QuadCopter by the Moonlight
This photograph wastaken by Nick Sage at our Christmas club meeting at the LDMFA field. It shows my MWC Quad hovering with the moon partially covered by cloud in the back ground.
Tuning for auto-level – MWC Quad
According to the instructions on multiwiicopter.com the mid and endpoints need to be set properly to ensure auto-level works properly. I hadn't bothered much with this except to make sure the throttle travel was low enough to arm the PARIS board. This is probably why I've spent so much time stuffing around with trimming flights trying to get the perfect autolevel hover. After so many trimming flights, I thought it would be good to go back to basics and start from the ground up. Especially since I've just finished assembly of the new Scarab Quadcopter, now is a good time to get things right.
Setting the low point to 1095, the midpoint to 1500 and the high point to 1905 is achieved via sub trim and end point adjustment (on my Futaba 10CAP). The first step is to get the midpoint right at 1500. For this example, I'll assume a working connection between your PC running Multiwiiconf software and the Paris board.
- Center all the transmitter sticks and trims.
- Read the values from the MWC software. They should be close to 1500.
- On the Futaba 10CAP, hold down MODE, then Sub Trim and adjust all 4 channels to as close as possible to 1500.
- Then use the END POINT function on all four channels to high and low point to 1905 and 1095 respectively. Using the elevator as an example, pull full back on the elevator stick and read the value in the MWC software. Hold the stick there while adjusting END POINT so the readout shows 1095. The push the elevator stick on the tx to the other extreme and use END POINT to adjust the readout in MWC to 1905.
- Repeat the process for the other three channels.
- Go fly and see what happens. In my case I'm getting a bit too much oscillation when I activate auto-level that I'm sure can be solved with some PID tuning. I also seem to get the occasional glitch where it seems two motors drop RPM just enough to cause a small drop in altitude. I'm not sure if it's actually a drop in RPM or vibration as I reckon I can perceive a slight amount of vibration. Come to think of it, those two booms are the ones missing one of the four screws in the boom holder because the shafts thread was stripped or non-existent. I do have two spares that came with the kit so it looks like I'll have to go back, disassemble and replace those shafts.
MWC Quadcopter – Cramming in the ESCs
These photos show the frame starting to come together. The bottom of the CF plate shows each of the four ESCs are held in place by 2mm cable ties. There's not a lot of room left on the top of the board after the ESCs and power distribution cable is laid down. On top of this will come the three leads from each motor to plug into the ESC. If you were thinking of using any gauge wire heavier than 20AWG, you might want to think again because even just space will become an issue.
The next plate above is prepared with nylon mounts to host both the MWC control board and above that will be another quad frame plate that is likely to host my GoPro camera. I haven't decided yet whether to put the camera up on the top plate or out in front on an extended arm. Up top under a dome would be better balanced and protected, but out on the arm might have a better view clear of the props. Undoubtedly I'll end up trying both but seeing as I don't have the extended arm, and it costs more money, I'll see how it goes up top first.
Quadcopter Scarab – Power Distribution lead
These photos show the power distribution lead made as per the instructions that come with the Scarab 12 - Quad-X Euro frame. The wire is 20 AWG from HobbyKing. About 15mm of the silicon jacket is stripped from the end of five wires per polarity (red & black). Then the bare wire of each group of five is twisted together. Some 5mm heatshrink helped keep the leads together while being soldered. The result fitted nicely into the terminals of an XT60 connector. I used four micro-deans at the other end to connect to the ESC and one JST connector to hookup some strip LEDs.
QuadCopter SCARAB – Motor Mount Retainer
These photos show the retaining screw cut to 7mm and how it penetrates one quadrant of the 12mm aluminium tube divided up by the motor mount. Cut to the right length, it doesn't intrude far enough to cause concern with rubbing on the wire from the ESC to the motor which is routed internally along the tube.
QuadCopter SCARAB 12 – Assembly part 2
The frame looks well laid out, light weight and just plain good looking. 20AWG is used to connect to the 2213N 800Kv Brushless Motors with just enough left hanging out the end to connect the four speed controllers ( TURNIGY Plush 12amp (2A BEC) BESC ). The only thing I'm unsure about so far is the sorta sharp edges of the aluminium booms and how that might rub against the wires.
SCARAB 12 – Quad-X EURO Build – Motor Mounts
I'm going to try using 1.5mm cable ties on the motor mounts. Seemed to work fine on the Tricopter and in the event of a crash, there might be some give before things get bent.
Canola from the air
It seems every second field is full of Canola around Shepparton at the moment. Here's a few quick ones I took on the way to the Mammoth Scale Fly In at the Valley Radio Flyers.
I did lose the quad once, quite deep in the canola field and thought I could be searching for quite a while but I took the transmitter with me while searching and gave the throttle a little blip every now and again and found it fairly easily.
$20 Quadcopter frame, test flight video
The $20 Bunnings quadcopter frame is a bit heavy, about 400 grams but its straight and strong. The control board is a MWC Paris V4 board with WM+, BMA180 and BMP085 sensors. All up weight is about 1300 grams with the 2650mAH nano-tech 3S lipo. Flight time just hovering was 10-11 minutes.
http://www.youtube.com/watch?v=WzN8wmxWW2s
Connecting the BMP085 Baro to the MultiWiicopter Paris V4
The BMP085 Barometric Pressure sensor is mounted on the bottom side of the Paris V4 board. Orientation of the BMP085 is not important but vibration is always an enemy so I used double sided foam tape to mount it. There are four points from the BMP085 that must be connected, VCC, GND, SDA and SCL. In this case they're connected to the LV I2C pads on the bottom side of board to the same points that the BMA180 Acceleromter is connected to on the top
Yellow wire is SCL. White wire is SDA. Red VCC and Black GND.
