Beefed up prop guard for 5 inch props

Designed for multi-rotors that use 5 inch props (or smaller). [250mm size]

I beefed up the prop guards a little bit. I print them in PETG [my new favorite filament type!] and they seem to work quite well.

I don't normally use prop guards, but it helps when I'm giving lessons to friends who are just learning to fly, or if I'm flying in a place with a lot of obstacles (trees etc.).

PETG seems to make these very flexible but sturdy enough; and the "beefing up" I did adds only a few grams t