After watching all mini FPV quadcopter racing videos, I couldn’t wait to build my own. My aim to build a 250 size FPV quadcopter for under £250, camera and video transmission kit included.
The gear I have chosen:
- Frame: Diatone FPV 250V3 | £11.50 from unmannedtechshop
- Power Distribution Board with two BEC outputs – one of which is adjustable | £4.99 from unmannedtechshop
12Amp SimonK 1 with a Bec and the rest are Opto isolated | 4 x £7.30 from unmannedtechshop12Amp BLHeli EMAX | 4 x £5.91 from Banggood
- Motors: EMAX MT1806 | 4 x £9.42 from Banggood
- Flight Controller: CC3D Firmware 14.10 | £11.08 from Banggood
- Propellers: 5×45 Triple blade as well as a variety of 5030 and APC 6040 | 4 x £0.87 from hobbyking
- Mobius Wide Angle B Lens Action Camera | £48.90 from hobbyking
- 2 x Turnigy nano-tech 1500mah 3S 35-70C Lipo battery | £10 from hobbyking
- FrSky X4RSB 3/16ch 2.4Ghz ACCST Receiver | £17 from hobbyking
- FrSky FLVSS LiPo Voltage Smart Port Sensor | £10 from hobbyking
- Signal loss Alarm & Lost Plane Finder | £2.83 from hobbyking
- FT952 FPV 5.8GHz Video TX 32Ch 200MW | £17.80 from Banggood
- 5.8GHz Circular Polarized Antenna SMA (Set) (Short) | £7.18 from hobbyking
- SMA Jack < – > SMA Plug 90 Deg | £2.86 from hobbyking
- Mobius USB to AV Out FPV cable | £2.18 from hobbyking
- 1 Red & 1 Green LED Strip for 3S battery | 2x £2.76 from Banggood
- Diatone Glass Fiber 5030 Propeller Protective Guard | £3.46 from Banggood
- MinimOSD | £7.62 from Banggood
The cost for all of the above comes roughly at around £250.00
In addition I use my existing transmitter, charger and FPV monitor:
- Taranis X9D transmitter | £134.00 from Hobbyking
- Black Pearl 7″ FPV Diversity Monitor (5.8ghz, 32 Channel) | £160 from unmannedtechshop
- Hyperion Balance charger (good alternative if you are looking for one would be the Turnigy Reaktor 300W 20A) £40 from Hobbyking
For the build you might also need the following tools and accessories:
- Soldering station with a fine tip and soldering iron
- Dremel or similar hobbyist multi purpose rotary tool
- Your favourite battery connectors (I use EC3) and JST connectors for the VTX
- 160pcs M3 Nylon Black M-F Hex Spacers Screw Nut Assortment Kit
- Moongel / Stagg gel vibration damper
- 14AWG red & black silicone wire
- Wire Stripper / Cutter
- Aluminium foil tape for balancing props
- Red Threadlock
250 quadcopter build video
Building the quadcopter took me around 4 hours. The diatone frame was very accommodating it has space in the middle to fit the distribution board and on top of you can stack more equipment using nylon standoffs.
There were a few modifications I had to do in order to fit everything:
- I had to drill extra holes for the motros
- Drill an opening in the middle of the frame to allow the ESC cables to go through.
- Drill bigger holes for the standoffs to fit
- Cut the base of the box that the motors came in and used it as a plate on top of the standoffs and applied the Stagg gel damper on which I then placed the CC3D Flight Controller.
- Had to drill some new holes for the propeller guards to match the motor base hole orientation.
The total weight of the copter with the battery is currently 630 gramms which is slightly on the heavy side
Some more pictures after further modifications with more to follow …
FrSky X4R wouldn’t bind
The X4R receiver didn’t seem to bind with my transmitter so for the time being I am using a spare X6R and I sent the X4R back to the shop for diagnosing.
The issue with my original X4R receiver was that it had the new EU Firmware update while my Taranis transmitter internal 2.4GHz module didn’t have the up to date firmware. So for the time being I exchanged the receiver for one that had the older firmware which is compatible with my transmitter.
I hope that this will save some headaches from other people that may wander why their new receivers don’t bind with their working transmitters as it personally drove me mad until it was picked up by the store I bought the receiver.
Abnormal flip mid-flight
The quad flies well however during sadden throttle application or continuous yaw it seemed to flip. I am still trying to figure out why this is happening and I suspect vibration.
I contacted Unmannedtech who after seeing the video and my description of what I’ve done suggested to try another CC3D Flight Controller. I have received and installed the new controller so I now need to just go out and fly!
Other things I have tried is Calibrating the ESCs, upgrading the firmware, changing the PIDs, applying a little bit more Stagg gell.
Another attempt to fly the quad after replacing the CC3D and following a successful flight on the previous day. It might be time to disassemble and test each motor ESC pair individually.
So after a month of trial and error I have narrowed down the issue to the Speed Controllers (ESC 12A SimonK) – I wasn’t sure which firmware was preloaded in the ESCs but when I replaced all 4 of them with the EMAX 12A BLHeli Escs the quadcopter flew incredibly stably with no issues whatsoever.
Video of the flight, including flips and rolls below 🙂 I am now a very happy man!