T-Motor F40II Review

T-Motor, the leading manufacturer of brushless motors for drones, recently presented their new F40II 2305 motor. It is the successor of the great F40 motor, that I have reviewed few months ago. T-Motor made several changes in the motors design and personally I find it better than the old one. There are two versions of the F40II available:

  • F40II 2305 2400kv
  • F40II 2305 2600kv

According to T-Motor, the new F-Series motor is made of 7075 aluminum alloy. It has a high strength-to-density ratio and is used in the automotive and aviation industry. The motor is slightly lighter than the F40 v1 and weighs 28.9g.

The F40II is a 2305 type motor and has a 14mm long propeller shaft. Diameter of the propeller shaft is 5mm. Here is an overview of the specifications:

  • Dimension: Φ28.4×31mm
  • Stator Diameter: 23mm
  • Stator Length: 5mm
  • Magnet Poles: 14
  • KV: 2400 / 2600kv
  • Weight: 28.9g

propellerdownside

I only ordered one motor for testing and it arrived in a small paper box including mounting screws and a lock nut. Just like the old F40 version there are sets of two motors available.

Manufacturing quality of the F40II motors is superior. Design is slightly changed, which should help for a better heat dissipation. The protection of the mounting holes is gone, maybe for making the motor more light weight. The mounting pattern is standard: M3 16mm x 19mm.

Thrust Tests

I decided to test my F40II 2600kv with the Aikon SEMF 30A BLHeliS ESC, because of its best results in my BLHeliS comparison. I fully charged my 16.000mAh 4S battery, mounted the motor on the RCbenchmark thrust stand and here are the results with three different propellers.

f40ii_2600kv_aikon_4s

As you can notice I pushed the motor only to 80% throttle, while using the 3-bladed-propellers. And yes, it provided amazingly 1410g of thrust! The F40II got very hot, but it is normal for 750W electrical power. Surprisingly the Aikon SEMF 30A didn´t burned even the current was almost 50A 🙂

Summary: The motor runs very smooth, has great quality and provided more than 1.4kg of thrust with a 5″ propeller. I like the design and the light weight of the new F40II and I am going to get some more of these motors for my next FPV build. You can find the 2pcs/set at the official T-Motor webstore and separately here.

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