For those looking at propeller upgrades, it's good to know the stock propeller dimensions and pitch and how they compare to upgrades like the MAS.
Here are are some averages of stock propellers that I measured:
(Numbers have been rounded for ease of math)
255 mm long (10.0 in)
26.5 mm wide (at 75% from hub) (1.0 in)
27.5 mm wide at widest point
6 mm blade height (at 75% from hub) (0.24 in)
pitch = 2.36 diameter height/width
pitch = 2.36 * 10 * .24 / 1 = 5.664"
OR
pitch = 2.36 * 255 * 6 / 26.5 = 136.25 mm or 5.4"
So it appears that the stock GoPro Karma Propellers are somewhere around a 10 x 5.5 prop.
The MAS upgrades are a 10 x 4.5 prop.
Decreasing the pitch by a full inch should decrease the power usage at any given RPM by about 14% giving you longer batter life as well as being a quieter blade.
Performance at any given RPM would be lost which could be corrected by increasing the RPM and thereby negating some of the efficiency gain. However, since these drones are used in mostly "static" flight modes as a stable camera platform, you should have an overall longer battery life.
power = k rpm^3 diameter^4 pitch
For power in Watts, and diameter and pitch in inches, k is about 5.3×10-15 for an average model airplane propeller.
k = 5.3x10-15 = 0.0000000000000053
Stock Blade at 10000 RPM
power = 0.0000000000000053 * 10000^3 * 10^4 * 5.5 = 291.5 watts
MAS Blade at 10000 RPM
power = 0.0000000000000053 * 10000^3 * 10^4 * 4.5 = 238.5 watts
238.5/291.5 = ~ 18%
When using the Static Thrust Calculator, chose the propeller type of APC.
Cheers!
Brett
References
Here are are some averages of stock propellers that I measured:
(Numbers have been rounded for ease of math)
255 mm long (10.0 in)
26.5 mm wide (at 75% from hub) (1.0 in)
27.5 mm wide at widest point
6 mm blade height (at 75% from hub) (0.24 in)
pitch = 2.36 diameter height/width
pitch = 2.36 * 10 * .24 / 1 = 5.664"
OR
pitch = 2.36 * 255 * 6 / 26.5 = 136.25 mm or 5.4"
So it appears that the stock GoPro Karma Propellers are somewhere around a 10 x 5.5 prop.
The MAS upgrades are a 10 x 4.5 prop.
Decreasing the pitch by a full inch should decrease the power usage at any given RPM by about 14% giving you longer batter life as well as being a quieter blade.
Performance at any given RPM would be lost which could be corrected by increasing the RPM and thereby negating some of the efficiency gain. However, since these drones are used in mostly "static" flight modes as a stable camera platform, you should have an overall longer battery life.
power = k rpm^3 diameter^4 pitch
For power in Watts, and diameter and pitch in inches, k is about 5.3×10-15 for an average model airplane propeller.
k = 5.3x10-15 = 0.0000000000000053
Stock Blade at 10000 RPM
power = 0.0000000000000053 * 10000^3 * 10^4 * 5.5 = 291.5 watts
MAS Blade at 10000 RPM
power = 0.0000000000000053 * 10000^3 * 10^4 * 4.5 = 238.5 watts
238.5/291.5 = ~ 18%
When using the Static Thrust Calculator, chose the propeller type of APC.
Cheers!
Brett
References

Propeller Basics
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