Betamax Quadcopter

From Marginally Clever Education

Parts & Tools

Misc Parts:

  • 16 M3 Nylock nuts
  • 8 M3x10 Screws
  • 8 M3x45 Screws
  • 1 bag of small zipties

Frame:

Hobby Parts:

Quadparts.JPG Quad-IMG 6409.JPG

(not shown - battery charger, 8xAA batteries in transmitter, soldering iron)

Preparation - Solder board

(WE’VE DONE THIS IN ADVANCE FOR THE WORKSHOP!)

There are two pieces of preparation required for the control board.

first - bridge power source pads. This allows the board to be powered from the speed controller.

second - solder pin headers to input pins.

Motor Mounts

Mount the motor plate to the motor. It uses four small screws, countersunk to sit flush and is laid out in an unequal cross pattern, so will only mount in one orientation.

Repeat for all four motors.

Quad-IMG 6410.JPG Quad-IMG 6412.JPG Quad-IMG 6414.JPG Quad-IMG 6416.JPG

Prop Adapter

The prop adapter has three pieces - the threaded shaft, the unthreaded base piece, and the screw on cap. Slide the threaded shaft over the shaft of the motor, and slide the flat base piece on, flat rough side away from the motor.

Repeat for all four motors.

Quad-IMG 6418.JPG Quad-IMG 6419.JPG Quad-IMG 6420.JPG

Prop

We included four packs of props in the kits - two of the packs rotate clockwise, two rotate counterclockwise. Mount one of each kind of prop.

  • It is important to mount props the correct way up - there is small text on the blades, near the hub, which face UP *

Repeat for all four motors.

Loosely attach the cap to keep things together, we’ll be removing it later.

Quad-IMG 6421.JPG Quad-IMG 6422.JPG Quad-IMG 6423.JPG

Arms

Each arm uses one arm plate, two arm walls, eight zipties, and a foot.

Quad-IMG 6426.JPG

Fit the arm walls to the arm plate. The circular side of the arm walls goes to the circular side of the arm plate.

Quad-IMG 6427.JPG

ziptie the walls together, across the plate. Use one ziptie across the top, and one across the bottom, meeting at the sides, for best handling in crashes.

ziptie both spots on the walls.

Quad-IMG 6428.JPG Quad-IMG 6429.JPG Quad-IMG 6430.JPG Quad-IMG 6431.JPG Quad-IMG 6432.JPG Quad-IMG 6433.JPG

slot the foot into the bottom of the arm plate. feed one ziptie from the lower slot on the foot though to the top of the plate, and one through the higher slot to the other side. Tighten a second ziptie to the top of the plate for each to lock them.

Quad-IMG 6434.JPG Quad-IMG 6435.JPG Quad-IMG 6436.JPG Quad-IMG 6437.JPG Quad-IMG 6439.JPG Quad-IMG 6440.JPG Quad-IMG 6441.JPG

Trim the ends off the zipties.

Repeat for all four arms.

Quad-IMG 6443.JPG

Mount Motors

Thread two M3 screws through the motor mount plate, on opposite sides of the motor.

place the plate and screws through the holes on the arm, with the wires from the motors facing inside the arms.

Thread a locknut onto the screws, and use a screwdriver and pliers to tightly screw the motors to the arm plates.

Repeat for all four arms.

Quad-IMG 6444.JPG Quad-IMG 6445.JPG Quad-IMG 6446.JPG Quad-IMG 6447.JPG Quad-IMG 6448.JPG Quad-IMG 6449.JPG

Top Plate

Peel one side of the foam tape, and stick it to the center of the frame. Peel the other side, and mount the Flight controller to the top plate. Try and get it as close to centered as possible.

  • IMPORTANT - the arrow on the flight controller points ‘forward’ for the quad. See the photos for the correct orientation of the board with respect to the rectangular holes cut in the frame. *

Peel one side of the second piece of foam tape, and attach it to the bottom of the receiver. Mount it to the rear of the top plate, orientated as shown in the photos.

