: This UAV is not functionally very different from GeoCrawler 4
, with its off-the-shelf Picopilot GPS-guided autopilot, but it's so much cooler! If you're going to build a UAV, why not make it look like a UAV? And there's no UAV better looking than the Predator B. The challenge with using scale airframes like this is they're usually not as inherently stable as the high-wing trainers we use for the other UAVs, and they typically don't have as much room inside for electronics. This one is better than most. It's an inexpensive and nicely made ARF from Nitro Models, and with a 63" wingspan, it's got the flight performance of a powered glider.
: Up to 20 pre-set GPS waypoints. Integrated inertial stabilization. Tried and true system, which offers reliability in exchange for limited flexibility. Camera has a programmable time-lapse function, which is best for autogenerating aerial shots to later assemble over a Google maps grid.
Build notes (these refer only to the Nitro Models Predator without ailerons; ie, the one I crashed. Build notes on the current Predator, with ailerons, are here.):
Airframe: Nitro Models Predator ($80, modded with an AXI 2208/34 brushless motor, $70)
- [UPDATE] I crashed that version, in part because the V-tail just isn't enough control by itself and in part because the AXI wasn't enough power. I've now moved back to another Predator model ($67) which has ailerons, and given it a more powerful Hacker A30-28s motor. My post on how to build and enhance it is here. If you do decide to stick with the original Predator without ailerons, you'll probably want to cut off a few inches of the tail, put in a proper motor bulkhead and give it a more beefy outrunner like the Hacker. You might want to extend the area of the V-tail control surfaces, too. It really is hard to control as it is.
- Autopilot: AttoPilot, the most powerful under-$1,000 autopilot.
- Imaging: Pentax Optio A30, which is the smallest high-res camera I've found that allows for IR shutter trigger, plus a Prism R/C-controlled IR trigger. (both are around $200). This is also good candidate for the DIY stabilized camera mount described here, which doesn't require the Prism trigger, although note that you'll need to build the version with the Futaba "Pilot Assist" sensor, since this UAV doesn't use IR stabilization.
1) The Nitro Predator doesn't come with landing gear. I bought an aluminum main gear (something like this would probably do), and used the front gear from Nitro's aileron-enabled Predator model. Something like this would work, and you could make it steerable, too.
2) Because the rear-mounted motor doesn't get any airflow to cool it, I converted the little hatch door underneath it into an airscoop. I also drilled out some holes in the motor mount disk to allow the air to flow through. Here's a pic (click for larger version). NB: this won't be an issue if you cut off some of the tail and put in a proper motor bulkhead and an outrunner motor as described above.
3) You can see details of how I created two equipment layers in the nose, one for UAV gear, one for R/C gear, in this post.