Q: May I have a motor with 12V/5000RPM/25mm, fan/car motor or could you tell me what information I should provide to get the motor I want?
A: Normally we recommend the motors based on the size constraints like diameter, length, width, the shaft diameter, rated voltage, no load speed and stall torque or on load speed and on load torque, lifetime requirements and noise level etc. And different motors might be needed for the same application if with different design. If you can send us a picture of your sample with size information, your existing spec or the detailed requirements we mentioned above, we'll see what we can do. The more information you provide; the better for us to provide what you exactly need.
Q: What kind brushes do you use in the motor?
A: There are two kind brushes we normally use: the metal brush and carbon brush. We choose based on the speed, current and lifetime requirements. For quite small motors, we only have metal brushes while for big ones we only have carbon brushes. Compared with metal brushes, the lifetime of carbon brushes are longer since it will reduce the wear on the commutator. But for low speed motor, the carbon dust might not be able to burn in time which will cause failure too.