So last night I try out my Iris for a bit, to see if the new firmware and accel calibration worked. (BTW, the new firmware seems good, and the accel calibration has improved it’s idle position hold, but its still not 100%. I still need to trim it slightly).
All of the sudden in the middle of me showing the Iris off to my neighbor, one of the props came flying off - the Iris was about 6 feet off the concrete, and just hovering, when it fell, fortunately, and so there wasn’t any damage, just a few more nicks and bruises.
I quickly put the prop back on and checked the others and got it back up in the air, and all was well again.
Anyways, this has me now begging to ask the question - dare I put blue locktite on my prop nuts??
Apparently I have to! Jeez, I would think they would stay tight. I guess a few flights/vibrations had worked that one loose. There’s no EASY way to tigthen those nuts good - the motor just slips from my fingers and almost cuts my hand when I try with even a slight bit of force… POOR MOTOR DESIGN IMHO!!
DJI has self-tightening props. How can I get some like that for the Iris?
Blue locktite IS removable, so I think I’ll use it. (Red isn’t FYI)
Be very careful with Loctite: It attacks and damages plastic parts. So you might end up making things worse.
I’m also a bit suspicious of the propeller mount on the IRIS and check my props before every flight.
Just to make sure. Did you assemble the props like this:
Plastic insert from propeller on motor mount, push it all the way down
Insert propeller on insert and push it all the way down
Insert the teethed washer onto the propeller with the teeth down (Should fit perfectly in this little nudge inside the top of the prop).
Add the screw and tighten it.
From what I can tell the teethed washer appears to be a potential failure point. It eats into the plastic of the props, potentially damaging it and the teeth wear off after a while. I also notice that the other 3DR multirotors use a different kind of prop mount.
Also I bought a different tool to tighten the screws. The one provided by 3DR would just start hurting my fingers.
With that I have on my to-do list to check the prop mounts for potential failure scenarios and fix them.
But before that I have to go through the other issues first. And at one point I also want to just fly.
Yes making sure your props are tight before every flight should be a mandatory check, I would suggest getting an 8mm nut driver as it is a lot better for tightening the prop nuts, the supplied one works but that doesn’t mean its the only option.
I put a bit of blue locktite on my props and help fine thru several flight and minor crashes (flip on landing). Always checked before flights.
My props need changing after being a weed wackier and I was thinking of trying nylon lock nuts. Online research shows differing opinions. It don’t care if I need to replace them every time I change props.
How do you guys hold the motor still when you tighten the prop nuts? I can’t figure out a solution that doesn’t slice my hands, other than use a towel to hold it steady.
I think I lost a teethed washer on this past flight when the prop came off, actually. I will need to see if the others have them, I don’t really recall - and if so, get another. It seems the purpose of the teeth is to prevent it from rotating along with the nut.
When I tighten, it seems like I am pushing one way with the nut/driver and the other with the motor and prop itself. The prop kind of locks into place as it tightens. Is it OK to put some of this counter pressure on the props? I’m not pushing too hard, but hard enough to get the nut really tight on there. Didn’t put locktite on - yet…
