Designed to carry a lot of equipment yet still be completely portable, the Porta-Quad is for exploratory missions–the one pictured has a full size APM, GPS, 3DR radio, and FPV, and weighs about 650 grams (frame weight about 200 grams). Designed for 6″ props and 1800KV-2300KV motors, the frame is made from tough G10, and the two back legs fold for portability. When folded, it fits into the inexpensive Turnigy aluminum radio case (230x270mm) without the need to take off the propellors. It has a square 8″ motor-to-motor spacing, and quite crash-proof.
Perfect for scouting out what’s over the next hill.
Background: Mini quads are great fun. I started with the excellent Spanky, then started playing around with my own designs. I am an engineer by trade, and have always enjoyed the design process. We go camping a lot, so I needed a way to put my quads in a packed car with kids, (stuff gets moved around a lot en route). My first 8″ prop quads could fit into an inexpensive aluminium case from Hobbyking, but required time-consuming prop removal and assembly each time flying. The nice thing about the Spanky was that with 5″ props it fit into the larger case with the propellers on.
But alas, I like the autonomous features of APM, using a 3DR radio (and Droidplanner on a Nexus tablet), and trying to build a 5″ prop quad with all the stuff just didn’t fly. And of course, every quad I build has to have FPV. Just not enough thrust. I knew I had to go to 6″ props. But how to fit into a small case?
I looked at the folding designs out there, but none of them really grabbed me for ease of deployment, or didn’t have the dirty/clean vibration isolation which I consider essential, or seemed too fragile. I really need something bombproof (I tend to crash a lot). I know the common wisdom is that quads need “replaceable arms”, but I’ve had some pretty fierce crashes from high up with one-piece 3mm G10 frames, and nothing’s come close to causing any structural damage to my frames. So I decided to minimise the complexity by only having two folding legs which has the added bonus of even faster deployment (and still, of course, fits into a small aluminum transmitter case).
Prior to this design I was building a lot of 5″ propellor mini-quads, and went through a learning curve trying many different motor/esc combinations and thrust-to-weight ratios in attempts to lift all the stuff I like to put on my mini-quads (i.e. full-size APM or Pixhawk, 3DR radio, OSD and FPV Tx and board cam, separate HD cam, etc.), and finally came to the conclusion that 5″ props and 2300KV motors just don’t work well with anything over 550 grams. My current mini-quads generally weigh in at about 650 grams (sans battery).
The “porta-quad” in the AutonomousTest video has 6045 propellors, but that’s just because I ran out of 6030’s when I tuned it. I find that 6030’s with Cobra 1960KV motors (and 12A Escs) is the smoothest way to go–and with the added benefit of requiring minimal tuning (actually, none) with OP Revos, CC3Ds, and APMs (whereas the 6045’s require careful fine tuning of the PIDs).
PARTS LIST:
Frame Hardware: Dirty/Clean section with folding arms:
4: rubber bumpers: 10mmOD, 10mm Height, M3 thread (same as Blackout red ones)
4: M3x8 socket hex (HK)
6: M3 locknuts (HK)
4: M3x12 socket hex (HK)
2: M3 Wingnuts (Drone Matters)
8: #3 washers (8mm OD) (HK)
Frame Hardware: Top frame connection:
4: 18mm brass standoffs (ebay)
4: 5.6mmx12 M3 nylon spacer with threaded section (6mm long hex section)
2: 5.6mmx36 M3 nylon spacer with threaded section (30mm long hex section)
2: M3x8 nylon screw
6: M3 nylon hexnuts
Recommended Equipment:
APM or Pixhawk
FrSky RX
Cobra 2204 1960KV motors (also flies well with 2300KV motors)
12A Escs (or Afro Slim 20A)
6030 or 6045 props.
Vibration Mounting foam for FC.
Because of the small space to fit all this, shielding (copper tape) and noise reducers (ferrite rings) also recommended for electronics.
Optional:
3DR radio—with 900MHz 1/2 Wave 2dBi Antenna w/SMA Male Connector (ReadyMade#ANT-916-CW-HWR-SMA). Long range here: http://rfdesign.com.au/index.php/rfd900
FPV equipment: (good source: http://www.surveilzone.com)—very good addition to FPV system:LC Power Filter (ReadyMade# LETSFPV-LCFILTER)
GPS foldable stand (GPS/compass needs to be set higher to prevent interference)