Quad-IMG 6451.JPG Quad-IMG 6452.JPG Quad-IMG 6455.JPG

Bottom Plate

Thread the battery strap through the inner two rectangular cutouts in the bottom plate. Test fit by sliding a battery through the tape. You can feed the excess battery strap through one of the other rectangular holes.

Quad-IMG 6456.JPG Quad-IMG 6457.JPG Quad-IMG 6459.JPG Quad-IMG 6460.JPG

Battery Connector.

Solder a yellow XT60 male connector to the connectorless black and red wire on the speed controller.

Make sure to put heat shrink over the wires first!

The two sides of the connector are marked + and -. Solder the black wire to -, and the red to +.

Use the heatgun to shrink the heatshrink over the soldering.

  • IMPORTANT SAFETY NOTE - if the two sides of the connector were to short while a battery is connected, a fire is likely to result. It is _extrememly_ important that they are not shorted, and well heat shrunk. *

Electronic Speed Control

Lay the speed controller and top plate out as shown in the photos. You want the text on the speed control facing up, with the control and power wires of the speed controller on the ‘‘front’ side of the top plate.

Separate out the four sets of three wires, moving one towards each corner.

Quad-IMG 6462.JPG

Feed two pairs of zipties through two pairs of small holes on the top plate. loosely tighten them - you want enough slack to side the speed controller through on the bottom.

thread the small colored wires with connectors through from the bottom of the top plate - they will come out the inner left rectangular cutout, relative to the front of the top.


Quad-IMG 6463.JPG Quad-IMG 6464.JPG Quad-IMG 6465.JPG Quad-IMG 6466.JPG Quad-IMG 6467.JPG Quad-IMG 6468.JPG


Connect the four wires as shown -

  • IMPORTANT - the photos of these wires are WRONG and are pending updated photos. SWAP THE ORANGE AND BROWN WIRES FROM HOW THEY ARE SHOWN IN THE PHOTOS!

From front to back, with the indicated color to the middle of the board. - brown - red (single) - white (black to the outside, red to the middle) - orange (three of the connectors only have one wire - this is expected)

Quad-IMG 6469.JPG Quad-IMG 6470.JPG Quad-IMG 6471.JPG

Attach the speed controller to the bottom of the top plate, text to the top, power connector to the front. Tighten the zipties.

Quad-IMG 6472.JPG Quad-IMG 6474.JPG Quad-IMG 6475.JPG

Receiver wiring

Attach the wires as shown from the receiver to the control board.

order on board side, from front to back - (we discovered that not all kits came with the same colours of wires - but annoyingly all seemed to have at least one duplicate. The color of wire isn't important, just duplicate the pattern The red, white, and black wires are attached, please do orient them as indicated )

- yellow - grey - brown 1 - brown 2 - white - red - black (white red and black will be attached to each other)

Receiver:

- Channel 1: yellow to the top - Channel 2: white to the top, red to the middle, black to the bottom - Channel 3: Grey - Channel 4: Brown 1 - Channel 5: Brown 2

Quad-IMG 6473.JPG

Mount arms

Thread two long M3 screws through the top plate, the two holes on the triangular side of an arm, and the bottom plate. Make sure the motor faces up! (don’t worry about which arm - we’ll be confirming motor direction and prop choice later)

* important - make sure none of the motor wires are pinched between the wood layers! *

use pliers and a screwdriver to attach a locknut. Tighten until firm, but don’t overly bend the wood.

Repeat for all four arms.


Quad-IMG 6476.JPG Quad-IMG 6478.JPG Quad-IMG 6479.JPG Quad-IMG 6480.JPG Quad-IMG 6481.JPG Quad-IMG 6482.JPG Quad-IMG 6483.JPG Quad-IMG 6484.JPG Quad-IMG 6485.JPG Quad-IMG 6486.JPG

Wiring

Tuck the antenna under the ziptie on the nearby arm. Thread the three wires under the zip ties on each arm. Make sure that the correct (closest on the speed control) are running to each arm. Connect the bullet connectors on each arm to the motor. Don’t worry about the order.

