Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => DC Motors (Brushed) and Speed Controllers => Topic started by: Gardener on November 15, 2018, 01:30:07 PM

Title: Speed boat Motor?
Post by: Gardener on November 15, 2018, 01:30:07 PM
any ideas for a low drain brushed motor running on 7.2v battery for a speed boat ?
Thanks
Dave
Title: Re: Motor
Post by: Martin [Admin] on November 15, 2018, 02:27:19 PM
 
"speed boat", how big.... how fast?
Title: Re: Motor
Post by: Netleyned on November 15, 2018, 02:30:48 PM
Don't think Low Drain and Speed Boat motor
gel too well <:(
Ned
Title: Re: Motor
Post by: Gardener on November 15, 2018, 03:02:08 PM
30 long not really fast
Title: Re: Motor
Post by: Martin [Admin] on November 15, 2018, 06:15:31 PM
 
Can you still get the Graupner 700BB Turbo motor?
Title: Re: Motor
Post by: Gardener on November 15, 2018, 07:29:21 PM
Will look up thanks  :-))
Title: Re: Motor
Post by: JimG on November 15, 2018, 10:21:03 PM

Can you still get the Graupner 700BB Turbo motor?


Definitely not a low drain motor.
Jim
Title: Re: Speed boat Motor?
Post by: Ken G121 on November 16, 2018, 07:59:38 AM
Hi
Not an expert on the fast stuff, I use a couple of low drains in my static dive U47 they only pull a couple a amps each and it definitely does not come up on the plane. Again no expert but I should think 100 to 150 watts per motor sounds fun and nearer 12v to keep the current lower
Title: Re: Motor
Post by: malcolmfrary on November 16, 2018, 11:17:57 AM
30 long not really fast
Hull speed for 30" is about 2.5 mph.
Motor needed to get there depends on the hull type.  A narrow one like a warship, a 385 will do fine, a broader hull like a tug will need a bigger motor because more weight of water is having to be shoved out of the way.  Then there is the quesion of using the right prop to convert the motor power into moving water to best effect.
Different for a planing hull, but that means more power to get on, and stay on, the plane.  In turn this means higher current.
But, as said earlier, speed and low current don't go together.
Title: Re: Speed boat Motor?
Post by: Gardener on November 16, 2018, 12:03:05 PM
 :-))