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Customer Review
- Reviewed in Canada on June 24, 2021If you just want to spin (little) things around, this motor will work fine. If you want to use these for any serious engineering or robotics applications (or any project that requires a little power), almost any other motor will be better than this one.
Since full specifications were not available in the product description, here are the results from my testing, along with values from other 130-size motors available from reputable suppliers.
Gikfun EK1291 Test Results:
Test Voltage: 5V
No-load current: 350 mA
Stall current: 800 mA
Stall Torque: ~11.2 gf-cm (1.1 N mm)
Assuming the motor produces the advertised 2000 RPM at no load, we can calculate some performance measures:
At maximum efficiency load condition (0.46 N mm) the motor should produce 56 mW of mechanical energy while consuming 2500 mW of electrical energy. The efficiency is a shocking 2.3%! For reference, good brushed DC motors generally have efficiency between 60% and 80%, and small toy motors (in 130-size frames) might range between 20% and 65%. These motors are available for between $2 and $3 CAD in quantity 1 at time of writing, only about twice as expensive for something far more than twice as powerful. I'm not sure quite why these motors are so terrible, although the lower weight than comparables (14 g compared to 16-20 g) may have something to do with it. I do not recommend this product.
Comparison of 130-frame motors peak mechanical power output:
Gikfun 130 3-6V @ 5V (14 g, 1.21 CAD): 58 mW, max efficiency 2.3%
Solarbotics RM2 3-6V @ 3V (20 g, 2.85 CAD): 88.6 mW, max efficiency 22%
Pololu 1117 3-12V @ 6V (18 g, 2.21 CAD): 1325 mW, max efficiency 66%
Pololu 1592 1.5-6V @ 3V (16 g, 2.21 CAD): 2827 mW, max efficiency 56%
The low efficiency comes primarily from the extremely high no-load current combined with the very low stall torque. Do not buy motors without the crucial specifications (voltage, no load speed and current, stall torque and current) because the manufacturer will skimp out on critical components, resulting in a barely functional and grossly inadequate product.
If you just want to spin (little) things around, this motor will work fine. If you want to use these for any serious engineering or robotics applications (or any project that requires a little power), almost any other motor will be better than this one.Low Power, Terrible Efficiency Compared to other 130-size motors
Reviewed in Canada on June 24, 2021
Since full specifications were not available in the product description, here are the results from my testing, along with values from other 130-size motors available from reputable suppliers.
Gikfun EK1291 Test Results:
Test Voltage: 5V
No-load current: 350 mA
Stall current: 800 mA
Stall Torque: ~11.2 gf-cm (1.1 N mm)
Assuming the motor produces the advertised 2000 RPM at no load, we can calculate some performance measures:
At maximum efficiency load condition (0.46 N mm) the motor should produce 56 mW of mechanical energy while consuming 2500 mW of electrical energy. The efficiency is a shocking 2.3%! For reference, good brushed DC motors generally have efficiency between 60% and 80%, and small toy motors (in 130-size frames) might range between 20% and 65%. These motors are available for between $2 and $3 CAD in quantity 1 at time of writing, only about twice as expensive for something far more than twice as powerful. I'm not sure quite why these motors are so terrible, although the lower weight than comparables (14 g compared to 16-20 g) may have something to do with it. I do not recommend this product.
Comparison of 130-frame motors peak mechanical power output:
Gikfun 130 3-6V @ 5V (14 g, 1.21 CAD): 58 mW, max efficiency 2.3%
Solarbotics RM2 3-6V @ 3V (20 g, 2.85 CAD): 88.6 mW, max efficiency 22%
Pololu 1117 3-12V @ 6V (18 g, 2.21 CAD): 1325 mW, max efficiency 66%
Pololu 1592 1.5-6V @ 3V (16 g, 2.21 CAD): 2827 mW, max efficiency 56%
The low efficiency comes primarily from the extremely high no-load current combined with the very low stall torque. Do not buy motors without the crucial specifications (voltage, no load speed and current, stall torque and current) because the manufacturer will skimp out on critical components, resulting in a barely functional and grossly inadequate product.Images in this review
