Deadcat SK450 Test Flight

New Quadcopter Build: SK450 Dead Cat

Now that we are back from Florida and parts have arrived, it is time to start the new build.  I salvaged whatever I could from the Flying Flowerpot (may it rest in peace).  Two motors, the four speed controls, battery, flight control, receiver, and camera were all salvageable.  However, I decided to replace some of these parts and to change the configuration of the quadcopter to "Dead Cat" - a non-square quad setup with more room for cameras.  See the picture below for the basic setup, not fully assembled.

The other changes that I plan to make are:

• New flight control system (Pixhawk) with more accurate GPS (LEA-6H).  I bought the genuine 3DR versions instead of the Chinese clones to ensure quality.  My old APM 2.6 system was a Chinese clone and had limitations and unknown quality.
• New receiver (Spektrum AR610).  This receiver is highly regarded compared to the Orange R615X, which has rumors of range issues.  New Spektrum DX6i transmitter.
• Use of a PCB as a frame to distribute battery power, bought from Hobbyking.
• Dead Cat configuration using a conversion kit from Hobbyking.  I made a mistake and assumed that all I needed was the previously mentioned SK450 Dead Cat PCB, but it turns out that you need this plus the Dead Cat conversion kit.
• Full monitoring of power by the control system.  This was included with the Pixhawk.
• A proper cover instead of a flower pot, sourced from Quadrysteria.com.
• Receiver power from the Pixhawk or separate UBEC, not from the ESC's.  This should be higher quality power with less interference.
• Use of loctite on all screws to reduce the chance of loosening with vibration.
• Carbon fiber props.

The new control and radio system are shown below.

Evaluation of Homebuilt Quadcopter Components

I put together a table with my evaluation of the components I used to build the quadcopter and the rough cost of the quadcopter: $320.

Part	Source	Rating (1=best)	Approx cost	Comments
Hobbyking SK450 Glass Fiber Quadcopter Frame 450mm	Hobbyking	1	$20.00	Well documented, rugged
TURNIGY Plush 25amp Speed Controller	Hobbyking	1	$13.00	Well documented, works well, does not overheat, used 4
Turnigy Multistar 2216-800Kv 14Pole Multi-Rotor Outrunner	Hobbyking	1	$16.00	Works well, used 4 units
Hobby King Quadcopter Power Distribution Board	Hobbyking	2	$5.00	Works well but hard to mount
Extended Landing Skid Set for SK450 Quadcopter Frame	Hobbyking	2	$11.00	Works but a bit too flexible
Slow Fly Electric Prop 1045R SF	Hobbyking	3	$3.00	Works, inexpensive, but prone to breakage
TURNIGY BESC Programming Card	Hobbyking	1	$5.00	Well documented, works well
Turnigy 2200mAh 3S 20C Lipo Pack	Hobbyking	1	$10.00	Good power delivery, good value
OrangeRx R615X DSM2/DSMX Compatible 6Ch 2.4GHz Receiver w/CPPM	Hobbyking	1	$10.00	Works well, good value, compatible with Spektrum DX4i Transmitter
HobbyKing HKPilot Mega Mini Combo Flight Controller GPS and Power Module	Hobbyking	4	$120.00	Flimsy USB, poor documentation
5" (inch) Travel Micro USB Cable, Twin Pack Cables	Amazon	1	$10.00	Great way to protect USB on APM
Hobbypower Top Pin APM2.6 External Compass APM Flight Controller w/ UBLOX NEO-6M GPS	Amazon	2	$70.00	Works great, great value, no documentation
Tenergy 1-4 Cells Li-PO/Li-Fe Balance Airsoft Battery Charger	Amazon	1	$20.00	works great, great value
2 of NEEWER® 3.5mm Gold Plated Bullet Banana Plug Connector for RC Battery 10-Pairs	Amazon	1	$7.00	Works well, used 2 packs
Dowels, screws, glue, velcro, flower pot	Home Depot	1	$25.00	Cheaper than hobby store
Total cost of built unit (not including broken Hobbyking Controller)			$319.00

Quadcopter Build - Photos of Finished Drone

The flower pot was the best cover I could find and the bungee cords hold it to the drone

Note the hole so the Controller LEDs are visible

You can see the Vuho camera beneath the drone

Bottom view

Battery mount and USB extender connector which also protects against controller USB damage

Camera mount with battery behind

Love that flower pot!