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ZMX v2 2205 2800kv Full Results  [CLICK HERE]

  

This is the updated 2205 high KV motor from ZMX. Thanks to SIlver-Drone for sending it over for testing.

I've had a lot of ZMX motors come across my bench and I've always been impressed.  The motors are built well, and machined well, tolerances are extremely tight.  This 2800kv is no exception.  These are just well engineered motors.  This v2 is a significant upgrade from the v1 with a new bell design that allows for better cooling and most importantly new magnets.  This is very similar to the v2 2300kv that has already been tested, using the same curved N52SH (the only confirmed super high temp magnets of any motor I've tested) magnets and NSK bearings.  It is worth metioning that while the test version I was sent has a black bell top, the shipping version has a purple top. It is also worth mentioning that the latest version of this motor has been upgraded to 7075 aluminum and thicker magnets.  We'll talk more about that below.  The real win here for the 2205 v2 motors is the weight.  At only 26 grams they pack a powerful punch for the weight cost, and given how tough the 6063 version of these motors have proven to be, the 7075 version should be virtually indestructible.

Results

There's some really interesting things going on in the numbers with this motor.  It is really pushing the limits of the KV for this stator size and it shows up here in the results.  This motor nails it on the 4" props, but at the cost of a raise of a couple amps in current at the top end at WOT. Interestingly enough by the time it drops to 75% though it has essentially gained that efficiency back, Most of the loss seems to happen in the top 5% of the throttle.  A really interesting byproduct of the newer N52 based designs is that at similar thrust they are a lot more linear in efficiency than the older generation N38SH and N45SH designs.  The stronger the magnet the less RPM and efficiency loss due to KV raise is present in the motor.  That's been pretty clearly demonstrated across a large sample of motors tested, and it is particularly evident here.  At 75% throttle on the 5x4x3, this motor is hitting 925g of thrust at just over 20A.  The throttle ramp on the ZMXv2 2300kv motor is showing 925g at over 19A, so only a 1A difference at equivalent thrust.  Unloaded in the air that difference will be negligable due to the difference of torque loading.  In terms of RPM delta though the lower KV motor still wins, but by how much is the subject of further study.  A final intersting point here is the 5x4x3 prop.  The numbers droped off so sharply on the 5x4x3 compared to the 5x4.5HBN that I reran the test 3 times to make sure it was accurate.  It seems that the thinner magnest combined with the high KV and heavy props are simply hitting a wall here with the 5x4x3 under static load.  The amp draw on the top end of this prop spiked up to over 35A and the thrust was less than a number of the other lower KV motors that have been tested.  The prop will probably unload a good deal in the air, but even with unloading, 5x4x3 is probably pushing the limits with this motor.