My unplugged ESC blew up and dumped me on my face @ 30KM!

Haha thanks for the compliments, regarding the body armour... Mmm not so much. Longboarding isnt that sensible to begin with and I do it for that awesome free feeling.

Im certainly considering a helmet now but as for armour ill leave that for when im out on my motorbike. A few bumps and scrapes along the way is the going price for that awesome rush you get when carving and bombing at speed :)
 
The mount looks very, very good ! I like the motor counterbearing as well, of which the case also works as a protection for the belt. It is also built very compact.
Ever thinking about making it a commercial product ... ? ?

regards
Sebastien
 
Has there been any parts hunting for a small freewheel that could bolt in somewhere? It is a small space but that would eliminate any motor revs while coasting.
 
All you would need is a freewheel pulley and they exist. If you're okay without brakes it would be a perfect solution. The motor windup when you hit the throttle may be a bad surprise though as it finds the teeth in the freewheel...
 
The motor windup when you hit the throttle may be a bad surprise though as it finds the teeth in the freewheel...
Pick your poison.. Face plant at 20mph or get bucked off when the scoot takes off. LOL

In fact, you'd pretty quickly get the feel for the amount of throttle to take up the slack at low speed and you'll WOT it only once and get that lesson. At high speeds the throttle on won't jerk, at least it would be less than low speed.
 
The motor was using the fet body diodes to dissipate voltage, and there was no load (battery) to clamp it. The ESC booted up, drag kicked in, and you overshot the voltage rating since there was no load to reduce it.

Turn off the drag and just leave it plugged in next time.
 
Wait do you have motors on both front and rear? Was it the motor on the front that locked?

I never use BLDC motors on front wheels unless it has a freewheel. One of the reasons Tesla choice induction motors besides the fact they are cheaper, it that a controller or stator failure does not cause a wheel lock since there are no permanent fields (magnets). There are no elegant solutions around this problem. It happens so quick to is no way to protect against it. The only way to try is to use multiple stators and mutliple controllers per motor such that if only one failed it would not cause the vehicle to lose control. Obviously not practical for our little motors we use on bikes and skateboards and what not. Don't use direct driver hub motors on front wheels people (whether this applies to the original poster or not, just a safety message)! On a skateboard even if the rear locked you still might crash hard, but with the front locking you have no chance at all of biting it hard.

"
Without question any vehicle drivetrain must be safe, and any drivetrain that has individually driven wheels
presents a unique problem in this respect. A key safety goal for Protean’s in-wheel motor design derived
directly from ISO26262 [3] - “no single fault shall prevent the driver from retaining control”. This safety goal,
when applied to an individually electrically driven wheel, essentially boils down to a limit on the wheel
torque error that the electric machine can cause through a single or random fault condition. This safety
goal, along with many others, was defined through following a process defined in ISO26262, which is the
de facto standard for automotive functional safety.

Without question any vehicle drivetrain must be safe, and any drivetrain that has individually driven wheels
presents a unique problem in this respect. A key safety goal for Protean’s in-wheel motor design derived
directly from ISO26262 [3] - “no single fault shall prevent the driver from retaining control”. This safety goal,
when applied to an individually electrically driven wheel, essentially boils down to a limit on the wheel
torque error that the electric machine can cause through a single or random fault condition. This safety
goal, along with many others, was defined through following a process defined in ISO26262, which is the
de facto standard for automotive functional safety."

Too bad we need the torque density of bldc motors to make hub/wheel motors practical. Someone needs to design a super high torque density induction motor. Wouldn't need Chinese neo magnets either so we could make em wherever for cheap
 
So i really wan't to know.
If i leave everything connected and on.
I can go real fast even for a long time and this would never happen right?
has anyone else experienced a similar or close experience?
 
It sounds like leaving the board on and all wires connected is the best choice we have...It hasn't happened to me yet in that fashion, but this thread has made me a little nervous. My only high speed E-board fall to date involved a grey hound that thought I looked tasty, took a bite and it messed me up for a couple of months. :shock: -we really need an emoticon that has squirting blood haha
 
razad7@gmail.com said:
So i really wan't to know.
If i leave everything connected and on.
I can go real fast even for a long time and this would never happen right?
has anyone else experienced a similar or close experience?


you will be fine as long as you dont start the trip on freshly charged batteries and a long downhill. It would overcharge your pack and could also pop caps and/or FETs.
 
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