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Author Topic: LONG RUNNING TIMES ON BRUSHLESS MOTORS  (Read 10990 times)

Garabaldy

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #25 on: October 15, 2008, 12:14:45 AM »

if we are onto brushless oops admissions i tested the starboard drive out but had forgotton to lube the shaft and i have clearly damaged the sintered bearings due to friciont/heat build up.  The motor didn't break a sweat doing this either. 

Now, how do i replace the sintered bearings? %%
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Weeds

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #26 on: October 19, 2008, 03:50:04 AM »

Sorry for off topic question,

Can I use my TowerPro Brushless Outrunner 2410-08T 890kv http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=664 in a boat, and if so, how?
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Martin [Admin]

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #27 on: October 19, 2008, 04:34:04 AM »

Almost any motor can be used in a boat, just a matter of mounting it, fitting the right speed controller,
connecting it up to a shaft
and selecting a suitable propeller.... simple as that!

I don't really understand brushless motors numbers yet but the TowerPro Brushless Outrunner 2410-08T 890kv at $7 is
so cheap,  it's worth a punt just to experiment! As it an outrunner (the whole outer casing spins with the shaft), the
inner bit, (coils) is the fixed bit and also the mount mount. The motor is therefore fixed at the tail end, not the front end
like we're used to.  It's not a big motor and designed for ultra, ultra light RC planes so it won't have much guts but should
be ideal for a small speed boat, say 12-18" long. The trick is to find the right propller to match the motor.... trial and error...
.... unless anyone knows a good match?




My mate Bradders took a punt on one on fleabay - 20 with ESC!!!!! He's going to use it in a small balsa hydro he's building.
Item number: 230301512227        

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nick_75au

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #28 on: October 19, 2008, 09:11:00 AM »

That second motor is the same as the one I run in my Springer, I think it might be a little slow unless you really up the voltage to the maximum the speed control can handle. It Spins a 40 mm Raboesch prop on 12volts with a current draw of around 20 amps but is spinning that prop at 11000 rpm. At 6 volts it draws 3.5 amps but is to slow for the Hydro methinks. A fellow on another forum did not have a great deal of success with the first motor in a small PT boat hull.
Regards
Nick
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andrewh

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #29 on: March 04, 2009, 12:54:42 PM »

I have been searching for this thread/post for weeks :}

Weeds- this is the "bell motor" that has been powering my Brushless trial boat
http://www.modelboatmayhem.co.uk/forum/index.php?topic=14068.0

Using a Graupner s29 racing prop (2mm thread)
and working very well in my Higgins PT boat on 6 and 8 cells, 35mm 2-blade Graupner prop

Because my version is a 21T wind of about 1200KV, and the one you pictured is 890KV you need a bigger prop - probably 40mm - see what happens

Martin sed:
It's not a big motor and designed for ultra, ultra light RC planes so it won't have much guts but should
be ideal for a small speed boat, say 12-18" long

All true, but this one will swing a 10x5 prop and produce 120watts - about twice what a S600 is comfortable with

The PT boat is 30 inches long, but not heavy


THIS is that it does in a 12 inch sillyboat


so well worth a try!
It needs any cheap 10A or 15A brushless ESC
It also sings as it runs - the rotor doesn't look like a bicycle bell for nothing :}

andrew
late, but pursuing

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boatmadman

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #30 on: March 04, 2009, 03:43:32 PM »

This is all very interesting, I wonder if the ACTION man is planning an expansion into brushless?

Ian
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andrewh

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #31 on: March 04, 2009, 04:45:05 PM »

Ian,

You could ask him :}  but I don't think so at the moment (altho' I would NEVER presume to outguess a modest genius)

I have had many comments on the installation of the motor in the PT boat - with comments ranging from "kinda Puny" to "cheap" but its like a lot of things - the size (relative to brushed motors) is not relevant  - what matters is the revs, torque, what props it will twist at what speed. 
The entire installation cost me 20 several years ago, and could now be bought for half that, or about the price of a S600 from a "branded" source,
andrew
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sunworksco

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #32 on: July 20, 2009, 08:09:19 AM »

I'm using two Novak Crawler brushless motors and ESCs in my 1/32nd scale Type IX-C sub(2400.3mm long).These motors are the sensor type with programable low/high speeds and can run the prop at very low scale  rpms with very cool performance.The motors are about the size of brushed 380 motors,do not cause noise interferrence,are energy misers and outlast brushed motors.They are more water resistant as well.The ESCs can be water or air/fan cooled. I'm also using some very nice linear servo adaptors for the rudder and diving planes.8)
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gyronuts

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #33 on: September 14, 2009, 10:02:28 PM »

Hi,
    Anyone tried brushless on a 12v dry cell in a precedent perkasa 49" boat with a single prop? thanks. Bill
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debssnal

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #34 on: September 16, 2009, 07:54:05 PM »

Hi Bill,

One of our club members done it but it was twin prop. It was going around the lake just on the props.
Went very very fast. If you give me the weight and the size of the propeller I will send you a link with the motor you need.

kind regards
Alan

p.s failing that, come and see me at the Southern Model Air Show at the weekend. Just ask for Alan the Marine coordinator
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ray123

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #35 on: September 17, 2009, 07:37:06 AM »

ive done it 2 600kv brushless motors on  a 12volt 4amp jell cell  lasts about 6min's  but in retern you got speed  :-)     (the only thing is my boat isnt a true planing hull  so going this fast i couldnt turn it very well %% (as good as brushless are ive decided to go back to 540s & i get 10mins plus run time!!) ;)    i have 2 brushlees motors & speed cons i might sell now!  only used 6times   regards ray
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andrewh

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #36 on: September 17, 2009, 12:52:35 PM »

Ray!

Its not the Brushless motors that are eating the amps  - its the props!

At every point of operation the BL motors are VERY much more efficient than any Brushed.  If you change you are giving up the efficiency.

Reduce the prop size or pitch (or both) until the run time is what you want and it will be going very much faster than with the Brushed motors (because of the efficiency)
If the motors are 600kv and the boat is really moving the props must have a big pitch so they must have a fair diameter (cos the two are related in boats (not in aircraft)) so I suggest trying some cheap plastic props

hope this encourages you
Pm me if you would like to discuss
andrew
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nick_75au

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Re: LONG RUNNING TIMES ON BRUSHLESS MOTORS
« Reply #37 on: September 19, 2009, 02:17:17 AM »

Ray
I aggree with andrew to a point, its the rpm of the props, double the rpm of the prop and the power absorbed quadruples, the brushless motors are able to spin the props faster and handle the power but draw more current in the process,

Drop your voltage to 6-8 volts and come back with your results

Nick
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