Well, regarding 3.5, that is good to hear. I totally expect problems with new firmware on anything. Heck, my phone, motherboard in my workstation or even my smart thermostat for my heating system all experience hiccups after a firmware update and usually some months later it is patched after some real world beta testing. The big difference is, it seems in this hobby/commercial world, is that people expectl perfection every time and if something goes wrong even with a beta firmware, they lash out and bash the hardware and every developer associated with it.
As i maintained, even during my issues with procuring a unit, im okay with real issues like firmware hiccups and the like. Thats all part of beta software/firmware and development. Ive had the experience repeated many times with many different things over my years of working with open source hardware/software.
But i digress, regarding flybar helis, i understand the bonuses and the detriments. I originally chose to go FBL when i designed my aerial rig as it eliminated some mechanical complexity at the sacrifice of many years of trouble free use/testing in the field already. It took alot of work getting the system to fly correctly and without ossicilation or vibration, but in the end it just plain worked well and that was using a simple AR7210BX. I never did get the stabilisation portion of the firmware to play well with the under-slung gimbal i use, but piloting it manually using just the gyros it worked awesome.
Ill see if i can dig up a photo of the rig, it is a rather large gimbal usually used on a 1000mm+ heavy lift multi adapted to hang under the helicopter. Ive flown anything from a 5DMKIII under it to a Nikon ASPC DSLR attached to an Atomos Ninja 2 RAW field recorder (My favorite combo, gets great clean video).
Ive got a few mounting ideas in store for the unit. Ive got some carbon plate im likely using to enlarge the forward gyro platform on the Trex, ive taken some caliper measurements and it looks like i can fit the Pixhawk there using foam tape for mounting. If i have to end up using the shock mount, ill fabricate a solution to go behind the mainshaft above the boom block. Either way that should get the unit centralized on the xyz axis quite well. The GPS will get an extension cable made and will go on the horizontal stabilizer mid way back on the tail boom.
Regarding using FBL, ive personally found that the key for me has been very meticulous setup, down to half turns on the links as well as just the right dampeners and a tight, slop free build up of the head in general. I balance the blades as good as my equipment ill allow and set gear lash just right as well. Ive found FBL units, for the most part will fly no matter what, but if there is an issue in setup and its not spot on, there will be vibration evident when it comes to video.
That being said, ive found that since its a large gimbal, unless its really bad, even though its still using servos, it gets pretty good footage.
Another thing ive found is to get rid of that slow ossicilation evident when hovering because of the low hanging mass of the gimbal i run lower head gain than someone would employ for 3D flight. Using the BeastX i had no ill effects of lower gain save for more sluggish behavior, but doing camera work it was never an issue. It also handled wind well even with reduced gain.
I have no illusions that this is going to fly well out of the box, im sure there is a long hard road ahead, but im up for a good challenge and am totally willing to put some genuine effort into this and maybe turn it into a good platform. Its quite clear multirotors take center stage, but hopefully a successful use case can generate some heli love here.?