To commemorate the GREAT flying code of 2.0.19, I put my CNC machine to work to cut me a new frame. As always, I spent a few hours making sure everything looks good, and that it goes together nicely. To do that, I used Solidworks! I spend quite a few hours designing the frame (as you can see not entirely my design), modifying and making changes. When I had it all the way I wanted, I then created toolpaths for my CNC machine, and I cut the whole thing out of G10 (Garolite) about.06inches thick. The whole frame came in at about 320 grams (just the frame with glue off course), which is not bad. A little on the heavy side, but for the strength I get out of G10, I am willing to sacrifice!
You can see the computer screen of the model above.
Yes, I even went as far as modeling the motors, and the props....had to, to see how it would look!After some hours of cutting (had to use a very small bit, at about 20 IPM for the speed) this is what it looks like now:
And here are a few more shots and close-ups of the oilpan and Xbees, GPS, Etc....
Some details:
-As you can see on the legs, there is a 1.2Ghz TX, and in between the legs is a CCD Killer camera, for FPV (using the Fat Shark Goggles). Battery on the other side of the legs runs the FPV system, and it is a small 3S LiPo. Main battery as you can see, is below the legs. The next step, and currently in solidworks, is the Camera Gimbal, which will sit below the copter, in a shock-mount with a titl/roll servo setup for video. That is next. Receiver is a Frsky 2.4Ghx two-way telemetry unit, and I am using a modified Futaba 9c for my radio.
-Props are 11x4.7 tractor/pusher pairs from APC. I was thinking of using 12x3.8, but I think that will over-prop the motors. The motors are Cobra outrunners (new on the scene, and I wanted to give them a try). They are 2217 at 960KV. VERY well made, and I can really see the difference in the way they run, when compared to $14 turnigy from HK. These were about $40/per, which is not all the bad. They do get a little warm when I land and check them, since again, I think an 11in prop is a tad too big...but I get about 1000g lift/per motor...so I can probably lift a stray cat out of the neighborhood! LOL! One thing though, the mounts where a little big, so again, I cut new mounts on my CNC out of G10, and that solved that! ESC's are turnigy Plush, 30A.
-The frame is a monster...it has 27inch span between motors...and I designed it around the ACM, with a special cage in the middle, that protects the electronics (again cut the mounts out of G10). You can probably see this (I used blue G10) in the pictures above. The GPS as well, is protected, encased on the upper part, so even if I flip it, no electronics will come in contact with the ground. I painted it using regular automotive spray paints, after I gave some of the G10 parts a light sanding, so it sticks better.
-I get about 6 minutes + on a 3000mAh LiPo 3S. I will probably go to a 4S, or run a couple in parallel in the future...we shall see, depending on how I use this thing. I also have a strip of LED's under the arms, with a brushed ESC to control them. I inserted a bit of code in the tree, that allows me to get the LED's to pulsate when the motors are NOT armed, and steady when it gets armed. As you can also see, there are holes on the tips of each ARM, for more LED's, and I will soon have a surprise for those! Videos are coming, so watch my blog! :-)
Now to the code: VERY VERY STABLE with ACM 2.0.19! THANK YOU Jason and The Team! You guys rock!
I had to lower the PID's considerably from the defaults (except for yaw), and my Yaw is ROCK steady, and so is the ship! I used to get severe oscillations with the Pirate code on descent, and so far, with this one, I can drop it down from above like a brick, and it stays rock steady!! PID's for Roll/Pitch: .2/.05/.1 and for yaw .8/.05/.1 (A bit higher than the defaults on Yaw).
I have not played much with Altitude hold or GPS navigation yet, but that is next. The ship does have a sonar, so that should be fun.
One of the many cool things I like about the frame, is that all the cables and electronics can get easily placed "within" the frame...this makes for a very safe and very neat installation! For example, the ESC's between the arms, and all the wiring with a power-ring I created, in the lower part. I cut the power ring out of Copper clad G10 (double sided).
Well, shoot me questions if ya have them....