Iris pitching forward with GoPro on nose mount

Originally posted in DIY drones - I didn’t realize this is the correct place for official IRIS support.

I need a bit of help with an Iris problem. I’m new to the Pixhawk, but not new to R/C and drones in general. I was testing waypoints for the first time yesterday, with a short mission over a soccer field. I was piloting with the TX, while my wife was operating droid planner on my Samsung Note 10.1 2014.
After two successful runs in auto, and enough flying in stabilize and loiter to run the battery down, I switched to a fully charged pack. I also mounted my GoPro in it’s waterproof case on the front of the copter. I took off and flew around in stabilize for a minute or two with no issues.
I switched to auto and the Iris few fine. Upon hitting the last waypoint, the iris switched over to loiter mode. I wasn’t getting very much in terms of response from the sticks (which I expect in loiter), so I switched to stabilize.
The Iris then pitched violently nose down. I switched out of stabilize, and my wife i believe hit return to home. Droid Planner chose that moment to crash, so I attempted to switch things back to stabilize, but the drone again pitched violently nose down. Back to loiter and try to get it back. We weren’t making much headway, and at this point the Iris was drifting close to trees and houses.
With the drone not responding to my directional commands, I made the hard choice and switched to stabilize while chopping the throttle. The pitched nose forward then dropped, landing nose down on the GoPro.
Damage was relatively minimal. the GoPro horn cracked. The GoPro itself shut down (shock to the battery?) So I lost the last 10 or so of video. I did capture the violent pitching though. The battery popped out and pulled out the Status LED window, and It looks like the telemetry radio screw popped through its mount. Arms, Props, etc appear fine, though I’m going to remove the body shell to verify everything is ok. I did hover it one more time after the crash to verify no major damage.
I tried to download the logs last night, and It doesn’t look like I’m getting the full log file for this flight. In mission planner, If I download all logs, I get a 0 length file. If I download just this log (Log 8) I get an error about renaming the file, and end up with one of two file sizes. I’ve attached the longer file set. It looks like the file is truncated, but there is data there showing the pitches.
I can see desired pitch changing wildly, but I’m not sure why this is happening. Can someone take a look and let me know where I’ve screwed up?
I initially thought my mistake was not re-calibrating when I added the GoPro to the nose, but 3DR’s video makes no mention of this - plus my take off and flying in stabilize mode showed no pitch issues. Only after I flew the way points did the problem sneak in.
Thanks for reading - hope I’ve given enough info!


I think you should change parameters for IRIS with GoPro front mount.

How to do it, is in this video (except, you don’t have gimbal, but front mount):

Just FYI I believe IRIS will be still pitching forward, because waterproof case is to heavy. Solution is black GoPro frame or autotune option.

BR, Tomas

Tomas - I saw the gimbal video. I actually based my setup on this video:

which shows 3DR using the waterproof housing. Just like the video, I kept the camera pitched way back against the nose of the IRIS.

The ironic thing about all this is that I have a gimbal ready to go - I just wanted to test the GoPro on the front mount first. After being in a situation where I had little to no control of the craft, I’m a bit nervous to put the delicate gimbal and naked Gopro on it - at least until I get a good answer for why the IRIS would be controllable early in the flight, and change so radically only a few minutes later.

I haven’t seen the video before, lucky for me.

I am pretty confident, you must change IRIS parameters in Mission or APM planner, as shown in video with gimbal setup. There is even prepared profil IRIS with front mount.

GoPro in waterproof mount weights around 160g, which is basically 10% of IRIS weight. That will certainly move IRIS’s center of gravity. But be careful with first flight. I think IRIS front mount profile is not for waterproof case, but only for black frame. Therefore IRIS will be still pitching forward and you will have to compensate.

As next step, I would recommend autotune.

I had a similar problem with IRIS and I was using the front GoPro params…Broke a prop too.
No response from 3DR to my post or email either.
See viewtopic.php?f=25&t=8907

I had this issue, mainly in RTL mode but the same. Make sure to load the right settings for having that much weight that far forward. I wish they would put a warning in the manual for this. I flew with the frame + loaded parameters from APM for Iris + Front GoPro