Radio-Controlled Cars: Brushed Motor to Brushless Motor Conversion Guide
Converting Requires Purchase of New Motor and ESC
Motors in electric-powered radio-controlled (RC) cars use one of two types of motors: brushed or brushless. The brushed motors are the original, older style, and the brushless are newer. In order to change over from brushed to brushless, you must first purchase a new brushless motor. It is not possible to convert the motor itself from one type to the other.
In addition, the brushless motors take a different type of electronic speed controller (ESC), so that must also be replaced.
The main advantage of going brushless is—big surprise; wait for it—there are no brushes! Hence, they are maintenance-free. Secondarily, there may be an increase in the speed of the car, but this is not always the case and should not be the main reason for making this change.
Brushed vs. Brushless Visual ComparisonClick thumbnail to view full-size
Tools You'll Need
- Small screwdrivers
- Magnetic parts tray
- Allen wrench
- New brushless motor
- New electronic speed controller
- Small soldering gun or pencil-type soldering iron made for hobbies
Soldering Know-How is Required
- You will need soldering know-how to complete this changeover.
- Use rosin-core solder on electronic parts; this is not only the most effective type for electronics, but it also eliminates the need for the messy application of flux to the piece before soldering.
I learned to solder at a young age; I was about eight years old, and at the time, dad had a heavy, old-fashioned (I'd say antique) soldering iron with about a 1-inch soldering head. It was not for delicate work!
You had to brush flux (a cleaning agent) onto the metal to be soldered beforehand. It did not smell good! But, I learned, and later, when far smaller electric soldering guns came out, it was a breeze to make the transition!
In fact, my dad complimented me on making a better solder joint than someone he'd seen at his job! And that was with the old-fashioned, heavy iron!
But, on to the process!
Solder is molten lead, and it is very hot; it melts at 370 degrees F. (188 degrees C).
(Plain water at 140 degrees F. will cause third-degree burns in just five seconds!)
Be careful when using, and keep flammables away from the work area.
Typical Pencil-Type Soldering Iron
Typical Connections on Brushed MotorsClick thumbnail to view full-size
Removing the Old Motor and ESC
- To change your motor, remove the body from the vehicle, then remove the drive gear cover.
- Disconnect the motor leads from the speed controller.
- Locate the motor mounting screws and unscrew them, setting aside in the parts tray.
- Remove the pinion gear (smaller of the two gears).
- Examine motor lead wires that connect the motor to the ESC and determine whether they are plug-in connectors or soldered connections. If they are plug-in, simply unplug them; if they are soldered connections, you'll need to unsolder them before proceeding.
Brushed vs. Brushless ESC Visual ComparisonClick thumbnail to view full-size
Installing the New ESC and Motor
Attach the new ESC lead wires to the new motor. ESCs for brushless motors have five wires to connect: three attach to the motor, and two go to the battery pack. The wires for the motor are labeled “A,” “B,” and “C.” The wires for the battery are labeled "positive" and "negative" (+ and -). The wires are also color-coded to the attachment points.
When installing the new motor and ESC in the vehicle, be careful in routing the wires to avoid any contact of the insulation against moving parts, which could cause breakdown of the insulation and a short.
Although your old motor may have had plug-in connectors, all brushless motors require soldered connections. Be sure the connectors are free of dirt or any type of oily residue prior to soldering. For any heavy deposits, clean with a piece of fine sandpaper or emery cloth. Rubbing alcohol works well for minor grime, and also to finish off after a sanding treatment.
Check to be sure you have attached the wires securely to the new motor and install it into the car. Re-install the pinion gear and drive gear cover. You are halfway done!
Removing Old and Installing New ESC
- Locate the speed controller and unplug the battery connectors. Then, remove it from the vehicle. Sometimes they are screwed in with mounting screws; sometimes they are held in with double-sided foam tape.
- Fit the new ESC into the vehicle. It may be necessary to move it to a different spot than was occupied by the original one, depending on size and configuration.
- Decide whether you wish to use double-sided foam tape or mounting screws, if that option is available, on the new speed controller. Mount the new ESC in the chosen location; hook up the two power leads to a fully charged battery pack, and the third wire to the receiver. Bench test the operation.
Brushless Motor and ESC
Brushless Motor Installed
Finished With Install—Now Test!
Double-check all your connections, and turn on the car, then your transmitter.
If the car or truck will not operate or works erratically after you have made the changeover, double-check all your connections for tight fit and proper polarity.
Be sure your transmitter batteries are fully charged, as well.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2010 Liz Elias