Twice earlier this winter, I have had a go wit my quadcopter,and both times I went home with a damaged copter due to a blade snapping in mid-ait during easy flying or hover. Since the temperatures were arounbf -10 degrees C, I thought this could have been caused by the plastic in the propeller becoming brittle by the low temp, so postponed further flying.
Today I went for a flight again, and the hover in stabilize was quite good, suddenly a blade just snapped and the copter fell to earth. This time the temp was around 0 degrees C, so I dont think the temperature could have any influence. These were all cheap ebay propellers so I guess that the quality is just too bad, but could anyone advice some better props? I need the bigger 12x4.5 ones as I have the motors with larger kv.
Anyhow it puzzles me that the props are so bad that they are really not working, they were all balanced as well, anyone with a good explanation for this?
Geir
Replies
Had my first prop break in flight yesterday after many, many flights, quad was about 5m high but I managed to land (just) without damage. Using the cheapish 10x4.5 props from Goodluckbuy. Temperature was about 25C. Quad weighs 1.3kg. Must be the props themselves, presumably made from cheaper plastic, as I wasn't doing any sort of aggressive manoeuvre.
Was the reverse pitch one too (always is!), think APC are a better bet. Have broken 3 expensive Gaui props too but those were either in a flip or striking something.
Don't mind if a prop breaks in that situation but to have one break in flight is really bad.
If your quad is heavier or you are doing aggressive manevaurs, you could be stressing those blades to ultimate failure. it's a known issue with those EPP, chinese, etc blades. They tend to work best with lighter quads. I never had one fail in flight, but you could see them bend under load and have "stress" marks.
Go with the 11x4.7 SF APC or 12x3.8 SF APC props. Much better quality and strength. They even can sometimes survives crashes, better balancing as well. The 12x3.8s have much more area than the 12x4.5s, so you may need to re-tune your quad after the switch.