONLY).
Lipo battery 2S 5000mah and the prop is a brass 3 blade 60mm.

The boats have a good turn of speed. I have them on 75% throttle each way!!

I used the Lipo because of the small hatch size.
Very easy to get the battery in and out.

Canabus
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RodgeyD

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Re: Brushless motor size
« Reply #4 on: August 10, 2020, 07:26:36 pm »

Hello all,


Could someone please be able to give me some advice regarding power set up?
I'm building the Aurora from Sarik plans, it's a Cygnus style fishing boat 785mm x 290mm, what I would like to know is what size brushless motor to put in. I don't want it to be slow or super fast but a nice scale speed, think it'll have a 45mm or 50mm 3 bladed prop.
Any advice would really be appreciated.


Many thanks.
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