Well I didn’t wait for DJI to finish my customer service order to finish their process and purchased a new motor and ESC. The PixHawk open source project has turned out to be ultimately successful, but a very fragmented and frustrating path since the documentation is weak and scattered across several web pages. It actually does not help that the PixHawk has two separate competing branches. I think it would actually be beneficial if both branches worked together to produce a reliable and bug free platform from which to program the PixHawk autopilot.
Instead we have two very buggy and unreliable software paths, called flight stacks, that are necessary in order to properly program the PixHawk hardware. WARNING going the open source route is plagued with numerous updates that may, or may not, be steps forward. This is especially true since the two sides are competing for additional features instead of competing for reliability and robustness.
Well that being said, my first flight using the PixHawk and QGoundControl default settings using the DJI 350 model as a starting point was successful. The default settings use very conservative low values for the PID feedback settings and this shows in the video. The aircraft controls were very sluggish and slow to respond from error input such as the effects from strong wind gusts. Obviously more tuning is in order.
One of the things that I noticed with the PixHawk’s GPS is that it is much more sensitive. While I could get a GPS lock with my DJI Phantom placed near a window or patio door the PixHawk can lock on to five satellites a full twenty feet from any window inside of my apartment! I’m very impressed! Also note that while I had some trouble reliably controlling the aircraft, due to weak default PID input values, the aircraft still acted in a positive manner, even at the end of the video when the battery became detached and ultimately unplugged it still landed upright and unscathed! The first flight for the PixHawk were decidedly superior to my first flights using the Phantom autopilot, which all ended up with uncontrollable crashes and in the destruction of several propellers:-(
Here is an image showing My new creation with the DJI Phantom. Note the huge 10AH 6S battery that obviously needs a more robust mount than velcro and a single bungee strap to secure can provide.
I’m actually thinking that I will use this prototypes acquired knowledge into making a hex-copter, since the extra weight of the battery eats up most of the extra power supplied by the motor-ESC combination. It was obvious from this first flight test that the hover power was actually at about 50% when adding additional weight of a camera/gimbal system will probably overload this setup, especially when used with this huge 10AH battery. DJI is actually sending me a new ESC, I’m still not sure if they are sending me a new motor and props, but I will find out Monday when the shipment should arrive.
Oh ya, I also have been spending a lot of time learning how to use and program my new radio transmitter and receiver, the FrSky Taranis Plus sixteen channel transmitter and the X8R SBUS receiver. Also an open source steep learning curve quagmire of fragmented sources of software ind information. Ultimately I am very happy with my choice, just be forewarned a lot of time surfing the web for weak and fragmented documentation should be expected.
Sounds like to me another trip to Home depot…