"Ok, well it seems that there is an answer for this issue. A sharp guy (Patrick Wells) on the FB group for the Pixhawk 2.1 suggested setting the RC3_MIN to 1120. I was skeptical since I had already tried setting MOT_PWM_MIN to 1120 with no success.…"

"Thanks for the opinion Mark. I can see it both ways. The convenience of being able to remove the arms or bottom plate for whatever reason sure would be nice. The new ESCs came today so I have a couple of days to figure out what I want to do. Thanks…"

"You can look into the RC_SPEED setting in arducopter. I believe this is what you are looking for."

"Did some research on the Hobbywing x-rotor 40a and it all looked good so I ordered a set of 6 from Hobbywing direct North America. Looking forward to getting them.

I have a question about connecting them. I have my current DJI ESCs input wires…"

"Hi Andrea,

Not sure why no one has comeback to help on your post.  Not sure I will be much help either as I am right in the middle of this incompatibility issue currently.  When I bought all of the parts for my F550 build, I never considered the…"

"Well, I think I am giving up on this specific issue and am going to order 6 DYS BL40a ESCs from Banggood for ~$13/ea. I am moving on for the reasons listed by multiple people in this thread. There is definitely an incompatibility issue between the…"

"Hi Fnoop. Thanks for the reply. I totally get that the Pixhawk isn't the problem here and that it does relate to the software/firmware (ardupilot in my case). I do love the Pixhawk hardware model and can't see myself switching away from it. In fact,…"

"I won't be able to try Alexey's suggestion regarding setting MOT_SPIN_MIN to a higher number until I get back Home early next week. But... I am about the point to throw in the towel on this particular DJI ESC issue. I would be less inclined to be…"

"Thanks Alexey.  I will give it a try.  I really I wished I understood the underlying problem better as too why the problem exists in the first place.  

Troy"

"Well,  I really wish Alexey's post would have fixed this issue but it did not.  I do believe his PWM numbers are correct as I tried different minimum settings below 1120 and none of them worked.  Once I set 1120, all of the motors spun after arming…"

"Thanks Alexey!  I will give this a try today and hopefully it will fix the issue.  I have not been able to accomplish any automatic flights for this very reason.  The copter flips on takeoff.

Thanks"

"Hi Justin, yep, it works aside from the issue with the motors not spinning the same RPM initially and wanting to roll over until it gets airborne.  I will have to try the MOT_SPIN_Armed, THR_MIN and the MOT_PWM.  

The only issue I had that resulted…"

"I have the same basic setup except I have the hex version DJI F550 frame, Pixhawk and the DJI E310 tuned system. I haven't heard of the incompatibility but it could explain the odd way every flight starts for mine. Right after arming, when I give it…"