I built this Lumenier QAV-PIKO as a quieter/stealthier alternative to my 5" quad, for flying in tight spaces. I was drawn to the PIKO because it was one of the smallest/lightest options for 3" props, and looked like a fun build (slightly challenging).

I really love the way this build turned out. Weight is 85 grams without battery, and the all up weight is about 137 grams with the 3S 650 mAh battery. Light weight is owing to the small (120mm) frame size, 1106 motors, and minimal camera support structure. And though this build favored light weight over all-out performance, it still climbs with authority and moves pretty quick.

I spent most of the time on this build designing the custom camera pod. The space on the stock camera mount was pretty tight, and my RunCam Micro Swift + TX200U had no hope of fitting. What you see is probably the sixth iteration of the mount. It has a 25 degree pitch angle, tailored accommodations for the RunCam + TX200U, zip tie mounts for the receiver antennas, a slot for the XM+ underneath, and room for the camera/VTX wires to sneak inside to meet the FC. The square opening for the camera lens keeps the mount free and clear of the video image, while still protruding a bit past the lens to provide protection. If anyone happens to be doing the same build there are 3D files on Thingiverse and I'm happy to offer the SolidWorks files if you want them to make tweaks.

https://www.thingiverse.com/thing:3698163

Regarding the build, I had a few tips and tricks:

• If you haven't already, check out Etolier's build of the 2" here. Lots of good info. https://rotorbuilds.com/build/13162
• I used the M2 hardware from my FC stack in the M3 holes, rather than drilling out my FC to M3 to use the provided hardware. Too many risks for me to drill out the most expensive component of my build, and it looked like M3 standoffs would interfere with components on the FC anyway. The M2 heads don't seem likely to pull through the M3 holes in the frame, even without washers.
• For tidy motor wires, I used shrink tube to secure them to the frame. But you have to remember to put the shrink tube on before the motor installation.
• I liked the idea of the silicone tubing for mounting the FC (per the frame kit), but ended up using the O-rings included with the FC instead. I used the rigid standoffs between the ESC board and the FC board, because I didn't want relative movement of the two to wear out the stacking connector between those boards.

The PIKO kit doesn't seem to have gotten much love from Lumenier, but I loved the end result so I'd probably buy the same kit again if I stuffed this one. Some of my complaints are:

• No instructions, either online or in the box. You're left to figure it all out from the product description.
• M3 holes for FC. (Really unusual to find M3 holes on a 20x20mm FC stack)
• Rubber pads for camera and battery could have been self-adhesive. (Though a little CA glue was a good alternative)
• Only 1 rubber band for the battery. (Come on, these things wear out and they're a weird size, throw in a dozen)