Testing made possible by generous support from:

Brother Hobby Returner R3 2207 2550kv
 Full Results  [CLICK HERE]

 

A larger stator high Kv edition of the Returner R3 line sent over by Brother Hobby for testing.

Check out the full list of motors in this series here

Summary

Published: Nov 23, 2017 by quadmcfly

Brother Hobby Returner R3 2207 2550kv

Tested KV:2540kv
Weight:30.8g
Stator W:22mm
Stator H:7mm
The BrotherHobby Returner line is a long standing motor line with a deep history in the hobby.  This motor is a variation on the R3 theme, revising the design with an open bottom and upgraded materials to 7075 aluminum, but with other aspects being the same as other R3 series motors. The 3mm internal shaft, bell integrated prop adapter, c-clip shaft retainer, magnets, 3x8x4 bearings, and tolerances are all identical to the earlier motors in the series.  This design keeps the weight low for a 2207, falling just short of 31g. 

Results

This test is quite interesting becuase this motor is essentially identical to an earlier motor, the Multicopter Builders MB2207 2500kv, except for the open bottom design and 7075 upgrades.  The prop list has changed a bit since then, but the comparison is interesting to see.  The open bottom design seems to allow for better cooling of the stators, and there is a noticable reduction in heat losses during the sustained segments of the test. That is probably quite emphasized by static load testing, but is a positive sign.  As a result the numbers are slightly higher on the sustained thrust tests for the new R3.  Other than some small differences, due to the heat disipation, the results are extremely consistent, which is a good indicator of the consistency of the test equipment even with a fairly decent time difference between tests.  Solid results here, even on the heaviest props it barely tapped 40A, staying in the upper 30s and well over 1500g on the heavier 5" props, and around 1450g in the mid 30A range for the mid weight props.  Even late in production as the R3 line is at this point, this motor is still a very good balance of power and current consumption, especially when taking the low weight into account.