Model Boat Mayhem

Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: reaperspear on April 19, 2012, 11:02:57 am

Title: Pairing brushless motors,esc,s batteries and props.
Post by: reaperspear on April 19, 2012, 11:02:57 am
  Hi, Could anybody suggest a setup for a boat I have built from the plans of a pt109, just changed the topsides. It is about 33 inches long and I would like to power it with two brushless motors and it would be nice to go up on the plane. I wonder if I need two watercooled esc,s and watercooled motors while trying to keep the cost down.
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: Mad_Mike on April 19, 2012, 11:19:07 am
you know if you get the prop right you can stick with the standard 540 motor. i got the same boat as you:

http://www.youtube.com/watch?v=CEBLJ757JA8&feature=channel&list=UL

what batteries are you using at the minute?


if your dead set on brushless ill find something for you
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: Mad_Mike on April 19, 2012, 11:33:00 am
if you go dual brushless youl need 2 speed controllers.

to keep it simple use 2 of these:

http://www.ebay.co.uk/itm/2100-Water-Cool-Brushless-Motor-SEAKING-60A-ESC-CA060-/250866926121?pt=UK_ToysGames_RadioControlled_JN&hash=item3a68d58229

and then power them by this:

http://www.hobbyking.com/hobbyking/store/__17252__Turnigy_nano_tech_5000mah_2S_35_70C_Lipo_Pack.html

youl need a balance charger to charge the lipo

if you use an nimh battery you will need 2 of them one for either motor. 1 battery driving 2 motors will overload the battery, but the downside to two batteries is the excess weight.
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: reaperspear on April 19, 2012, 11:50:32 am
   Hi Mike, I was considering using two 1500 mah 3s in parralel, the props I have that I thought I would use were from cornwall model boats ltd ( part numbers g2298.40rh and lh )
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: Mad_Mike on April 19, 2012, 11:51:50 am
if you dont mind a bit of engineering you can use 2 of these:

http://www.ebay.co.uk/itm/RC-Hobbies-2200KV-Brushless-ESC-30A-Motor-Outrunner-2212-6-/290696984628?pt=UK_ToysGames_RadioControlled_JN&hash=item43aee3f834

2 of these:

http://www.ebay.co.uk/itm/HOBBYWING-Seaking-35A-Brushless-Water-Cool-ESC-RC-Boat-EC059-/110838498457?pt=UK_ToysGames_RadioControlled_JN&hash=item19ce7d4499

and that same lipo battery as before.

Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: Mad_Mike on April 19, 2012, 11:57:34 am
if you have 3s lipo then ill need to possibly find  a drop in the kv.

http://www.ebay.co.uk/itm/S2208-1800kv-Brushless-Motor-Outrunner-RC-Plane-/380387245760?pt=UK_ToysGames_RadioControlled_JN&hash=item5890d8bec0

Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: reaperspear on April 19, 2012, 12:00:58 pm
  Hi Mike, those motors seem to be up my street but do you think I would need to cool them.
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: Mad_Mike on April 19, 2012, 12:09:37 pm
the inrunner motors have a cooling jacket build in. the outrunners dont and harder to water cool. If you get the motor and prop combination right then water cooling isnt necessary. Still watercool the speed controllers thats a must. The props you have selected are way too big. if you stick with the 540 motor then youl need this prop:

http://www.astecmodels.co.uk/catalog/product_info.php?cPath=25_50_59&products_id=350&osCsid=2d0bcfbcbfbf9760b23d4ba2e3062b43

if you go down the dual prop 3 bladed route you can use the 30mm diameter ones on either of those motors.
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: reaperspear on April 19, 2012, 12:21:49 pm
  Thanks Mike you have given me pleanty to think about, catch you later.
 
Title: Re: Pairing brushless motors,esc,s batteries and props.
Post by: essex2visuvesi on April 19, 2012, 01:31:39 pm
A watercooled motor mount is about the best you can do with an outrunner

Some of the outrunners designed for heli use actually have a cooling fan built in, this coupled with a watercooled mount should be sufficient.
Also bear in mind that the quoted specs (amps etc) are for spinning a prop in air and that using them in boats the current draw can be somewhat higher