From the start of Phase 1 flight test I figured it would be useful and fun to make videos of the flights. For example, one of the items on the third (of five) test cards says to station a ground observer by the side of the runway 500 feet from the departure end whose job it is to mark the point of liftoff. This takeoff distance could then be measured and compared to the POH values. One use of this number would be to make a judgement on prop pitch, too coarse if the number is greater than book value. My chances of convincing the Spousal Unit to do this being zero, I decided to closely estimate the numbers using the standard runway markings visible in the videos. All paved, public-use runways are supposed to conform to FAA specs for dimensions and placement ot the marks, and example being the centerline stripes: each stripe is 120 feet long with the space between stripes being 80 feet.
As shown in this photo, markings at KLMO are sparse compared to many other airports. Runway 29 has only the "piano keys" at the end, the runway number, and the 1000 foot marker (two parallel stripes). These, along with the aforementioned centerline, have specs. I also checked the measurements using Google Earth. The centerline is hard to see in the pic but is quite visible in my videos.
For cameras, I have the ever-present GoPro mounted behind me looking forward, and an Insta360 X5 on the wingtip. As I'll show, the wingtip mount is easily removable and required no modification of the wingtip itself.
The wings on the RV-12, as documented previously, are made to be quickly removable (Van's claims 5 minutes) in a manner similar to gliders. The thought was, people could trailer the airplane to the airport, fly, then trailer it home avoiding having a hangar. I've never heard of anyone doing this. To facilitate this wing removal, a hand hold is built into each wingtip, providing a perfect spot for a removable camera mount.
My idea was to make a plate above and below the handhold, securely sandwiching the hole (I love to verb a noun) with camera mount attached. And yes, before you say it, this could ideally be done with a 3-d printer. My sources couldn't print with a material I'd trust for this application, however, so I ended up buying some Delrin sheets from Amazon.
The inner plate fits snugly inside the hole top and bottom with larger, outer plates on the outside. Delrin is quite stiff and strong and great for this application. I riveted the plates together since Delrin is difficult to bond. I used the tip of a large bit to make relief divots in the surface of the Delrin which contacts the aluminum to clear the protruding rivet heads.
I secured the two sandwich halves together with two 1/4-20 stainless bolts and ran a middle 1/4-20 bolt up from the bottom to attach to the standard female tripod mount on the camera. Of course, this tripod mount is nowhere near enough to secure the camera in a 120-knot wind, so I purchased a cage for the camera (Amazear metal protective case on Amazon) which has two additional female 1/4-20 holes on the side. I made the bracket shown to attach to these. Conveniently, the bottom surface of the wingtip is at a 30 degree angle to the top surface, allowing use of standard aluminum beveled washers (also from Amazon), shown in the pic.
The cage is ideal and seems very secure.
Video here.
Going forward, my flight test videos can be found at YouTube.com/@CC-Flyer. The CC in the handle stands for Carolina and Colorado.
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