Which Speed controller?

[Bruce BradshawParticipant @brucebradshaw76954]

Hi,

I’m about to start construction of a Model Slipway Sentinel. This is the second kit i’ve built , but it’s been a while since my last one! I purchased the Motor Kit with her, these are 2 MFA COMO Torpedo 500’s. I want to work out what speed controlers I will need, but can’t find the specification on the MFA website, or remember how you work out the ampage of the speed controler.

 Any Help would be appreciated!

[Len OchiltreeParticipant @lenochiltree67043]

 Hi Bruce,

You could always use their Bobsboards that would keep the cost down,

I tend to use Ripmax Seismic for most of my boats,before that Volcano(no longer made apparently)

Len.

[Bruce BradshawParticipant @brucebradshaw76954]

Thanks Len,

I have used a Viper marine speed controler in the past, but want to make sure that I get the correct ampage, so was wanting to Knowthis/work it out. I did this for the last kit I built as I seem to think there was a formula you use to do this, but can’t remember what it was!!

 Bruce

[TelstarParticipant @telstar]

Hi Bruce

There is no formula as such to work out which ESC, however If you know the voltage you are going to use ( usually not higher than 12 V) this sets one parameter. then the important one is to know what current your motor is going to take. The current is determine largely by the size and type of propellor you are going to use, and also by the type of motor.   Ideally you should measure the actual current your motor/prop choice takes when installed in the model. Knowing the full load current, you then buy a ESC of your choice that is capable of handeling the full load current (plus a bit over) eg motor takes 4A go for a 10A controller. and fit a fuse less than the capacity of the ESC but more than the motor current (in the eg 7 or 8 A) .

There is a school of thought that you should measure the stalled current of your motor, since this is the maximum current that that motor battery combination can take (worst possible conditions with prop fouled).  then buy a ESC capable of carrying that current.

The voltage rating quoted with ESC’s is normally the maximum voltage that will not kill the unit (ie 12V battery working on 12v unit ok. 15v battery on 12v unit -by by unit).

The current rating is also the maximum the unit can handle so fit a fuse lower than this to protect it against accidents. 

Finally if you have 2 motors on one ESC the ESC MUST be at least twice the current handeling of one motor since it will have to handle the current to both motors together

hopr this helps cheers Tom

[Bruce BradshawParticipant @brucebradshaw76954]

Speed control, motors

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