gemfan props

[helionfire]

i bought some gemfan 9x 4.7 props for my flamewheel 450, had to drill them out to fit the motors,put them on and when i did a test flight it was pretty stable but when i put it in atti it just kinda went up and down and would not hold its height. i used a drill press to open up the holes and the props were a nice snug fit, i also tightened the prop nuts firmly so i dont think the props are slipping. could this be because i didnt balance the props?

[Stumblebee]

I use 10 inch Gem Fans on my F450. I have not had your problem. When I installed mine, instead of drilling out the props, I used a prop reamer to cut the 8mm hole. I did all four props in less than ten minutes by hand. From what you have described, I would try a few more flights and see if you are having a consistent problem or an intermittent one. I say this because I ran into the up and down thing a couple of times when the weather was unsteady and the barometric pressure was bouncing all over the place and the wind was coming from a variety of directions.

[petedee]

What gain settings are you using?

I am using the same props but with 5mm prop adapters on 2830 motors I do not need to ream the hub.

Always balance both your prop and your motors, it may be causing just the right vibration to upset your Naza.

Pete

[helionfire]

pitch 95 roll 95 yaw 120 vert 180, attitude gain 120, and actually i dont have a prop balancer, any recommendations where to get one? and im not sure how to balance the motors

[Stumblebee]

I've been running those same numbers since July. No problems so far.

[TioDave]

I ran some 8" gem fans on my f450, but I had to rheem the hub down to 2mm thick. I heard the larger ones fit better. I tried some graupner 9" e props. The 9" was to big with 4s. Now I'm running the APC 8" SF with great results. They needed to be rheemed and balanced, but I have the highest gain I have run with so far. It might just be the best balance from practice.

[Dumb Thumbs]

I've had GemFan reinforced 10x4.5 props fail on me in flight three times to date. Just today I was out flying with a small onboard vid camera. No props broke, but watching the vids later I heard the props balking when moving the quad around at a moderate clip or when the wind kicked up. I can only guess that the blades were flexing, and given time would break.
I'm not saying GemFan props are bad props, Just that my Quad (NextLevel 650 with 3 cell 5,000mAh batt and a camera) might over stress the GemFan's.
Got myself some Graupner's on the way and I'll see what happens.

[Stumblebee]

In my limited experience, this is the first time I have heard of a Gem Fans failure, much less three. I can't say I know much about NextLevel machines outside of their reputation for being very well made, powerful aircraft.