Dave_C FPV developed the Rekon 4 FR to create a sub 250g freestyle platform that gests as close as possible to a “classic” five-inch quad. And while performance was the main objective, he still wanted it to be practical for everyday use:
- A robust frame with quick swap arms that can take hard crashes and offers good component protection.
- The option to carry light HD cameras (Naked GoPro, SMO, Insta 360).
- Compatibility with a widely available battery sized (650-850mah 4S).
- And finally, have some margin towards the sub 250g goal, so you do not have to worry about every gram of wire or tape you add to your build (if you are choosing the frame kit instead of the BNF).
Why 4 Inch?
- A 4” platform can be built sub 250g pretty comfortably and you will be able to carry a relatively large battery for 4-6min of aggressive freestyle. The disc load is lower than on a sub 250g 5”, making it less floaty and having more momentum when you “throw” the quad during freestyle tricks.
- A 4” quad can carry a naked GoPro type camera easily and without a noticeable impact on flight performance. The analogue version is still sub 250 with a 25g naked GoPro and a 650mah 4S (unfortunately the digital version is not since the vista adds around 14g)
- 4” t-mount props have gotten pretty mainstream and there is a decent choice and availability (which is not the case for 3.5”)
Motor & prop choice
The motor and propeller configuration was crucial to achieving the desired flight characteristics. After weeks of testing, I finally settled for an intermediate stator size with an aggressive kV. A stator larger than 1804 (e.g. 1606, 2004, 2204) didn’t seem to offer any noticeable improvement of flight characteristics while adding a significant amount of weight. Anything smaller than 1804 just did not have enough torque to make the quad feel locked and snappy enough.
The best performing props were the Gemfan 4023 tribades. They are more on the aggressive side in comparison to the HQ T4x2x3 and while they can be pretty amp hungry on the relatively high kV 1804 motors, they ensure the quad has an impressive punch!
REKON4 FR FREESTYLE FRAME
- Model: 4-inch frame
- Wheelbase: 180mm
- Size: 180*140mm
ZEUS25 V2 AIO 3-6S FLIGHT CONTROLLER
- Input voltage: 3-6S
- FC firmware: BF ZEUSF722_AIO (HGLR)
- Size: 32.5*32.5mm
CADDX POLAR VISTA KIT
- Operating frequency: 5.725-5.850 GHz
- Input power: about 7.4-26.4V
- Channels: 8
REKON 1804 MOTORS
- Motor: KV3500
- Input voltage: 3-4S
- Recommended blade: 4 inches
GEMFAN 4023 4-INCH 3-BLADE PROPELLER
- Quantity: 4 CW & 4 CCW
- 4S: 550mah-1000mAh
1x Rekon FPV Rekon4 FR Sub250g Freestyle Digital Quad
8x Gemfan 4023 4-inch 3-blade propeller
1x Mini hammer antenna (LHCP)
This is a PNP quad, the user must add a receiver to get in the air. If you need one installed, please leave us a message.