"I'm having a peculiar issue with our now-revived Matrix quad copter.
I set the log bitmask to 894 on the pixhawk, to get Default + RCIN

However, our log isn't recording. So I deleted all the logs on the pixhawk through terminal, and flew for 5…"

"Hi Mike. We actually replaced the #1 motor, due to it not keeping up sync, and.....

We found few wires broken, and the entire center support shaft was destroyed. It must have gotten an hairline crack during one of our hard landing on previous…"

"I'd like to follow up on this:
The hexacopter is now flying amazing. 
Our Accel Z was between +3 to -20! no wonder why it flew like crap. We had trouble with cold weather making the vibration absorption foam here, so we bought an AVdome from…"

"copter is not flying okay in alt-hold and loiter. I will check vibration levels first, as the log didn't record it. "

"Thanks much, there was some cross wind, ~5-8mph, which the two front motors, were facing.
I will perform the sync test as its the only explanation on what could've happened.

Thanks for your insight."

"We will do this test, with the quad tied down to the table, with props on upside down, one position over, to reproduce the results with the current esc/motor. to see if we can get it to lose sync while switching through all the modes, and…"

"Hi Richard, the prop is the bolt on type, with two screws and a retaining plate. The prop didn't move at all.I visibly saw the #1 motor stop turning entirely... :/

We have a spare pixhawk to throw on there, but now we are back to square one.... We…"

"Thank you for your reply, It does seem like a sync issue. I just cannot find another point of failure, as I have followed the WIKI to a letter, and followed all the pre-flight and setup perfectly.We are quiet bummed about this crash. "

"Hi Michael, Thanks for your insight.Could you explain to me where you see the #1 motor failing? I fail to see where the motor one was starting to fail, because when I look on the log, on RCOUT on CH1, the 100% demand was right when I switched to…"

"Hello Randy and developers.We experienced a catastrophic failure on our geo-surveying Turbo Ace Matrix quadcopter. 

It was our first auto-pilot mission with this aircraft. 
I will describe the all the steps we took.1. We powered up the aircraft,…"

"I will. just to make sure, I shouldn't need to do the ridiculous 30 degree nose up level calibration again right? I should be able to just level with a reflex dialed in...."

"I seriously would like to buy you many beers. Thank you!!!! what you have said made so much more sense than the wiki...

So let me try to figure out what I need to do this week.
1. re-fly the rvjet with the payload to figure out how much trim is…"