Hi all,
Having recently 'blown up' both my ESC and Motor, I've re-'engined' my tug with an unbranded 500-ish size, brushed motor, geared about 3:1 to the 80mm x ?? four-blade prop, and put in a spare '50Amp' ESC of Taiwanese manufacture.
I thought maybe I should try to get some measurements before going to the pond.
Out of the boat i.e. with no load the motor draws about 1.57 Amps when just starting to turn from 6 Volts or 2.6 A from 12 V.
With the propeller pushing air, on my bench, the current draw is 2.5 A from 6 V at the slowest the radio/ESC will go, ahead or astern.
So today I rigged a 'half-a-test-tank' - my plastic wasn't long enough to get the whole boat in but at the least the stern is submerged to about normal-running depth even though like this she is sitting on the rudder-skeg:
The first sequence of pictures were taken using a freshly-charged 6 V x 3 Ah battery.
At switch-on:
At slow astern - because this jury-rig was a tad unstable, and astern seemed to do OK:
At full astern:
And at full ahead:
Yikes! That seems like a hefty current drain from only a 3 Ah battery. It
might last 15 minutes.
So how about running from 12 Volts? I have an old motorbike battery, rated probably 4 or 5 Ah to try.
This sequence was taken at 12 Volts.
Slow ahead:
At half ahead:
At nearly full ahead:
And at full ahead the meter simply showed Overload - more than twenty Amps. The prop was desperately drawing air, so partially offloading the motor.
At the end of which, the battery cables, and especially the spade-terminal connectors, were extremely hot, whilst the motor and ESC were quite cool.
I guess that 12 Volts might be just a tad too much for my boat! Unless I water-cool the cables ....
I'll be interested to hear what you guys think about these sort of currents?
Geoff