Speed 400 Motor

[Steve Hargreaves - Moderator]

My little boy has a cheap RC boat powered by two RS380 (speed 400) motors.....one has become tempremental so I was going to replace it but which to buy? I know they come in a variety of voltages with 6 & 7.2 Volts being the most common but I don't know which version is currently fitted. Is there a way of telling does any one know?? There are no markings on the case....

 

FYI the boat runs on a 6 cell NiMh battery so 7.2v would seem the obvious choice. My concern is that I run the risk of burning out the controller if I get it wrong......

Edited By Steve Hargreaves on 10/04/2010 15:36:26

[Phil 9]

If it was me I would do an ebay search and buy two cheep matching brushless motors. They would last for ever in a boat.

Edited By Phil B on 10/04/2010 16:12:49

[Tim Mackey]

But then he would need to buy a new ESC as well, and marine versions require reverse etc...

Go for the 7V version

[Steve Hargreaves - Moderator]

Two new ESCs in fact plus a new radio set up.....it is currently controlled by simply switching the motors on & off.......both together send it forward...only one & it turns!!!!

 

Converting it to a full brushless set up would be great fun but not cheap & at the end of the day its just a 6 year old toy!!!

 

I tend to agree with you Timbo...I think the 7V version is the way ahead!!!

[Simon Chaddock]

Steve

Depending on how much you have to pay I would buy two.

With the steering method it is important that they have identical voltage/current characteristics.

[Steve Hargreaves - Moderator]

Totally agree Simon.....I intended to do just that!!!

 

If the replacement has a higher kv or is simply more powerful for whatever reason then its simply going to turn the boat even when running in a straight line.

 

By the way anyone know the best source for these motors?? I keyed "Mabuchi RS380" into Google & it took me to a site in China selling them for $0.65....bit different to the £5 or so we're asked to pay!!!! I doubt they'd want an order for two though!!!

 

I thought they would be pretty easy to source as a "standard" electric flight item but none of the usual suspects seems to stock 'em....just shows how ubiquitous brushless motors have become....

[Frank Skilbeck]

How about here http://www.micronradiocontrol.co.uk/motor_brushed.html

[DENNY]

  Steve,

   Don't you or any of your pals have a pair of motors in their parts box?

   Any thing that is going down to the curb for trash that has a motor in it is torn apart.

   The motor or motors along with any LED's go in my "just in case" box. If you find a pair  

   of motors, mark them so you tell they are a matched set. I sometime find toys with

   good motors in the thrift store that are cheap.

   Denny

[John Privett]

Steve,  as you've just discovered, these things are (or were!) produced in China by the million, at almost zero cost, in multiple variations, with very little clue on the motor as to which version you had. 

 

For a boat you probably want the higher (7.2) voltage motor.  As I recall, for electric flight can motors were pushed rather hard (6v motor run on rather more than 6v!) to get the power required for flight.  This tended to make their life rather short...  My first leccy heli had a brushed 400 motor.  The motor lasted just over an hour,  by which time the brushes were totally "shot."

[Steve Hargreaves - Moderator]

Thanks for the commennts guys......in the end I bought two of these from my LMS....they fitted fine, pull about the same current & have improved the performance of the boat significantly (still not too much for a 6 year old to handle though). I guess they are better quality motors than the typical stuff you get in toys!!!!