New brushless outrunners from Hobbyking

[Guest]

Hobbyking have just released a range of new motors that should prove interesting to us guys. They offer multiple poles and very low KV, with the lowest at 390kv. Ideal for swinging those larger props direct drive!

http://www.hobbyking.com/hobbyking/stor ... unner.html

[gingyer]

Re: New brushless outrunners from Hobbyking

Interesting I was wondering about fitting a couple of brushless into the S class

[bigdave]

Re: New brushless outrunners from Hobbyking

Very nice!

[Guest]

Re: New brushless outrunners from Hobbyking

I think brushless is better for higher performance and sporty subs. Unless you fit them with sensors, and use a controller capable of controlling them they won't have the same low speed running abilities as a good quality brushed motor.

Regardless these motors would be the wrong choice for an S-class, too low revving.

[gingyer]

Re: New brushless outrunners from Hobbyking

Thanks sub culture
I was thinking about the 610KV ones that would give
Me roughly 7000rpm

[giovanni]

Re: New brushless outrunners from Hobbyking

These are good motors.
http://www.e-fliterc.com/Products/Defau ... =EFLM4160A

[Guest]

Re: New brushless outrunners from Hobbyking

That's a 3.5hp motor! What sort of 'model' submarines are you building?

[giovanni]

Re: New brushless outrunners from Hobbyking

I'm calculating 1hp with a 14.4 volt battery.
Perhaps I am using the wrong equations.
Continuous amp rating for the motor is 55amps.
The sub that will be using this motor has a 3" prop.

[Guest]

Re: New brushless outrunners from Hobbyking

The motor will produce less power if you run it on lower volts.

But you have a larger motor than is necessary for the application, and are paying a higher price for the motor over a smaller model. I recognise it is generally difficult to find smaller motors in low KV ratings. You can purchase a cheap motor and rewind the armature, or gear down.

It's worth bearing in mind that if a model sub has a fairly efficient hull form and you are not looking to run something like an underwater fast electric, then they rarely need more than 10-20 watts of shaft power (double that figure for electrical power) for small to medium size craft. Bigger craft will need more, but you shouldn't need to exceed 100 watts.

[giovanni]

Re: New brushless outrunners from Hobbyking

I already have the motor. It was for my Hanger 9 large scale Super Cub.
I also have a Castle Hydra ESC 120amp.
I do like the idea of having more power for reversing the sub out of the way of other subs.

[Rogue Sub]

Re: New brushless outrunners from Hobbyking

Power to a pont... After so much your just cavitating and adding no extra work.

[Rogue Sub]

Re: New brushless outrunners from Hobbyking

Any idea how these motors will run on the lower voltage given they are designed for a max of 22v?

[giovanni]

Re: New brushless outrunners from Hobbyking

I will be talking with eFlite tomorrow and will post the info here.

[Guest]

Re: New brushless outrunners from Hobbyking

Any idea how these motors will run on the lower voltage given they are designed for a max of 22v?

They should scale perfectly. Haven't tried those exact motors yet, but have others from HK. Unlike brushed motors, which have the electrical resistance of carbon brushes to affect the RPM at different voltages. That's why brushless motors are shown as RPM per volt, whilst brushed motors tend to specify an RPM at a specific voltage. Having said that, very high quality motors with lower wattages which use precious metal brushes scale very well (low loss in those brushes) and can achieve efficiencies approaching brushless motors. These tend to be makes like Maxon and Portescap, beautiful motors, but only economical if you purchase them surplus- the new prices will make your bank manager sob!

The fact the new brushless motors have a large diameter can and a huge number of poles indicates these will be torque monsters, and should be able to pull anything up to 3" diameter props quite easily.

[giovanni]

Re: New brushless outrunners from Hobbyking

Subculture,
You are right. This eFlite 160 needs a minimum 33 volts.
I will reserve this for my large scale Super Cub airplane.
Here is a better choice for my sub.
http://www.engel-modellbau.eu/catalog/p ... ts_id=2426