Please help guys, I'm just starting making my own rc car but i bought brushless motor with 40a ESC but the problem is i didn't know that it has no reverse function. I just discovered it lately. after searching many possible solution i found this forum and i find out I can use Relay but its "dangerous" because It will destroy the ESC, Then i saw someone use a 6pin switch to change the directional of the BLDC motor then my question is is it safe to do that way? Please help guys, I just don't have extra money to buy new ESC with reversing function.
Welcome to the forum
To reverse the direction of a BLDC motor you just need to swap two of the wires connected to it.
You could do this with a relay but would need to be careful not to do it while the motor was running. Using a switch is presumably not a satisfactory solution for an RC car
Thankyou for reply. I watched someone use a 6pin switch then he use servo to control the switch. is there a problem with that? am I gonna destroy my esc with that method?
It sounds like the switch was being used to swap the two connections, which is exactly what a relay would do
I know of no reason why swapping the two wires would cause a problem when the motor was swapped whatever the method used, but I cannot be sure
Can you post a link to where you saw that using a relay could damage the ESC
Here Brother.
I note that I participated in that topic and said much the same thing as I said here, so I don't know whether it is safe
alright, thankyou @UKHeliBob
gonna look for some advice. hope there is a safe solution without buying new ESC with reverse function.
One way to find out...
When the motor is not running, I don't see any obvious reason why it would be dangerous.
When the motor is running - especially at speed - it's of course quite obviously dangerous to do so, for both the motor and the ESC, though I can't predict whether there will be damage and if so which of the two is to die first. Back EMF is a force to be reckoned with.
A BLDC might have three, eight or nine wires.
- Three fat wires would be just the phases (blue, green, yellow)
- Eight wires would add feedback (three skinny wires, B/G/Y) with power and ground for the Hall sensors on skinny B/G/Y.
- Nine wires would have a temperature sensor (white wire)
= two "phase" wires
I'm thinking about using a 6pin switch, they said that if you use relay there will be possible you destroy your ESC when you switch direction while the motor running, But if I use 6pin switch to change the direction of my BLDC motor it will be safe i think, because before I'm gonna switch to reverse the motor is already stopped. what do you think?
Guys is this safe method? Help...
Are you sure? SomeESCs can be flashed with updated or even different firmware.
What exact ESC do you have? Make and model.
No.
a7
It is just exchanging 2 of the phase wires. Opinions here seem to be that is not safe whilst the ESC is powered and outputting signals
@helphelpme nice picture.
Do you have a make and model number? That could be anything. I'm not going to search pictures to see if it turns up.
Is there any other printing on it?
Do you have a link to where you purchased this item?
a7
i bought it here
OK!
It says
BLheli ESC
This means it runs the popular BLHeli ESC firmware.
You can configure it for backwards, if the version it runs is young enough.
Use the BLHeli configurator.
If it is running some old version of the firmware, you can flash an update, again one would use the BLHeli configurator to accomplish that.
It's not hard, just a bit pesky.
The result should be a motor that spins clockwise for values above half throttle, increasingly faster, and anticlockwise for values below half throttle, increasingly faster.
a7
okay i'll try that. thankyou for info.
Your other topic on the same subject has been locked and your other account has been suspended
Why did you create a second account and a duplicate topic ?
Think yourself lucky that this account has not also been suspended
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There is NO difference between a relay and a six-pin switch, from an electrical perspective.
Also, mind: motor stopped means no movement AND no power supply. An unpowered motor that is freely running can still produce significant voltages (it becomes a generator) so reversing polarity may cause problems in the driver, while a powered motor that is not moving (stuck, stalled) does have a lot of energy stored in magnetic fields.
The safest, easiest way to get what you want is an ESC that is designed for this.
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