In this review we are testing the latest EMAX RS2306 2400KV motors (white edition). They come in two variants: 2400kv and 2750kv and we have the former for the test.
Motors are packed in the plastic box filled with foam inserts for protection. Items in each box:
- 1 x RS2306 2400kv motor
- 5 x motor mounting screws for 3mm arms (M3 x 6mm)
- 5 x motor mounting screws for 4mm arms (M3 x 7mm)
- 1 x M5 Aluminium prop locknut
The motor weights 35g, and has bigger 23mm wide stator than the normal 22mm. It has the same famous “red bottom” as previous RS series motors, but comes with a white bell. The white motor bell is a special edition thing, in the future batches it will go back to the normal black color. Prop shaft diameter is 5mm and it is designed for 3S and 4S LiPo batteries.
The larger stator size should in theory give this motor higher the torque and faster response and transition time. But the added weight to the motor might have some negative impact on response due to inertia. Guess we will find out in the testing :)
From thrust data provided by Emax, it shows this motor can draw some crazy high current with heavy 5″ props (as high as 50A on the 2750KV version). I think providing 200A is pretty impractical for today’s LiPo batteries even with burst discharge rate. Therefore this motor should really be paired with lighter 5″ like 5040×3 for example, and use on a lighter weight quad. High RPM, efficient and low in amp draw.
EMAX RS2306 uses shaft screw instead of C-clip, which is a most welcome feature based on the stories with failing c-clips.
RS2306 build quality is excellent, motor feels solid and it was smooth spun by hand.
Performance in the air
I tested RS2306 motors on the following quad:
- QAV-X frame
- FPVModel Quadrant 25A ESC
- Betaflight F3 Flight Controller
- HS1177 Camera
- ImmersionRC Tramp Video Transmitter
- FrSky XM+
- Turnigy Graphene 4S 1500mah
Please refer to static thrust data for the RS2306 motor. This motor seems to have adequate torque of spinning heavy propellers, however be aware of the current draw and efficiency when choosing props. It’s possible to draw 46.4A current running Gemfan 5050×3 props according to the chart.
Flying with HQ 5x4x3 1VS
I instantly noticed how smooth the quad performed. I simply replaced the motors on this build, and I didn’t change PID from previous motors, but it was still flying butter smooth and didn’t notice any jittering. Despite the fact that 5x4x3 props aren’t the most powerful props, I still got a lot of punch with the RS2306. Really nice cornering and responsive feeling in general. I was monitoring amps via OSD and it was never more than 30-35A per motor during punch out.
Flying with DAL Cyclone 5045
EMAX RS2306 motors really shined with the Cyclone T5045 triblade. The quad flew super responsively and locked in. So much punch yet it was really smooth. Maximum amperage was around 42A. Battery was a little warm after the flight, and flight time was around 2.5 mins with a mixture of punch outs and fast cruising.
I am still testing these motors, I will add videos here soon.
The RS2306 is a bit on the heavy side but it is perfectly compensated by the increase in torque and power. It is very snappy, punchy but also very smooth, ideal for racing as well as freestyle flying. Also it was the fastest motor I’ve flown up to date that hasn’t destroyed my batteries!