Pygmy

I have a sensored brushless motor but the 3 wires have no A/B/C markings nor descriptive colors.

When I connect them one random way, the motor just shivers and doesn't actually rotate.
Swap 2 wires and presto, it works like a charm.

But - does the fact that it works mean it's connected correctly and the ESC is getting the correct sensor-data ? Or is it possible to wire it up in a way that the motor does seem to work correctly but stuff like ESC Timing doesn't work correctly ?

Mr RCTech

iTrader: (2)

Yes.
The brushless motor uses only one of the three hall sensors.
The second and third are redundant or use as a backup.

You can switch A and C to reverse rotation on the motor.
If the sensor wire is disconnected then the ESC will go into sensorless mode.

Pygmy

Ok, cheers.
But there is a wrong way to connect it, right ?
With my first (random) connection the motor was just shaking when throttle was applied but it wouldn't rotate.

howardcano

iTrader: (37)

If the ESC is for sensored RC motors only, then there is only one way to connect the motor correctly. All other ways will not work.

All of the sensor signals are used by a sensored ESC.

Do NOT attempt to swap any wires to get reverse motor rotation with a sensored ESC.

GerryH

iTrader: (26)

To add to what Howard said, if you have the sensor wire connected, you have to have the wires connected is the correct order. Otherwise, the sensor, detects the rotor is in a specific rotation and fires the magnets that would "pull" the rotor. If the wires are mixed, up it might be firing the magnets that are both forward and backward from the rotation and not go anywhere. This is exactly what you found out.

Here's a good article that explains the basics: http://www.rcuniverse.com/magazine/a...rticle_id=1344

JP4D

Good article, sense we're talking wires here I thought this might be a good conversation to ask one of my own. If you where to take say a 150mm sensor wire and cut it down and resoder it to 100 or 90mm would it interfere with the sensor wires ability or efficiency required for optimal performance?

Roelof

Compleetly wrong information.... All sensors are needed to read the position of the rotor and give a feedback to the ESC so it can adjust the controll to optimise power and power consumption. With a sensored system you can not change wires, there is only one right way to connect.
With a sensorless system you can swap all the wires you want.

BrandonBreh

iTrader: (2)

The wires on a sensor wire are so small it's difficult to solder and very easy to screw up. They are very inexpensive and buying a smaller one and keeping the longer as a backup would be a good idea.

Roelof

It can be done....

JP4D

I've got one one the way that's a more practical for my car, thanks for the forewarning Brandon.

jko

iTrader: (4)

Resurrecting this old thread. Do the motors all have the same a/b/c wires in the same order across brands? Asking to see if there's a way to tell the correct ordering to wire things up. Or is it just trial and error?

gigaplex

iTrader: (2)

Motors have labels indicating which one is which.

Losiracer12

iTrader: (1)

.

GerryH

iTrader: (26)

Every motor I've seen, when looking at the endbell are ABC. The only exception was some Speedpassion motors that had bullet connectors for each phase equally spaced out. And when you think about it, it makes sense. They are always in this order because there is only one rotational direction that's correct for a sensored motor: ABCABC...

ESCs on the other hand can be either ABC or CBA. There also isn't a standard on wire color. Ask me how I found that out

Juglenaut

iTrader: (19)

Most ESC’s have a mode that changes the motors direction..