ESC issues

[kunas]

i just put together another scaler using scx 10 running gear, everything turns free as should be with integy 35t motor connected, i put a ae2 esc on it finished the wiring and now when trying to turn the running gear over by hand WITHOUT a battery hooked up its almost impossible, its turns hard enough to where it seems like it should break something. unhook 1 of the motor wires coming from the esc and it turns as well as any other scaler i have does. im grabbing a wheel and trying to rotate it there, i cant understand how the esc is doing that without a battery hooked up, i could understand it if under power due to drag brake ect but without power im clueless im putting a HHbrxl in it now but i would still like to understand whats going on, i pulled the ae2 esc out of another known working scaler that i robbed parts from thanks Ron

[braq]

Originally Posted by kunas

i just put together another scaler using scx 10 running gear, everything turns free as should be with integy 35t motor connected, i put a ae2 esc on it finished the wiring and now when trying to turn the running gear over by hand WITHOUT a battery hooked up its almost impossible, its turns hard enough to where it seems like it should break something. unhook 1 of the motor wires coming from the esc and it turns as well as any other scaler i have does. im grabbing a wheel and trying to rotate it there, i cant understand how the esc is doing that without a battery hooked up, i could understand it if under power due to drag brake ect but without power im clueless im putting a HHbrxl in it now but i would still like to understand whats going on, i pulled the ae2 esc out of another known working scaler that i robbed parts from thanks Ron

Hi

Short your two motor wires and check if it is the same as with the ESC (no ESC or battery, just connect both motor wires together).

cheers

braq

[SuperRoo]

The drag brake is working. Disconnecting the motor wire from the ESC is disconnecting the drag brake.

Yes it works even when turned off and battery disconnected.

[CiLyX]

So you're saying it feels like the motor is under load while its plugged in but no battery is connected?

[kunas]

Originally Posted by CiLyX

So you're saying it feels like the motor is under load while its plugged in but no battery is connected?

yes

[kunas]

Originally Posted by braq

Hi

Short your two motor wires and check if it is the same as with the ESC (no ESC or battery, just connect both motor wires together).

cheers

braq

unhooked the esc from the motor and touched the 2 motor wires together and the motor is locking up so its a motor issue thanks Ron

[braq]

Originally Posted by kunas

unhooked the esc from the motor and touched the 2 motor wires together and the motor is locking up so its a motor issue thanks Ron

When you spin the motor (through wheels & gearbox) it works like a generator. Motor wires not connected to anything, you feel some resistance, if you short them (or as pointed out the drag brake on the ESC will just do that) you now work against this load/short (generating eventually heat, but that takes a little while).

So your system is probably just fine (if you have a 2nd motor you can try that with shortened motor wires and will probably come to the same conclusion), this might actually be your first system with a drag brake (that shorts the motor leads even without being energized itself).

cheers

braq

[JohnRobHolmes]

There is no issue. This is normal operation of an ESC when it is switched off. The FETs allow reverse current naturally (body diode is integrated) and are arranged in an H bridge, so when you turn your motor there is always a shorted path and "drag" brake is active. Sometimes it won't do this if a FET gate is holding some charge, still no worries.

[kunas]

Originally Posted by braq

When you spin the motor (through wheels & gearbox) it works like a generator. Motor wires not connected to anything, you feel some resistance, if you short them (or as pointed out the drag brake on the ESC will just do that) you now work against this load/short (generating eventually heat, but that takes a little while).

So your system is probably just fine (if you have a 2nd motor you can try that with shortened motor wires and will probably come to the same conclusion), this might actually be your first system with a drag brake (that shorts the motor leads even without being energized itself).

cheers

braq

i have MMPs, BRXLs,FXRs i dont ever remember them doing this, i guess ill leave it alone if you all feel its normal thanks Ron

[JohnRobHolmes]

It doesnt always happen, depends on how the controller shuts down.