Square tubing quadcopter
by RustyPaint, published
This is my first ever medium scale RC aircraft so I decided to try to make it durable and easy to repair.
The base frame is 3/4 inch aluminum square tubing to create the X and all other support pieces are printed ABS.
Using MultiWii platform: http://www.multiwii.com/
Loosely based upon these videos:
Video of it in flight:
Update 8/30/2013, added FPV components.
Lighter weight version using Poplar Squares here:
These parts used 20% honeycombe fill in ABS:
These parts need to be stronger, so 40% (or more) line fill in ABS:
These parts are nice to have semi transparent to see the status LEDs, so 20% honeycombe fill in PLA:
Non printed parts
2 foot lengths of 3/4 inch square aluminum tubing x2
m3 nuts x8 (4 used as jam nuts)
8 button head 1.5 inch length x24 (m4 can be used)
8 nylon capture nuts x24 (m4 can be used)
8 washers x32
4 button head 1.25 inch length x8 (m3 can be used)
4 button head .5 inch length x8 (m3 can be used)
4 nuts x32 (16 used as jam nuts) (m3 can be used)
4 washers x8
3/8in x .171in x 1in Nylon Spacers x8
Red and Green electrical tape
Flight board with straight pins: http://witespyquad.gostorego.com/flight-controllers/multiwii-pro-2-0-flight-controller.html
Parts from hobby king:
On Board Lipoly Low Voltage Alarm (2s~4s)
Turnigy D2836/8 1100KV Brushless Outrunner Motor x4
HXT 4mm to 4 X 3.5mm bullet Multistar ESC Power Breakout Cable
HXT 4MM to Banana Plug Charge Lead Adapter
Lithium Polymer Charge Pack 25x33cm JUMBO Sack
10x4.5 SF Props 2pc Standard Rotation/2 pc RH Rotation (Green)
10x4.5 SF Props 2pc Standard Rotation/2 pc RH Rotation (Red)
10CM Male to Male Servo Lead (JR) 26AWG (10pcs/set)
TURNIGY Plush 30amp Speed Controller x4
PolyMax 3.5mm Gold Connectors 10 PAIRS (20PC) x2
TURNIGY BESC Programming Card
Turnigy Accucel-6 50W 6A Balancer/Charger w/ accessories
Turnigy 9X 9Ch Transmitter w/ Module & 8ch Receiver (Mode 2) (v2 Firmware)
Turnigy 4000mAh 3S 20C Lipo Pack
Read http://www.multiwii.com/ to understand hooking up and programming the flight controller board.
Notch the 2ft length square tubing so that they fit at their centers at right angles.
Weld them together for extra strength.
Sandwich with center.stl x2. Drill holes and mount with #8 bolts, washers, and nuts. You can just use 4 bolts if you welded the tubing together.
Space out mount.stl x4 so they are equal distance from each other along each arm. You may want to check for wire lengths to ensure fit. Drill out holes and mount the outrunners with #4 bolts, washers, and double up the nuts on each bolt to jam them in place.
Zip tie the radio RX module to the bottom of housing_base.stl. Put flight controller board inside of housing_base.stl and cover with housing_top.stl. Use m3 bolts and double the nuts to jam them in place. Use servo leads to connect the RX module to the flight controller board.
Mount the housing_base.stl to the top side of center.stl using nylon spaces, #8 bolts, and capture nuts.
Mount bat_holder.stl so that the smooth side faces down (away from center.stl) with nylon spaces, #8 bolts, and capture nuts.
Pair up foot.stl with each other. With each pair, put foot_pin.stl in the last hole of the two legs so that they are joined together (as pictured).
Mount on the square tubing near the motor mounts using #8 bolts, washers, and capture nuts.
Solder connectors on the speed controllers and zip tie them to the tubing after connecting each motor.
Feed the 4 way power connector between center.stl and bat_holder.stl and zip tie to one of the spaces. Connect the speed controllers.
Zip tie the antenna from RX to nylon spacer.
Add colored tape to arms to help you figure out direction.
Mount battery alarm with zip tie.
Program your speed controllers for fast updates and as NiCad to disable low voltage cut of.
Figure out the proper direction of rotation for the motors and switch two wires on motor if they are wrong. Connect to flight controller. Calibrate speed controllers using fight controller (very important they must be calibrated).
Mount props to motors after balancing them. Mount battery with Velcro straps.
This copter is bit on the heavy side but still very powerful. Fly with care. Adjustments for the PID vales will be needed since the defaults are not adequate.
I'm getting close to 10+ min flight time with the 4.0 Ah battery.
One of each:
Mount the sony board camera using servo screws in the holes provided, you may need to drill depending on your slicer software. Mount so that the bracket is on the side of the lense. You may want to file parts that get too close to the surface mount components.
Drill out holes in the servo arm so they match up with the holes on the side of the camera mount. Do a test fit.
Drill out the holes (if needed) for the servo mount (camera_pivot.stl). Mount to the arm with zip ties. Center the servo. Put the modified arm on the servo (slight pitch down). Mount the camera bracket. Mount the servo. Connect the servo to the fight board designated for camera pitch (auto leveling).
Put some foam tape on the back of the video transmitter (thicker stuff near the plugs). Stick it to the tx_mount.stl. Zip tie it down. Use a file to notch the printed plastic so the zip ties don't move. Zip tie the mount to an arm on the quad.
Use thick foam tape to mount the minimosd (if equipped) to the base of the mount.
http://www.thingiverse.com/thing:10541 pins.scad is needed for foot_pin.scad.