Today’s short post is dedicated to the commutator motor for a 1 to 10 scale radio-controlled car. Let’s see what interesting Chinese manufacturers offer. Let’s install the motor on the AXIAL SCX10 chassis and check it out.

Content
- Introduction
- Specifications
- Packing and scope of delivery
- Appearance
- Installation
- Conclusion
Introduction
Motors for radio-controlled (RC) equipment are mainly used in two types: electric and gasoline. The more common electric ones fall into two broad categories: collector and brushless.
The main difference is that in the collector motor there are brushes, and in the brushless motor the magnet rotates in a magnetic field without friction. And in general, brushed motors are simpler, cheaper, but less durable than brushless motors. Which can also boast of greater speed and power and high efficiency. But these motors need different ESCs.

I have a 550th brushed motor on my DIY RC car. 550 is the size, body length, for reference – in the machine the motor is like in an average screwdriver. The motor, although it is not afraid of water, but without prevention, becomes unusable during the season. The machine is trophy and drives through water and mud.
So another tired budget motor required a replacement, I decided to try Surpass Hobby brand products, their motors are a little more expensive, but they have good reviews and a large selection of characteristics.
Specifications
- Model: SP2171
- Type: collector 550
- Rotor: 5 Slot
- Coils: 12T
- Output shaft diameter: 3.175 mm
- Working voltage: 7.4V
- No load current:<2.1A
- No load speed: 13000±12% rpm
- Current under load: 8.9-49.3A
- Torque: ≥2410.3g*cm
- Diameter: 36mm
- Weight: 215 g.
Packing and scope of delivery
The choice in this lot is not only the standard size (540 or 550), but also the number of turns (13-80) and the number of rotor anchors (3 or 5). The more turns on the motor, the lower the torque and the lower the speed, and the number of anchors affects the smoothness of the start. I took 12T to add speed in a straight line, the torque of my car and so on with a margin.
The motor is delivered in a box with printing and brand name. Inside the box there is a protective soft insert.


Motor made in China.
Contents of delivery:

- Motor 550 12T 5 slot
- 14 AWG 12 cm cables with tamiya connector
- English user manual

Appearance
We proceed to the external inspection of the motor. Dimensions correspond to the declared.
The rotor shaft on both sides is on “industrial” bearings with a protective ring. Output shaft for mounting a 3.17 mm pinion gear with a flat for a set screw. Mounting on a pair of M3 screws – everything is standard here. On the back of the brush preload springs and a place for soldering wires to the regulator.




When installing a gear (21 teeth) on the shaft, a constant problem with the set screws. They are M3 for an internal hexagon, which constantly strives to break. I had to grind a regular m3 screw on a mini grinder.

We check the motor from an adjustable power supply – it rotates smoothly. The aluminum alloy housing does not heat up at idle.

Installation
I have a 1:10 scale AXIAL SCX10 carbon/aluminum clone chassis with a mid-engine layout and a 313mm wheelbase. I don’t worry about torque, the transmission reduction ratio is high.
We solder the leads from the regulator, solder easily – the contacts of the motor are copper-plated. Next, we fasten the motor to the frame, ensuring the gears mesh.

The regulator is the most common, but reliable WP-1060 60A ESC from HobbyWing. The second ESC with a self-made body, to the left of it is responsible for the winch motor. Everything is powered by a 2S (7.4V) battery.

Conclusion

I liked the collector motors from Surpass Hobby, the workmanship is high, the choice of characteristics is large. The car rides with the new motor smoothly without jerks, there is enough torque and speed.
Bought here
More articles on the topic of radio-controlled technology:
- SUVs 1:10
- SUVs on a smaller scale
- Fast boats with BC motors
Thank you for your attention. Enjoy the shopping!