This frame is designed for a toothpick style hexacopter.

If you want to mount additional ESCs under the frame, the Minimal Bottom Plate 1.5mm is reccomended for protecting them.

• FC and ESC mounting holes: 25.5x25.5mm, 20x20mm, 16x16mm, M2
• Motor mounting holes:  9x9mm -12x12mm, M2
• Weight: About 9.5g
• Betaflight Motors Mixer: HEX X

The recommended prop size is 3". As for 3.5", it is possible but a little bit tight for mounting a battery.

Using a not-too-simplified AIO flight controller which has enough soldering pads such as two sets of UARTs and a LED strip, it is not difficult to build a hexacopter by adding a 4-in-1 ESC or two individual ESCs. The following picture shows an example of a 3" build using a JHEMCU GHF13AIO FC F411 2-4S 13A with a 16x16mm 4-in-1 ESC by Flywoo.

GHF13AIO has soldering pads for LED_STRIP and I2C, I used the LED_STRIP (A08) pad for Motor 5 and the SCL (B08) pad for Motor 6. The corresponding CLI diff are as follows:

# resources
resource MOTOR 5 A08
resource MOTOR 6 B08
resource LED_STRIP 1 NONE
resource I2C_SCL 1 NONE

# timer
timer B08 AF2

# dma
dma pin B08 0
# pin B08: DMA1 Stream 7 Channel 2