$500 worth of fail
Brandon,
Too much fail to list
Awww… crap. Sorry to see that, but pushing into new frontiers does bring risk.
And actually, as long as you and others gained knowledge from the process and the path, it is not really a fail - I often learn far more from mishaps and things not working perfectly. Regardless of this setback, I still wish I was in the digital manufacture class right now and hope to see it come around again.
Seeing those pallet jacks move was still cool!
JAG “Burned Motor Control Envy” MAN
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Better to have failed and lost than to have never failed at all. Er, or something like that.
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It was spectacular… BIG arcs…
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@Brandon_Green so did you or @artg_dms figure out what caused the initial failure? Was this the first time we tried all four battery packs?
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Gotta love the makespace. No real failures just a pathway that has been eliminated! Onward!
Lance can get you the monster spool magnet wire if you want to rewind the stator. 
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It was the first time we had all 4 packs(25c x 4ah x 4 = 400 amps max recommended discharge), had only 2 packs on pallet kart test. The current idea is that we dumped too much current into the motor, which fried the motor (burned insulation off wire in windings), which then shorted and took the speed controller with it. The motor and controller are designed for RC airplanes, so the continuous heavy load is not at all what they were designed for.
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Did it catch on fire?
The actual plywood didn’t catch fire, the circuit board inside the speed controllers vaporized in spots, the fireworks stopped quickly after pulling the battery disconnect. Any guesses on how much current would need to go through a 10 awg wire to get a connection to the board hot enough to desolder itself?
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So is there a plan B? Do we buy a new motor and speed controller?
In short, yes, ordered 8hp brushed motor.
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I can mathtimate it. Copper wire at 10 AWG is about 1 milliohm per foot. Say we need to dissipate about 40W of heat in one inch of wire to melt the solder. P = I^2*R, sqrt(P/R) = I.
sqrt(40W/0.000083 ohms) = ~692 amps.
I’d believe it.
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We probably would have had better luck attaching the motor to a propeller and using it to move the kart.
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Some friends did an electric car build years ago, and they were asking me to help them design a motor controller for it. I didn’t have enough experience at the time to even approach it, but we all learned a few things.
Among them: be really careful with brushed motors and coasting/downhill conditions. Once you turn that motor into a generator, without a field coil you have no way to modulate the amount of energy coming back out of the motor!
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No, the real question is,
Did it Halt and Catch Fire?
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