After breaking an arm for the second time, I transferred the guts from Wr0ngSparrow into the Diatone GT-M3 frame so that I could have replaceable arms for the future. Frame worked well, so building a second one so I don't have to switch to a 5" half way through a race day (what an adjustment!!)

Build notes:

• The frame is a pretty tight build, had to experiment a bunch with different screws and spacers. The cornucopia of screws that come the frame are all phillips head, and I prefer hex, so used my own screws, mostly 8mm, then some longer ones (2x12mm, 2x16mm) for the stack.
• The esc I used has the vbat pads in an awkward place. I prefer the wires going out the back, so had to reposition them for this build, as well as flatten them a bit to make space in the stack
• The mmcx antenna attachment is a bit bulky for such a tight build, but I was able to position it to either the front or back of the stack ok. i think I prefer it in the back. The Rx backpack makes it hard to read the LCD display though, you may be able to flip the vtx upside down to make it easier to read.
• You can probably put the Rx to the front of the stack if you dont want a backpack, but might need longer antenna wires to reach the tubes
• I could not get softserial to work on any of the rx/tx pads near the sbus pad on the cl racing mini, but was able to get it to work on the led_strip pad.
• Camera control pad works well for controlling the micro sparrow 2. Hold pitch up to get to the OSD config menu, and hold roll right to switch between camera profiles. Yaw right for the standard picture settings menu.
• The camera fits and is well protected withing the aluminum guards
• Make sure you aren't pinching any wires in the back when you bring down the aluminum guard to close things up. It doesn't close completely clean, may have to move the backpack around to get it to close. There is some resistance from tpu bits when closing, but it does stay/screw closed with some pressure.
  NaNundefinedWire clips on the arms are https://www.thingiverse.com/thing:2901604
  NaNundefinedAntenna holder is: https://www.thingiverse.com/thing:2901614
  NaNundefinedRx backpack is: https://www.thingiverse.com/thing:2901623

Relevant betaflight config:

# Matches the wiring I did (esc motorN -> clracing MotorN) , didn't feel like ordering by wire swap
resource MOTOR 1 B01
resource MOTOR 2 A02
resource MOTOR 3 B00
resource MOTOR 4 A03

# Sets up softserial for telemetry on the led_strip pad
resource MOTOR 5 NONE
resource LED_STRIP 1 NONE
resource SERIAL_TX 11 B08
feature SOFTSERIAL
feature TELEMETRY

# Rx on Serial1, SmartAudio on Serial4, Telem on softserial 11
serial 0 64 115200 57600 0 115200
serial 3 2048 115200 57600 0 115200
serial 30 32 115200 57600 0 115200

# R-XSR is SBUS
set serialrx_provider = SBUS

# Board orientation as built
set align_board_yaw = 180

You'll also need to reverse two motors in blheli32suite, which two depends on if you fly reversed motors.

Maiden flight:

Update 6/5/18: Burned out the esc, so replaced with a ori32. Its a tight fit - had to put the lipo pads towards the front, facing up, and run the lipo leads under the board towards the back. Seems to work well though, connected telemetry to RX3, and now BF has amperage/temperature/rpm data. Also designed a TPU xt60 mount available at: https://www.thingiverse.com/thing:2947877