Model Boat Mayhem
Technical, Techniques, Hints, and Tips => DC Motors (Brushed) and Speed Controllers => Topic started by: thebackways on February 29, 2012, 07:33:42 pm
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i have a large motor in my tug ( 1000mm in length 50mm diameter )
it doesnt have any identification on it and im not sure how many amps it would pull out on the open water ( only tried in the ba...ahem...test tank ;) )
my speed controller is a hitec ' golden brick ( yes i know they suck, but atm is all i have )
as im pricing up speed controllers from action
but the speed controllers all have amp ratings, and as i said im not sure how many amps it pulls, is there anyway to test this without expensive equipement like multimeters and such ?
my speed controller gets awefull hot sailing forwards and backwards in the test tank as the tug is close to 1 meter in length,
im kinda scared of burning out the golden brick if launched on an open lake
will hopefully be running her on a pair of 9.6 volt 3700mah batteries ( but using one at a time )
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but the speed controllers all have amp ratings, and as i said im not sure how many amps it pulls, is there anyway to test this without expensive equipement like multimeters and such ?
You can usually pick up an ammeter for a tenner or so brand new. They're probably cheaper secondhand. You'll need something with a high current rating, though.
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i have a large motor in my tug ( 1000mm in length 50mm diameter )
Now THATS what I call a large motor :} one metre long!
respect lilgoth89
andrew
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Hi ya Lilgoth89
If my memory serves me right I think the brick speed controller is between 15 & 20 amp but the quickest/cheapest way to find out approx amperage of the motor is to stick a 5amp fuse between the motor and the speed controller - stick the model in the bath and put the motor on full bore - if it pops the fuse you know its pulling more than 5 amps. Stick a 10 amp fuse between the motor and speed controller and if it pops that one - do the same with a 15 amp fuse and if it doesnt pop that one, you know the amperage is approx between 10 and 15 amps - that is the quick and rough way to tell how many amps the motor is pulling - a lot cheaper than burning out the speed controller.
aye
john e
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Now THATS what I call a large motor :} one metre long!
respect lilgoth89
andrew
yeah yeah...i was going to put the length of the tug in first...then lost track of where i was due to iceland delivery :)
100mm is the length of the motor,50mm is the diameter O0
tug is 1000mm long and 280mm wide
with the hitec...is it becoming very warm due to the overvolts ? or coz shes pulling so many amps ?
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from memory the golden brick is marked sp6/10 i know they are rated at 10 amps !
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Gold brick is for 7.2-8.4 volts and 10 amps.
Cheers
Nick
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A cheap and cheerful multimeter can be had for under a fiver these days. More than accurate enough for this sort of thing. e.g.
http://www.ebay.co.uk/itm/NEW-DT830B-LCD-Digital-Multimeter-Electric-Voltage-Tester-BATTERY-and-LEADS-/160732680715?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item256c6a120b
A lot of models go up to 10A. If you need more current capability, then just wire in a shunt. http://www.reuk.co.uk/Make-a-Shunt-Resistor.htm
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i just remembered ( looking thru my other thread )
her original ESC was an eletronize fr15hvr running off a 7ah 12v sealed lead acid battery
never saw her on the water in her original condition so i dont know how well she would run on 9.6v
what would the equivilent from action electronics ? (as ive only ever heard good things about this make )