econfly
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DJI 1552 Folding Propeller
DJI introduced the 1552 folding propeller a few months after the release of its S800 Evo multirotor, claiming, “with a new advanced airfoil design and stronger materials, it gives a 10% efficiency boost when used with an S800 EVO.” In the following months the new prop became standard on the Evo and on DJI’s recently released S1000.
Here we examine the 1552’s performance in detail, and compare it to the original Evo folding prop, as well as to the T-Motor one-piece 15-inch propeller (the T-Motor prop can mount directly to the 4114 motor using supplied hardware and leaving the folding mount points open).
Summary
In sum, the 1552 prop delivers on DJI’s claim of a 10% efficiency gain, yet does not reach the level of performance that T-Motor’s one-piece prop provides. Compared to the original Evo prop, the 1552 offers more thrust at every throttle position, and, more importantly, power consumption for any given level of thrust is lower. Where it matters, at about 1.25 to 1.50 kg of thrust per motor, the new prop demands 9% less power than the original Evo prop – just under the 10% improvement DJI claims.
Vibration is not measurably different, and remains significantly greater than that experienced with the T-Motor prop. However, vibration is managed by the entire flight and camera system, and none of these props has produced a noticeable vibration problem in my actual Evo flights with a paired Zenmuse Z-15.
Initial Impressions and Tests
The 1552 differs significantly in shape from the original Evo prop, is less carbon-fiber-looking in appearance, and more flexible. The mount to DJI’s 4114 motor changes slightly, with a thicker top bracket and no internal mount screws directly to the motor. The propeller mount screws are slightly longer than those of the original Evo props, and an upgrade from the Evo originals therefore requires new props as well as new brackets and screws.
For six pairs of the 1552 blades, weight varied from 6.45 to 6.60 grams per blade. This is much improved over the 5.00 to 5.51 gram range I found for six pairs of original Evo folding props, and comparable in percentage terms to the 22.48 to 24.65 grams weight range found in six T-Motor props. The 1552s were delivered in well-matched pairs, as were the original props on my S800 Evo. If mixed, it would be prudent to re-match pairs using an accurate scale (I am using an RCBS digital scale). T-Motor props, while varying in weight as noted, were all balanced from the factory.
For testing, I mounted a DJI 4114 motor to a thrust meter and controlled it with a T-Motor 40 amp ESC. Power is delivered by an eFuel power supply set at 6S voltage. An Eagle Tree data logger feeds real-time power data to a computer. The thrust meter’s cover is removed in the accompanying photo (more on that later). Prior to testing I checked the meter for calibration using known weights as well as a spring scale. ESC throttle calibration was checked prior to each test.
At every throttle position the 1552 props provide more thrust than the Evo originals, though generally still not as much as the T-Motor prop. For given throttle positions, thrust for the new props measures as much as 20% more than that delivered by the original Evo props, with peak improvement at about 65% throttle.
Efficiency
The improved thrust provided by the 1552 props is combined with very nice efficiency gains. Power consumption, measured in watts, is lower for the 1552 props when compared to the original Evo props for all but extreme thrust levels. Efficiency peaks at just under a 10% improvement over the original Evo props, but this improvement is delivered where it matters – right at the thrust levels required to hover an S800 Evo loaded with battery and Zenmuse.
The T-Motor props dominate, and are as much as six to seven percent more efficient than the 1552s.
Vibrations
Vibration measurement is tricky business, and no one approach can capture the myriad issues (or mitigations) in an entire airframe and mounted camera system. Nonetheless, objective vibration measurement is something sorely lacking in the multirotor world, and any objective data can only inform the situation a bit more.
To measure vibration I mounted an Extech VB300 to the horizontal bar carrying thrust from the hard-mounted motor to the thrust meter’s strain gauge. The VB300 measures acceleration in 3 axes every 50 milliseconds, and I captured those accelerations for each prop with throttle set to deliver 1.25 kg of thrust.
Every triplet of acceleration data (X,Y,Z values, with Z adjusted to remove gravity) is combined to get a root mean square value. Results are as follows. Clearly the T-Motor prop is winning the vibration contest, and while the original Evo props appear to vary more than the new 1552s, the mean and standard deviation for the series are immaterially different. There simply is no apparent difference – good or bad – between vibrations for the 1552 props and the original Evo folders as measured here.
Final Thoughts
DJI’s 1552 folding props work as advertised and are a solid improvement over the Evo’s original folding props. They provide about 10% longer flight times without any measurable downside. T-Motor’s one-piece carbon fiber prop is better, but costs substantially more, and does not offer the convenience in transport that a folding prop can provide. Those flying the S800 Evo with original props would do well to upgrade to the 1552s, while Evo and S1000 flyers may want to consider the T-Motor option if the benefit of a folding prop is worth trading for even greater performance.
