As usual, I had the urge to design and build a new UAV airframe in one day. I woke up this morning and the gears in my head began turning about a new simple airframe design, so I started like I usually do with a sketch. I then moved on to cutting the basic shape out of a sheet of blu-core foam, making 2 pieces total then glueing them together with some gorilla glue. I also created a elevator and rudder using 1/4 in. foam board. Next I sanded the fuselage to make it more round and added the elevator, rudder, and balsa motor mount with outrunner motor. I also cut out the areas for the flight equipment. After all of that I added the neccessary radio equipment and wing mounting hardware to complete the building process.....just have to set the trim and wait for a good day to conduct a test flight.
When I conducted the test flight It turned out to be very slow and stable. I came to the conclusion that it was definately underpowered so I replaced the small 20-30oz outrunner to a electrifly rimfire outrunner 30-35-1250 which is capable of flying aircraft up to around 4 lbs which is right at my max allowable weight. I also upgraded to a 10x6E folding prop with a 55mm hub by APC and 50mm aeronaut spinner. I redesigned the motor mount to allow the motor to actually mount on the inside. I also made an air scoop just below the motor mount to help with cooling the motor/esc/battery.
Air Intake front view
Air Intake Batt. compartment view
Since the original post I have also put the PicoPilot into it own enclosure which makes mounting the reciever a little easier and also helps isolate and protect the autopilot.
I have also finally installed the Data Transceiver. I used a pair of Aerocomm CL4790-1000-232 transceivers, one removed from its enclosure for the UAV and one still enclosed for the base-station. I chose the Aerocomm data transceivers because of their ease of use and the already integrated RS-232 serial port, which made a plug and play interface for the GPS.
Data Transceiver and antenna
The GPS receiver was embedded in the top of the wing and covered with strapping tape, as is the majority of the bottom side of the wing and the fuselage for added strength and durability. The final weight minus imaging/video equipment came in at 2lbs 6.75oz
Name: MRASV-3 (Medium Range Aerial Surveillance Vehicle / Ver. 3)
Weight RTF: Under 4lbs
Autopilot: UNAV Picopilot NA (32 WP Navigation / ALT hold)
Duration: 30min @ 30mph cruise speed (just below 1/2 throttle)