Author Topic: Amps  (Read 5203 times)

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Offline Jeremy

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Amps
« on: 27 November 2011, 17:10:22 »
I had originally decided to have 2 speed controllers in my showgirl. The idea was to be able to set it up to tank steer or not as the mood took me. To that end I bought 2 x15amp mtroniks along with one of their power isolators to cut out the BEC on one of them. I now think that it might be best to go for one single speed controller to run both motors. How do I find out how many amps the motors will draw. I presume I need an ammeter? Is there a process that needs to be carried out to find out the max amps that the motors will draw. The motors are MFA 385's which I believe are fairly low drain?. I don't have an ammeter but I'm sure Maplins or similar (Xmas is coming :D) would be able to supply. Any help would be appreciated

Offline colin

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Re: Amps
« Reply #1 on: 28 November 2011, 09:06:05 »
there is of course a couple of ways, one could go about this....

1. is of course the AMP meter, in line between Battery and Motor, then try and stop the motor by clasping the drive axle, with a pair of pliers.... if you can stop the motor, its not very powerfull in the sense of Hose power, take a look at the AMP meter while your trying to stop the motor, and you will see it rise, if you manage to stop the motor, then what is shown on the AMP meter, is the maximum Drain...

2. the other way would be to put a known Ampage battery, directly onto the motors, while the motors are under strain... (boat in the bath or other water), and see how long it takes to drain the batteries... if a 4 Amp battery is empty in 15 Min's, then the motors are drawing about 16 Amps

hope this might help a little

Offline Jeremy

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Re: Amps
« Reply #2 on: 28 November 2011, 19:27:31 »
Thanks for the info. I had a feeling when I asked the question there would not be a single straight answer. Dont you just love our hobby!!!! ???

Offline shipmate60

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Re: Amps
« Reply #3 on: 31 March 2013, 23:07:49 »
Fit a fuse into the supply line and use flat out in the bath.
Start low and if they blow increase the size.
When happy with the fuse add an additional 50% for going astern while the model is traveling ahead.

Bob