Building A Sub 250g Carbon Fiber FPV Quadcopter

Most of you know that the FAA has stated that all multirotors that weigh more than 0.55 pounds must be registered in order to prevent fines upwards of $250,000. So there has been an increase in sub 250g Quadcopters and Tricopters. Well today we are gonna talk a little about my FPV Quadcopter and what they look like.

My personal FPV Racing Quadcopter that is under 250 grams!

The frame I chose for this build is an: LHI 210mm Carbon Fiber Frame : Overall I am very pleased with the quality of this frame, very sturdy and lightweight coming in at 70g with all the aluminum hardware. In the future I will be using my Flashforge Creator Pro to 3D print some much lighter spacers to replace the metal spacers that come with the LHI frame.

During this build all of the wiring was done in a minimalistic fashion, I would measure the wire bundles allowing just enough wire to go from A to B then add about an inch to allow for some slack.

How To Tune Your Quadcopter

Well first there are some things you need to check before you try to fly your quad for your first time.

Remember when working with your Quadcopter to always make sure you remove the blades before you do any work.

Number one. You need to make sure all of your wiring is correct. That means checking all your soldering work and crimps to make sure there are no loose connections. Once you have double checked your wiring and are sure you have no loose wires, the next step is to set all of your Gyro Pots to 50%.

Then you will want to power up your quad by plugging in the battery. Once your quad has gone through its startup procedure you can now try to arm you board. When your board is correctly armed a small blue led will turn solid blue indicating that you have successfully armed your KK board. Once your board has been armed you can test the direction of the gyros as well as the rotation of the 4 motors.

The steps to test if your motors are spinning correctly are as follows.
(this procedure may vary between different Flight Control Boards)

1. Make sure you have no props mounted (For Safety)
2. Turn on your transmitter first
3. Plug your battery into your Quadcopter
4. Arm the Flight Control Board
5. Apply only 25% throttle and check the rotation of each motor (see diagram for motor direction)

The steps to test your gyro direction are as follows.

1. Make sure you have no props mounted (For Safety)
2. With the throttle at 25% pick up the Quadcopter and check that the gyros are working correctly
3. If you tilt the aircraft forward the front motors should speed up and if you tilt in reverse the back motors should speed up. (you can use tape or a zip tie mounted on the motor shaft to check direction)

4. If you tilt the aircraft to the left the left motors should speed up
5. If you tilt the aircraft to the right the right motors should speed up