Updated on March 7, 2016
This is the second installment in my drone building saga. For those interested, check out my hexcopter build, Blackout Mini Hexcopter. I wanted to try the ZMR250 quad since it looks like they are lighter and fly more precisely. At least once the aircraft is configured appropriately. If you are entirely new to flying I recommend starting with a Hubsan X4 quad since crashing larger drones is costly and requires significant effort to repair. Make your mistakes on lower cost aircraft.
This is an advanced project. Anyone uncomfortable with computers, software, and using a soldering iron should probably stay far away from this hobby.
Parts List, ZMR250 Quad Multi-Rotor Aircraft (current build)
ZMR250 Carbon Fiber Airframe: UBAD Kunai PCB,Tiger T-Motor MN2206 2350kv (x4) (banggood.com frame, motors anywhere you can get them)
ESC: KISS 20A v1.4 (x4) *KISS ESC's are awsome! No firmware flashing required (or supported). Support for both PWM@500hz and Oneshot125. I'm running Oneshot125 it's great!
Battery: RMRC Orange Series1300mah 4S 60C Lipo (readymaderc.com)
Prop: DAL 5x4.5 v2 CWx2/CCWx2, 1 set shipped with each unit, what a concept (rmrc.com)
FC: Abusemark Naze32 Acro Version running Cleanflight v 1.11.0
Receiver: FrSky D4R-11 4-ch 2.4 Ghz/ flashed to 27ms 8-CH (hobbyking.com) 
FPV Camera: 600TVL Sony Super HAD CCD D-WDR Color Board Camera with OSD Menu DNR
FPV TX: 5.8 GHz 600mW FPV Race Band from ImmersionRC
DVR Camera: SJCAM SJ4000 (GoPro clone, bh.com)
Standoffs & Misc: Bluetooth Mini LE module (Blackbear Labs) required for Apple BT support, antenna: 5.8Ghz SpiroNet RHCP antenna from ImmersionRC, battery straps: Scorpion Lipoly Lock Strap 205mm (1 ea x 3 Small), 3D printed vented Uni-Spacer, blue 1ea (eBay or Shapeways), 3D printed 10 degree motor mounts (droneplastics.com).
I learned a few things from the first build. My original 30A ESC where way too big and didn't fit on the aircraft frame properly. I wanted something smaller so decided to go with smaller and popular KISS ESC's. I eliminated the OSD. The OSD is mixes the telemetry with your video signal to provide helpful information throughout your flight. The flight time on these small aircraft is around 6-10min and they fly far too fast to be watching the daisy's. I found I was not paying attention to the OSD anyway. I also improved the video and moved to 5.8Ghz system. Race drone technology is always improving and since I started about 1 year ago the video systems have improved. The race band transmitter allows up to 32 aircraft to fly together. Since I dropped the OSD I downgraded to the Naze32 Acro edition. An unintended consequence is that the Full Naze32 has extra memory for the Blackbox feature. So even if you don't care about the extra telemetry you may care about using Blackbox. An ancillary benefit of the video frequency change is that the antennas are much smaller using 5.8Ghz. ImmersionRC makes a great transmitter as well with built-in filtering and voltage regulation. Unfortunately, it's also hugely overpriced just like their OSD.
|Photo 1: 1st aircraft build (click to expand)|
|Photo 2: UBAD Kunai PCB board|
|Photo 3: Top view|
|Photo 4: Bottom view, almost finished|
|Photo 5: Configuration of flight control software|
|Photo 6: Finished Aircraft|
Photo 6 is the finished aircraft with LEDs. The LEDs are super bright. I tried a quick hover test just before sunset but my Fatshark goggles ran out of charge. I don't really need them for hover testing anyway. The aircraft flew rough with high speed oscillations. The heavier the thrust the more severe the oscillations. I'm thinking the PIDs configuration settings, specifically the P values, are too high. I am pretty optimistic about this aircraft build. A small word about Finished caption on Photo 6. When you get into this hobby you will find you are never really finished. There is always some improvement to make. Perhaps a better description is flight worthy. I plan to post some updates in the future. Like my maiden flight.
Video 1 is the maiden flight. I had a number of configuration issues along the way. Finally got the major bugs worked out.
Video 1: ZMR250 quad maiden flight
Video 2 is a little more interesting. I few more flights under my belt. My PID configuration needs some slight adjustment since I change the props from 6x4.5 to 5x4.5x3, a tri-blade design. Anytime the power to weight ratio changes it messes with the configuration.
Video 2: ZMR250, a more interesting flight