Motor spinning at zero throttle

Hi, I am newbie. I am using a pixhawk 2.4.8 as controller for my quadcopter. Iam using ESCs of different companies,(3 of them are same), but of same specification. I have calibrated all ESCs. But when I start up in normal mode, motor connected to the dissimilar ESC spins up at zero throttle. But during calibration phase all motors were starting up together. Pls help.

A: I would suggest using esc’s of the same brand and firmware. Also, have your tried using the all at once calibration method instead of the esc calibration button? Also, setting the RX and tx to zero in the calibration menu forwards tx values to esc’s, you could also try setting the min and Max connected directly to your reciever. You’ll have to disable ppm and disconnect from FC before doing.

i have done the all at once calibration method. after calibration, all motors starts to spin in same throttle level. but after restarting pixhawk in normal mode the same problem persists.

Also, I just had an issue purchasing 4 brand new esc’s…all the motors would fire up and lift the quad off the ground but then it would slowly descend. The quad was actually reacting to a bad esc. Because it couldn’t maintain lift on on arm, it would lower the throttle of the rest of them just to maintain not falling to the ground. Moral of the story…just because an esc might seem ok, doesn’t mean it is. Took me a few days to finally figure it out, data flash logs weren’t clear on the issue