DJI introduced the 1552 folding propeller a few months after the release of its S800 Evo multirotor, claiming, “with a new advanced airfoil design and stronger materials, it gives a 10% efficiency boost when used with an S800 EVO.” In the following months the new prop became standard on the Evo and on DJI’s recently released S1000.
Here we examine the 1552’s performance in detail, and compare it to the original Evo folding prop, as well as to the T-Motor one-piece 15-inch propeller (the T-Motor prop can mount directly to the 4114 motor using supplied hardware and leaving the folding mount points open).
Summary
In sum, the 1552 prop delivers on DJI’s claim of a 10% efficiency gain, yet does not reach the level of performance that T-Motor’s one-piece prop provides. Compared to the original Evo prop, the 1552 offers more thrust at every throttle position, and, more importantly, power consumption for any given level of thrust is lower. Where it matters, at about 1.25 to 1.50 kg of thrust per motor, the new prop demands 9% less power than the original Evo prop – just under the 10% improvement DJI claims.
Vibration is not measurably different, and remains significantly greater than that experienced with the T-Motor prop. However, vibration is managed by the entire flight and camera system, and none of these props has produced a noticeable vibration problem in my actual Evo flights with a paired Zenmuse Z-15.
Initial Impressions and Tests
The 1552 differs significantly in shape from the original Evo prop, is less carbon-fiber-looking in appearance, and more flexible. The mount to DJI’s 4114 motor changes slightly, with a thicker top bracket and no internal mount screws directly to the motor. The propeller mount screws are slightly longer than those of the original Evo props, and an upgrade from the Evo originals therefore requires new props as well as new brackets and screws.
For six pairs of the 1552 blades, weight varied from 6.45 to 6.60 grams per blade. This is much improved over the 5.00 to 5.51 gram range I found for six pairs of original Evo folding props, and comparable in percentage terms to the 22.48 to 24.65 grams weight range found in six T-Motor props. The 1552s were delivered in well-matched pairs, as were the original props on my S800 Evo. If mixed, it would be prudent to re-match pairs using an accurate scale (I am using an RCBS digital scale). T-Motor props, while varying in weight as noted, were all balanced from the factory.
For testing, I mounted a DJI 4114 motor to a thrust meter and controlled it with a T-Motor 40 amp ESC. Power is delivered by an eFuel power supply set at 6S voltage. An Eagle Tree data logger feeds real-time power data to a computer. The thrust meter’s cover is removed in the accompanying photo (more on that later). Prior to testing I checked the meter for calibration using known weights as well as a spring scale. ESC throttle calibration was checked prior to each test.
At every throttle position the 1552 props provide more thrust than the Evo originals, though generally still not as much as the T-Motor prop. For given throttle positions, thrust for the new props measures as much as 20% more than that delivered by the original Evo props, with peak improvement at about 65% throttle.
Efficiency
The improved thrust provided by the 1552 props is combined with very nice efficiency gains. Power consumption, measured in watts, is lower for the 1552 props when compared to the original Evo props for all but extreme thrust levels. Efficiency peaks at just under a 10% improvement over the original Evo props, but this improvement is delivered where it matters – right at the thrust levels required to hover an S800 Evo loaded with battery and Zenmuse.
The T-Motor props dominate, and are as much as six to seven percent more efficient than the 1552s.
Vibrations
Vibration measurement is tricky business, and no one approach can capture the myriad issues (or mitigations) in an entire airframe and mounted camera system. Nonetheless, objective vibration measurement is something sorely lacking in the multirotor world, and any objective data can only inform the situation a bit more.
To measure vibration I mounted an Extech VB300 to the horizontal bar carrying thrust from the hard-mounted motor to the thrust meter’s strain gauge. The VB300 measures acceleration in 3 axes every 50 milliseconds, and I captured those accelerations for each prop with throttle set to deliver 1.25 kg of thrust.
Every triplet of acceleration data (X,Y,Z values, with Z adjusted to remove gravity) is combined to get a root mean square value. Results are as follows. Clearly the T-Motor prop is winning the vibration contest, and while the original Evo props appear to vary more than the new 1552s, the mean and standard deviation for the series are immaterially different. There simply is no apparent difference – good or bad – between vibrations for the 1552 props and the original Evo folders as measured here.
Final Thoughts
DJI’s 1552 folding props work as advertised and are a solid improvement over the Evo’s original folding props. They provide about 10% longer flight times without any measurable downside. T-Motor’s one-piece carbon fiber prop is better, but costs substantially more, and does not offer the convenience in transport that a folding prop can provide. Those flying the S800 Evo with original props would do well to upgrade to the 1552s, while Evo and S1000 flyers may want to consider the T-Motor option if the benefit of a folding prop is worth trading for even greater performance.
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