Hexacopter motor issue

[RD18]

Hello all! Hope your day is going well.
I'm having an issue with my new hexacopter build and hope someone can help me resolve it.

About 6 months ago I built a quadcopter that worked with absolutely no problems at all. But a few weeks ago i decided a hexacopter would be a lot cooler to own so i bought the frame (s550) and bought 2 extra motors and 2 extra ESC's, and I took all the electronics off the quadcopter ready for the hexacopter. I began too attach the parts to the frame and now I have reached the point of testing the hex but have now hit a brick wall (metaphorically). The 4 motors off the quadcopter are working perfectly, when i arm the hex they start up no problem. but the 2 new esc's and motors are not so dandy. They don't start unless i lift the throttle to nearly a quarter of the way. When i test them seperatly the new motors start at 18% and the old motors start at 4% which is quite the difference.

I thought I did a bad esc calibration so I calibrated it again and still the same problem. I re calibrated all the other motors as well but still have the same problem.

The new esc's (Hobbypower 30A) and motors are identical to the old ones except for the motor colours. the old motors are black the new motors are silver but are exactly the same motor (marspower MX2212 - 920KV). I'm using an APM 2.5. Is there a way of increasing the minimum level for the motors in mission planner? Or am I doing something wrong. I've now re calibrated the ESC's about 3 times and still no luck. Can anyone help?

 

[Craftydan]

Hey RD18, Welcome to the Forum!

As far as the "on" throttle, the problem isn't in the motors -- they just do what the ESCs tell them to, so we can eliminate them.

The issue here could either be the ESCs or the control board . . . so swap a pair of ESC connections between a "good" and "bad" ESC and see how things change (props off, please). If the "good" ESC starts misbehaving, it's in the control board. If it stays with the "Bad" ESC, it's an issue with that ESC.

As for fixing it . . . if it's in the board, you're going to have to look in detail at the board's setup of each output port. I've not played with APM so in that, I can't help.

If it's in the ESC, yeah, it's a calibration issue. you can re-attempt the calibration one-more-time. If you're using a calibration routine on the APM, then think about unplugging two of the "good" ESCs (let them sit out this cal) and plug the bad ones into those ports. when done, their calibration *should* match the cal on the other two.

If you're up for it, you could flash it to SimonK (tgy.hex), but you'll have to do it the hard way. If your soldering chops aren't up to tiny wires on tiny pads, not a great option. BLHeli is a better ROM, IMO, but it's not supported by this ESC.