The quality of power tools is good or bad, in addition to the online review, review, you can also use other aspects to judge the quality of power tools, such as drill, saw, electric mill, etc.
1) Power cord: look at the material of the wire core, whether it is copper or aluminum, the cross-sectional area of the wire core, and the length of the wire. The outer insulation material, is plastic or rubber, poor quality power line folding resistance is poor, easy to break, short circuit fault, the failure rate is very high. Individual small factories also use copper-covered aluminum wire core power line, copper-covered aluminum is actually copper plated aluminum wire, actually is aluminum wire.
2) Bearing: electric tools are driven by series motor, high speed, long-term friction overload often occurs, poor quality bearing life is short, but the price is cheap, and there is no high load, generally can not be seen, bearing rupture may cause damage to the stator and rotor. Premature bearing wear can cause the stator and rotor to be swept.
3) Rotor commutator: One aspect of rotor life is determined by the quality of the commutator (commonly known as copper head), the quality of the commutator is wear-resistant, long service life, and it is not easy to fly. Poor quality commutator, only a few months will wear to the limit, resulting in rotor scrap or frequent replacement of brushes.
4) Stator coil with enameled wire material: the current market of low-grade power tools, stator is mostly made of copper clad aluminum enameled wire wound, heat resistance is poor, the work of their own heat is also very large, power output is insufficient. The stator with good quality is wound with pure copper enamelled wire, and the high temperature resistant enamelled wire is selected, and the wire diameter matches the motor power.
5) Rotor and stator parameters: the output power of power tools is generally determined by the parameters of the stator and rotor, the material and stack thickness of the silicon steel sheet, the type, specification and number of turns of the enamelled wire used directly affect the performance of power tools. The matching parameters between the rotor and the stator are very important, which can effectively output power for a long time, and it is not easy to heat and lose the output.
6) Brush: the life of the rotor is largely determined by the brush, and the hardness of the brush material directly affects the service life of the rotor commutator, that is, the service life of the rotor. Poor quality brush failure frequently, directly affect the performance of power tools.
7) The material and thickness of the shell: the material and thickness of the shell of the power tool determine the output power and service life of the power tool. Some power tools housing is very thin, easy to damage, some power tools use special materials, both light and strong.
8) The quality of factory assembly: no matter how good the parts are, the assembly quality is not up to standard, which is easy to cause unnecessary failures. If some electric drill stator fixing bolts are not equipped with spring washers, causing the stator to loose, the stator and the rotor cleaning failure, although the fault is small, but affect the use of users.
9) The quality of lithium battery is good or bad, the battery generally uses 18650 batteries, whether to use brand batteries, the battery is not false, and the battery control board has powerful protection function. Some small and medium-sized manufacturers use second-hand batteries, resulting in power tool output is weak, even a few minutes out of power.
