I got into multirotors to do aerial photography, specifically to shoot bike races. After a lot of research I chose the FPVManuals tricopter, largely because tricopters were said to fly more gracefully. Unfortunately, it proved to be too delicate for a crash prone noob, so I started looking into designing my own VTail (which is the totally logical noob solution here).
After many iterations (and the advent of brushless gimbals) I ended up here. You can tell by the nice lighting and background that I was super excited to build this puppy up.
That’s a Beholder Lite up front, with arms taken from a Flip FPV, bobbins from Lumenier and rear motor mounts from Hobby King. Sadly it was a terrible design – the rear booms would slip ’til the props hit each other, and the battery blocks the rear props’ thrust. Most importantly, the whole thing was an oxymoron. I chose a VTail layout because it flew more gracefully, but the gimbal levels out the video so you can’t tell anyway. All I had was a heavy, badly designed, inefficient flyer.
So I made it a quad.
I had basically reverse engineered a QAV 540g, with much failure and expense along the way. As you can see the Beholder is now firewall mounted.
I tried a few positions for the fpv cam, not wanting to put it up above for fear it'd be too vulnerable in a crash. I hot glued to the dirty section, put it on studs beneath the clean section, but no matter where I put it I got so much jello in the flight video it was difficult to concentrate on flying. I finally caved and put it up top and that solved everything. I found it really surprising that the camera mounted the same way above and below the clean section yielded such different results. I guess it has to be the prop wash buffeting the camera. Long story short, with the camera up top, it was now REALLY a copy of the QAV 540g.
This thing worked great, first on KK2 then Naze32. One thing I noticed, however, was that it was a tad sluggish to yaw. I made it with a square motor layout, but it seemed to me that if I moved the motors closer fore/aft, then the camera/gimbal and battery could both move closer to the CG, reducing the yaw moment. I jammed the battery up against the FC (which has to be at the CG), and moved the camera and gimbal back to balance. I also decided to move the motors out a touch to get the prop wash away from the gimbal.
The arms are barely rendered ’cause I’m still using those Flip FPV arms and landing gear. I put two vtx’s on it so a second operator can view the GoPro feed and control camera tilt. Here it is with Lumenier 4006’s and 12″ props.
I couldn’t get that last bit of jello out with that setup so I went back to Sunnysky 2216’s and APC 10×5.5 props. At just 1660g with a 3300 4s it’s super light for a quad of its class.
Two years after I got into multirotors I finally shot that bike race. I really love how this thing flies, it just goes where I think, which is great when I’m tracking racers while flying sideways through trees, totally confident that it's going where I want while I focus on the shot.
Side note: After flying for half a year I foolishly thought I was good enough to shoot a race. At the time I was flying that Flip FPV, and the day before the race I took it out for a shakedown and promptly spiked it into the ground and split the LiPo – check out the smoke at the end of the video. In hindsight I’m so glad I didn’t shoot that race as I clearly wasn’t ready to fly near people!