Alex Postowoi

I don't know what weight you are planning to fly, but here's an approach. You'll need a machinist to build and source the mild steel for this. Let's say like me, 28 pounds on the sled is/was a normative comfortable weight to fly around the neighbourhood to build ones flight skills. For me that weight consisted of 2 one inch steel plates, about 12x5 inches, duct taped together over a piece of steel tapped for a 3/8-16 accepting insert to mount the thing to the sled's base plate adapter. Get holes drilled out up top to accept a GoPro (or whatever you're going to mount). And the with "GoPro" and lens converter of your focal lengthening choice - go run up some stairs. Just kidding about the running part. Directors will torture you with endless takes of something far heavier and worse than that. 😉 Also be sure to consider the actual motion picture camera lens height heights and positions.