Push the excess wire through the hole in the arm.

Quad-IMG 6488.JPG

Calibrate ESC, Program and Calibrate the board.

Prior to ESC callibration, ensure props are removed!

We've prepared a version of the MultiWii for the sensors and configuration of our boards and quads. Download the bundle. Unzip it.

Use a mini usb cable to connect the flight controller board to the computer.

Open the Arduino IDE,

open the file MultiWii.ino from inside the MultiWii folder in the downloaded project.

Connect to the board. Use the board setting "Arduino Leonardo". The port will depend on your computer.

  • IMPORTANT: DO NOT HAVE THE BATTERY CONNECTED WHILE PROGRAMMING FROM THE ARDUINO IDE

open the file config.h in the arduino ide and search for the section "ESCs calibration" (line~1017)

Line 1026 will be:

   //#define ESC_CALIB_CANNOT_FLY  // uncomment to activate

uncomment the line, change it to

   #define ESC_CALIB_CANNOT_FLY  // uncomment to activate

Save the file, compile and upload to the board. This will put the board into a mode where it will attempt to put the ESC into callibration mode, then show it the maximum and minimum throttle points. The motors should not spin up when powered up, but if entering callibration mode is unsucsessfull, it may behave in an unanticipated manor- HAVE THE PROPS REMOVED!

unplug the USB cable. connect the battery to the quad. Lots of beeping will be heard. Wait at least 60 seconds, then unplug the battery, and plug back in the USB cable.

in the arduino IDE, in the same config.h file, change line 1026 from

   #define ESC_CALIB_CANNOT_FLY  // uncomment to activate

back to:

   //#define ESC_CALIB_CANNOT_FLY  // uncomment to activate

and compile and upload.

The board is now in programmed for normal multiwii use.

Quit the arduino IDE.

From the same code download bundle, open multiwiiconf folder, choose the appropriate platform folder for your computer, and run MultiWiiConf.

in the left hand column, choose the same port as you used in the arduino IDE. click the green 'START' button. The white graph area should begin scrolling, and the lines will react if you shake the quad.

Set the quad on a level untouched surface, and leave it steady. Click the "CALIB_ACC" button in the middle of multiwiiconf. Wait 30 seconds, without touching the quad. This calibrates the quad for your specific accelerometer, and needs to be re-done if you reload the board from the arduino IDE.

Sanity check - the dials in the top right of multiwii conf relect the roll and pitch of the quad. move the quad around, and verify that the dials change as you expect - if you tilt it up and backwards, does pitch angle get increasingly negative? if you tilt it to the right, does the roll angle increase?

click the green "read" button, to read the default configured PID and stabilization settings for the board. change the values to match the following chart:

Multiwii.png

It's worth noting that multiwiiconf is a somewhat aggravating application, and you may need to click multiple times to have your intended effect in the stabilization settings grid.

To change the PID values, click on the cell you wish to change, and drag the mouse left or right. Bizarrely, typing in values is not accepted.

THESE SETTINGS WILL NOT TAKE EFFECT UNTIL YOU CLICK THE GREEN "WRITE" button. - do so.

to verify, click the read button again - the values should stay at what you set them.

Setup transmitter

Power on your transmitter. If it beeps "switch error", make sure that all toggle switches on the front and top of the transmitter anre pushed AWAY from you. The radio should stop beeping and display "TURNIGY" in large text.

Press the menu button, and enter the Settings menu.

scroll to "[TYPE SELEC ] and hit menu.

Select ACRO (image of a plane), and hit menu.

Press exit, and select the FUNC SETTINGS menu. Select [E. POINT].

This is an odd menu - the left right column selection is controlled by the position of the two sticks vertically, while the D pad is used to select row, and change values. Hold the + button on a value to set it to 120%.

Set: - AIL to 120% 120% - ELE to 120% 120% - THR to 120% 120% - RUD to 120% 120%

Press menu to save and exit.

Enter the [AUX-CH] menu.

Set CH5 to "GEAR" - this is the small switch on the top right shoulder of the transmitter.

Press menu to save and exit.

