Model Boat Mayhem

Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: sigfortunata on September 15, 2016, 12:57:37 pm

Title: Which motor for a good performance?
Post by: sigfortunata on September 15, 2016, 12:57:37 pm

I am building a 33" Lesro Pilot boat which I plan to power with 2 brushless motor on either 11.1v or perhaps 14.8v.


Its quite a big boat and I am not bothered about scale speeds, I want it to be quick off the mark and able to plane well.


I have a workable understanding of kV to volts to rpm and that the higher the number of turns generally the lower the kV but the greater the torque.


I have narrowed it down to a choice  of 2 Outrunners   (I don't want the faff of  having to cool motors etc)


Turnigy D 3542 6T 1000kV


Leopard LC3536 8T 960kV


Which would be the better choice or is their nothing in it (Or am I really wide of the mark????)


Steve

Title: Re: Which motor for a good performance?
Post by: canabus on September 15, 2016, 01:20:23 pm

Hi sigfortunata

The D3548/4 1100kv is a better motor with 910watts and handles 3-5S Lipo batteries on a 60 Amp ESC.
I am using the Hobbyking car ESC with reverse(HK-60A SL) with this motor in a 34" Sea Commander.
Prop is a 2 blade 40mm.
I am not using any water cooling system and 1/2 hour of high speed motor and ESC only warm.

Title: Re: Which motor for a good performance?
Post by: HMS Invisible on September 15, 2016, 04:13:58 pm

 For those that have no understanding of the turns, KV & torque relationship it should be mentioned that torque is the same if you keep voltage in proportion to turns through three KV options of each of the two motors listed.
 If you need more torque you need a completely different motor, not the higher KV option as that has the same effect on rpm and rotor torque as lowering the voltage.

Title: Re: Which motor for a good performance?
Post by: sigfortunata on September 15, 2016, 04:40:17 pm

I thought if you wanted more torque you require less kV and more turns motor ? (wish I had paid more attention in physics!!)


So back to my original query, are those motor suitable for my Pilot boat requirments?


S

Title: Re: Which motor for a good performance?
Post by: boatsdelboy2 on February 07, 2018, 05:47:55 pm

Hi,
     I have a 24 inch pilot boat and would like advice on size of motor prefer outrunner

Title: Re: Which motor for a good performance?
Post by: tobyker on February 07, 2018, 09:25:24 pm

I have a 24 inch MTB and it seems to be going very well with a Hobbyking "Funfighter" 2825-1950KV. I understand it is their replacement for an aircraft motor. At present I'm running it on a NiMh 7.2v car pack but aim to go to 2 or 3 cell LiPo soon. The prop is an x30 but I'm putting an X35 on as my mate Steve says the motor isn't doing any work at present.

Title: Re: Which motor for a good performance?
Post by: john44 on February 07, 2018, 09:28:42 pm

Hi Steve you haven't stated what size and pitch of prop you are thinking of using.


John

Title: Re: Which motor for a good performance?
Post by: canabus on February 07, 2018, 10:49:20 pm

Hi Toby
If the motor and ESC handle 3S(11.1 volts) you will pickup about 7000 rpm.
Stay with the 30mm prop, brushless motors like to rev and to bid a prop cooks motors and ESC.

Canabus

Title: Re: Which motor for a good performance?
Post by: boatsdelboy2 on February 08, 2018, 11:52:07 am

Hi thanks for the info just getting started on mayhem and finding my way round thanks again
Dave