"UPDATE----
Tom,
After going insane for a week, I finally got a replacement Pixhawk and swapped the old one, loaded up the settings from the old one, and first and every shot I got Arming and even got a few flights in today.
I was impressed with how…"

"Thanks Andy, I will letcha know how it works out."

"Thanks for posting those setting Tom, I'm going to run a compare tonight. I had to take a little break from it as I am getting a little frustrated. It seems the RC out is just unpredictable. The only parameter that seems to affect it is RC3_MIN. 
I…"

"Thanks Tom,
I did try Mot_Spin off setting too. When connected to MP, it shows Armed state fine, its just the Motors that do not fire up, they remain blinking.
The tough part about this is that it is not consistent. For example, it seems like I can…"

"I do have them set to spin when Armed. My issue has something to do with the Safety switch not enabling the ESC. 
I made absolutely no changes, and today I go in to Arm and I hear nothing from the ESC upon arming.
Starting to thing something is…"

"I used the Failsafe screen to view. I'm wondering if that delta between the two values is based on some multiplier in the PX4 settings.

Ray"

"Tom,

I went out today and I noticed something different and sure enough, everything seems fine. When I push the safety arm button, the Castles began to chirp (Three Constant beeps), I armed and motors fire flawlessly. Every time.
Even though I am…"

"Tom,
Thanks a bunch for your reply. Your link is very helpful. I went an check on the failsafe screen and it seems like the Servo/Motor Out is higher than the RC In. In my case I have my taranis at 1070 for the Min. and 1895 for the Max. When I arm…"

"bump....I was wondering the same thing. Did you ever buy the Arris M680?"