I've been wanting to increase the clearance beneath my DJI F450 frame. Right now the standard clearance is about 1.75". This video shows a basic design I've been working on to increase the clearance underneath the DJI Flamewheel frame. I'm working on this with my F450, but it should also work with the F330 and F550. The total clearance is about 3.65" which is enough to get a GoPro mounted beneath the frame.
I'm planning on doing a couple of iterations of this design to make sure everything fits perfectly and is durable at the same time. The way I did this was to take a photo of my existing DJI Flamewheel arm, import it into Sketchup, and then trace the landing gear extension. It's not the prettiest design, but hopefully will get the job done.
I plan on posting the design files when I'm done so let me know if you'd like to see them. Also, I'm going to send a few sets of these out so message me and I'll see what I can do. I ask that you at least cover the cost of shipping :)