Enter the [SUB TRIM] menu.

set the left stick to the middle position. The right stick should snap to this position automatically.

look at the bar graph in the multiwii GUI. We need to centre the THROT, PITCH, ROLL, and YAW values to 1500 by adjusting the trim on the various channels. There is a small delay between changing a value on the transmitter, and the value shown in multiwii conf changing - change in small steps, and give it time to settle before adjusting. Get all four channels to within 1498-1502.

Press menu to save and exit.

Press Exit Exit to return to the main screen.

Check Prop Direction

Props have a proper direction - They should not be run upside down, and the motor must be turning in the correct direction. During this step, we’ll test the direction of the motors, and make sure we have the props correctly orientated.

Remove all props from the motors.

first, make sure all props are sitting right side up - as mentioned earlier, there is small text on the top of the blades, near the hub. Make sure this faces up.

Looking at the blades from the top, you can tell which direction it rotates in you can think of it as the ‘high’ side of the blade hitt the air first, ‘pushing’ the air downwards.

The two pairs are mounted diagonal to each other - the two neighbours of a prop should rotate in the opposite direction, while the prop across the center from it should rotate in the same direction.

the black clockwise prop should go on the back right corner, the black counter clockwise prop on the back left corner. Mount the colored clockwise prop to the front left, and the colored counter clockwise prop to the front right. These colors will help you track the orientation of the quad in the air, but aren’t truly necessary. Don’t attach the screw on prop nuts!

important - we will be powering and spinning up the motors to check the direction in which they spin. If the prop nuts are attached, the props will attempt to rapidly lift the quad - this is dangerous when we do not know if the direction of rotation is correct.

turn on the transmitter, then plug in the battery on the quadcopter. After it beeps, you are ready to ‘ARM’ the quad for the first time. Once armed, increasing the throttle (verticaly moving the left stick) will accelerate the motors.

To arm the quad, push the left stick all the way down and to the right. The red light on the board should turn on. return the left stick to the bottom center.

important - to disarm the quad, push the left stick all the way to the bottom left. do this before approaching the quad.

slowly notch up the throttle, until the motors start spinning. If you get more than half way up without the motors all spinning, stop and troubleshoot.

Throttle down the motors.

Because the props are only sitting on the motors, they will continue to spin once throttled down. check that they are spinning in the direction you expect.

If a prop is NOT spinning in the proper direction, you will need to reverse the direction of the motor. To do this, disarm the quad, and disconnect the battery. Once the quad is disconnected, swap any two wires running to the motor you wish to reverse, and repeat the process.

Once all motors are spinning in the correct direction, you are ready to test fly!

Tighten prop nuts

Use a small screwdriver through the hole on top of the nut, and hold the prop and motor in place.

It is important that you tighten the prop nuts. If they are attached too loosely, they can fly off during flight. Once the nut is tightened, flick the prop and watch it spin. If the motor turns with the prop then it is firmly attached.

Symptoms:

  • The prop spins without the motor spinning.
  • The prop spins but doesn’t seem to generate lift when you try and take off.


Fix: Put a rubber O ring between the prop and the prop nut, and tighten to add grip.


Test motor/board response

  • Caution - this step requires a buddy, and as you will be activating the motors with the props attached and someone holding the quad. the holder must be cautious *

set the quad on a level surface, turn on the transmitter, and plug in the battery.

Once the quad beeps, have someone lift up the quad and hold it level. make sure that the blades can freely rotate, and will not hit the person holding it!

arm the quadcopter, and gently throttle up, until the holder feels the board is pulling.

have the holder tilt the quad down towards each motor in turn. they should feel the quad generate more force from that motor in turn. If not, stop, disarm, and troubleshoot.

tilt the collective (right stick on the transmitter) in each direction in turn - the holder should feel the quad try and move in that direction.

Test flight!

Take the quad outside and try to gently lift off the ground, and set it down.

Auto levelling

The switch on the top left of the transmitter activates and de-activates auto-level mode. If properly trimmed and calibrated, this will keep the quad steadier.