Clockwise props unscrewing after hitting grass or object

I have a new IRIS.

I’ve been having a few issues with what seems to be the propellers coming unscrewed.

First, YES! I have checked and rechecked many times to make sure that the props are tight.

This is what seems to be happening:

In my two flight attempts so far, I have had one of the Clockwise props come unscrewed, after contacting something during landing.

In the first case I was landing under control in LTR and I believe that the prop came into contact with a tall blade of grass or something and the prop unscrewed and the IRIS flipped into the ground.

In the second case I was going to land in LTR or ATL near the original launch point when the copter lost control and started flying as though it was automated (no automated missions were set), the copter flew straight into a post behind me and unscrewed the propeller again and dove into the dirt.

So, I have two issues here that I need to resolve:

  1. when the clockwise propellers are impeded the motor seems to unscrew them from the bolt.
  2. why did I lose control of the copter before I lost the prop in the second case?

I make two assumptions here:

  1. that the loss of control was pilot error, setup or maybe GPS related.
  2. I believe that I have the propellers attached correctly according to the literature.

Can someone please help me determine:
a) if the props are attached correctly? I am attaching the props to the motor in the following sequence:
Small plastic spacer washer, prop, lock washer, nut on top, tighten, double check.
b) how to tell what happened to cause loss of control in the second case?

If I am attaching the props correctly then I think I may start using a nylon lock nut in the future to keep the prop from coming off when landing in stiff grass.

Thank you for an awesome product!

From your description, your props are installed correctly: insert + prop + washer + nut. It sounds like you need to tighten the props a bit more. I’ve flown my Iris five or six times with no props loosening, even after a couple of bumpy landings. When I tighten the props, the nuts snug down until the prop shaft appears just above the top of the nut.

You could always add a little removable (Blue) locktite. Personally I would like to see left hand threaded prop mounts like other Multis. are there any commercially available that fit the motors?

DJI Fixed this with self tightening props.

I found the props really hard to get on, wasn’t sure how far down they should go since this is my first UAV.

I got the nuts to just catch and then used an 8mm socket driver (screw driver type) to snug it down until it was flush. Can’t say I have it right because I have not been in the air yet because of crappy weather.

Thanks Guys,
I’ll try tightening even more plus a little blue loctite.

As ShockWaveRider said, the real issue here is that the clockwise props are using the wrong handed thread.

Anyways, I really appreciate the feedback. At least I know I’m not the only one. SWR, I’ll look around for some left handed arbors for the motors and let you know if I find any.

[quote=“Oregonh2o”]I’ll look around for some left handed arbors for the motors and let you know if I find any.

There are a couple out there, but there are no dimensions published for the mounting holes on the motors. Perhaps you can measure them, tell us here, and ask around. The ones I have seen are for DJI 22xx and the Blade 350qx. Not much about for the 2830 motors. In addition a longer shaft on the adapters would allow installation of an additional lock nut or a Nylock. Sometimes I cannot understand why folk put so much effort into a great product and omit the smallest details that can have a catastrophic impact in the case of a crash because of the props. Also omitting Nav Lights I think is also a minor omission.

I love the concept of the IRIS, but the Short Legs, and no option to order longer ones, The Props and Mounts, general lack of mechanical spares “currently” available, and of course my real pet peeve that we are forced to use their radio. I think this leaves the door open for 3rd party providers to fill the holes. Perhaps that is the idea.

Here is a spec sheet for the mounting holes for the AC2830 motors.
Now we just need to have some made or find some pre-made.
Steve … /A2830.pdf

I think these quick release self locking adapters are a really good idea: