I shall use this post to add some descriptions about my ArduPilot airframe, the SIG Kadet Senior BIY kit converted electric. I'll add tids and bits of this work in progress started last autumn once in a while, when timetable permits.
As a starter, I think it's interesting to say that this airframe now flies! I maidened it this last sunday and I must say, after three flights and excepting a little mishap on the third landing approach, I am more than happy with the result and glad to go on with developing to a full ArduPilot platform.But for now and before I expand this post, here a short video of the first maiden takeoff.
Next is a short footage of the second maiden takeoff illustrating that e-power is fine and plenty. I run a 560 RPV brushless outrunner, a 100A ESC, a 6 cell lipo battery with 9000 mAh capacity, all of Chinese manufacture (the lipo is a custom order, though). The propeller size a 11x7''.Next video is showing some aerial action. I am not a good pilot, so do not expect perfection here...By the way, I wish to thank my colleague and friend Claude for having handled the camera that maiden day.More is to come, so stay tuned!---------------I worked on preparing ArduPilot and other components like my pan & tilt video camera, my "Nunchuck Headtracker", and my OSD. As I have written in another post, I intended to have a spare ArduPilot board (old version) used only for Xbee reception from headtracker/photo shutter and, additionally for parsing data needed by he OSD. I struggled a lot with multiple instances of NewSoftSerial to handle the data flux. After some rethinking, I decided to simplify the setup and processing by this spare ArduPilot board. So I included an Arduino Pro Mini (3 computers in the plane because I am a too bad coder!!!!). The spare ArduPilot will act as Xbee reader, pan&tilter for the cam, and photo shutter for the 10Mpixel digicamera. the additional Arduino Pro Mini will just receive data from the autopilot (ArduPilot 328) and parse what is needed to the Inspire video OSD. So I need no soft serial in the chain of operation. Since I made the step adding the Arduino Mini, everything runs as expected.The photos will be taken down vertical from a bay inside the fuselage. The Kodak digicamera stays in place with small strong magnets (easy to take out and very precise lock in place) and is activated mechanically by a 5g servo (I did not hack this camera for electric shutter yet as I've done with a preceding 5Mpixel before). The shutter servo is linked to the OSD which has a shutter connector and can be programmed to do time lapsed shot. the cam is slow to store high res pictures (about 4-5 seconds each), so I programmed the OSD to take a shot every 10 second. The OSD will write the GS location and a autonumber to its memory with every shot, which is nice. It also has a shutter input connector for RC triggering. So I will connect this input to the spare ArduPilot (pan&tilt&photo) on its 3rd servo channel, so I'll be able to trigger pics with the Nunchuck handle in between time lapsed photo shots. I'll modify my code for this additional function tomorrow evening, because it came to my mind today that I can actually combine time lapsed and manual trig. Before I thought I had to chose between both solutions.So all this is not much about the Kadet Senior. On the airframe itself, I've mounted my video transmitter with antenna. It is in the middle of the fuselage, just behind the wing trailing edge bolts. Tonight I've also mounted the small microphone (with basic amplifier) I got from Hong Kong through Ebay for a pair of bucks or so. To isolate it a bit from the noise and air flux inside of the fuselage (needed in an E-converted plane to keep things cool), I decided to follow a suggestion from a colleague and mounted the microphone inside a ping-pong ball! I cut open a triangular hole in such a ball with my acto knife, kept the triangle, stuffed some make-up cotton (thanks to my wife) inside the ball (not too much, not too tight, though), inserted the microphone tip to the ball center and glued on the cut to shape triangle door with some plastic modeling glue (the one that smells like my childhood!). On two opposite sides of the ball I glued some folded piece cut out from another ball and could finally mount the microphone ball in the tail part of the fuselage behind the control servos, far from the motor and prop noise. I used to elastic bands attached to the folded slots to finally have the ball with no direct contact to hard and vibrating fuselage parts. Maybe I will hear the sky instead of just the engine!!! Or maybe not... we'll see.Promised, tomorrow I'll do some pics to illustrate all that for those who don't like or have time reading long posts.And i the future, when time permits, I'll try to give some more details about solutions adopted for the airframe (tray for the 1.3kg lipo battery, cooling hatch for the ESC, double switch to avoid sparks when powering up, video battery in the wing to counterbalance pan&tilt camera, electric wing connections through RS-232 connectors, etc.---------------For those interested in Xbee RSSI signal monitoring in Arduino/ArduPilot, I've described what I've just implemented in my setup in a separate post.---------------
One of the lipo pack I use is a 2 x 6s 4000mAh saddle. I got them from Ebay for a quite reasonable price.
Of course lipo weight is as much as 1.1 to 1.3kg. The full loaded airframe is something like 5.7 kg. I think it is ok up to 6kg. I also designed the wing assemblage to be able to accommodate a wing span extension in the center if that is becoming an option in the future.
Nice flying...! Hope to report similar this weekend. Also curious how your airframe specific PID setting for ArduPilot will turn out. Thanks for the post.
Comments
Of course lipo weight is as much as 1.1 to 1.3kg. The full loaded airframe is something like 5.7 kg. I think it is ok up to 6kg. I also designed the wing assemblage to be able to accommodate a wing span extension in the center if that is becoming an option in the future.
What kind of weight do you think it will carry?