Thread Tools
Jan 29, 2013, 06:58 AM
Maritime
KM.Racing's Avatar
Discussion

Large Brushless DC Motor Suggestion


Hello Boaters

please need suggestions about a large dc motor that can pull a

Vee Hull
-280 cm length
-120 cm beam
-200 Kg Weight
and having a speed of 35 mile

thank you very much ! I'll bring some pictures for the hull soon .
Regards
Jad
Sign up now
to remove ads between posts
Jan 29, 2013, 01:57 PM
Registered User
wparsons's Avatar
At that weight you'll probably be much better off with a gas engine, that's about the size of a seadoo.
Jan 29, 2013, 04:38 PM
Maritime
KM.Racing's Avatar
Quote:
Originally Posted by wparsons
At that weight you'll probably be much better off with a gas engine, that's about the size of a seadoo.
Wparsons my friend the idea is using a complete rc system instead of a gas engine
I'm studying the problem for now running a small boat on dc motor
Jan 29, 2013, 07:52 PM
Registered User
wparsons's Avatar
You can still have a complete RC system when using a gas motor.
Jan 29, 2013, 09:27 PM
RELAX. You'll live longer
785boats's Avatar
It all depends on what voltage you intend to run as to which KV rating is suitable.

This might be enough. 12,000w. Available in various Kv ratings.

http://shop.rcboatbitz.com.au/index....ort=20a&page=4

Then there's this one perhaps. 23,000w, if you've got deep pockets.

http://shop.rcboatbitz.com.au/index....oducts_id=1057
Jan 30, 2013, 08:00 AM
Maritime
KM.Racing's Avatar
Quote:
Originally Posted by wparsons
You can still have a complete RC system when using a gas motor.
I want to run the boat on electric system only .

Quote:
Originally Posted by 785boats
785boats
ohh god the 23,000w need input voltage between 33 and 170 v from where should I bring all this voltage ! :O
I'm thinking about running the boat on 36~48V and any suitable KV

Question !
can I ran this kind of motor on a Boliden battery 100 A ?or above
or just lipo is required ?

Thank you guys
Last edited by KM.Racing; Jan 30, 2013 at 02:50 PM.
Jan 30, 2013, 12:29 PM
Registered User
wparsons's Avatar
If you want 12000w on 48v you would be drawing 250a constant, if you wanted 23000w on 36v you would need 640a constant.

If you want to run relatively lower voltage, you will need a lot more amperage to get the wattage needed to make the boat move.

23000w is only 30hp, is that enough to move a boat that size/weight at the speed you want?
Jan 30, 2013, 01:09 PM
P31
P31
Registered User
Jan 30, 2013, 02:55 PM
Maritime
KM.Racing's Avatar
Quote:
Originally Posted by wparsons
If you want 12000w on 48v you would be drawing 250a constant, if you wanted 23000w on 36v you would need 640a constant.

If you want to run relatively lower voltage, you will need a lot more amperage to get the wattage needed to make the boat move.

23000w is only 30hp, is that enough to move a boat that size/weight at the speed you want?
wow that's really a big number of Amps ! in this case I need a power plant for my boat :P

yeah 30 hp is my purpose but I'm still thinking if this motor is able to move the boat , but I'm afraid of the drawing A :/
Jan 31, 2013, 09:48 AM
Registered User
wparsons's Avatar
It's roughly 765 watts per HP, and volts * amps gives you watts. If you know how much hp you need, then you can calculate the watts, volts and amps needed. Keep in mind that my calculations assumed the motor is 100% efficient, which it won't be.

If you want to keep the amp draw around 100a you would need 230v+ to get 30hp.
Jan 31, 2013, 02:49 PM
Maritime
KM.Racing's Avatar
Quote:
Originally Posted by wparsons
It's roughly 765 watts per HP, and volts * amps gives you watts. If you know how much hp you need, then you can calculate the watts, volts and amps needed. Keep in mind that my calculations assumed the motor is 100% efficient, which it won't be.

If you want to keep the amp draw around 100a you would need 230v+ to get 30hp.
wow !!!! it's impossible to get 230v+ !
any way thank you wparsons for your help I really think that the gasoline motor is 100% successful for that hull then the dc motor
Jan 31, 2013, 08:07 PM
Registered User
Amp Abuser's Avatar
Motorcycle engine DD -say a 250cc should do it. Ninja 250R makes 30HP@10500 rpm. 2blade 5.5Dx6P would be a good start for speed. Do a search for Ron Hill he designs and makes race props and can make to suite rpm / hp at the prop to reach 30mph.
Feb 03, 2013, 08:16 AM
Maritime
KM.Racing's Avatar
Quote:
Originally Posted by Amp Abuser
Motorcycle engine DD -say a 250cc should do it. Ninja 250R makes 30HP@10500 rpm. 2blade 5.5Dx6P would be a good start for speed. Do a search for Ron Hill he designs and makes race props and can make to suite rpm / hp at the prop to reach 30mph.
thank you for your suggestion


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question ESC for large dc motors badmoonryzn Electric Plane Talk 10 Dec 14, 2015 01:38 PM
Help! Asking Help: Using a large dc motor as a servo. monkguy DIY Electronics 9 Oct 10, 2010 09:16 PM
Large Scale Motor suggestions Chris Cheyne Power Systems 6 Sep 22, 2004 12:48 PM
Cool DC-3 Motor suggestions?? ericamadio Power Systems 2 Aug 31, 2004 07:41 PM
Suggestion For A DIY Brushless DC "Radial Engine" blue_bull Scale Kit/Scratch Built 0 Feb 25, 2004 01:46 AM