Aircraft Type: CS8, MT3515-15 400kv, New MK Quadro 2xl ESC and New FC 2.5 Gimbal Type: AV200 Camera/Lens Being Flown: MK Stack: FC 2.5/Firmware 2.02b Navi2.0/Firmware2.02a, GPS Flight Radio/Recv Type:MX20/MX24 Symptoms: After upgrading to a Quadro2xl board and FC 2.5, # 5 ESC stutters or binds on start 50% of the time. I have tried different motors on this boom and the problem persists. Motor tests without props were fine and I didn't see any errors. Not sure where to go from here. Video:
In my experience this is called a commutation failure -- the motor fails to spin up as you're observing, or even can run in reverse briefly. Normally, the motor "comes to its senses," and starts to spin the correct way, but I've not seen such a persistent failure as your video shows. As a quick test, swap over the motor wires on the PDB for another odd numbered motor, and see if the problem moves to the new motor. If it does, then the issue is with the Quadro board. If it stays with motor #5, then the problem is with the motor. This will at least allow you to figure out how best to proceed. Andy.
Thank you for the input. I tried motor number 3 on PDB address 5 and it moved over to that motor so it must be a board issue. I've emailed Mikrokopter.de as well for input. Someone on the Mikrokopter forum posted: "In the various tests with different motors on the BL-CTRL 3.0 I've found it at einzelenen engines can occur when starting the engine to start-up difficulties. The motor starts up immediately, but stutters shortly. To avoid such problems in which one changes the StartPWM value. For the MN3510-15 I increased the value of 2 to 4." I'll give this suggestion a try when I get back to my studio....through mk tools I presume? David.
I have noticed the same phenomenon with my system, and if I give the motors a little bit of gas they all do fine. I am running with default values everywhere, and it just seems like maybe an idle value or something is set a little low. There are no errors reported anywhere. But it is a little disconcerting!
I'm now getting a I2C error and all eight BL's have the red green LED's on. Would one bad controller cause them all to fail?
That happened to me when I had a BL go bad. It evidentually stopped working all together. Yes one bad BL can give you I2C errors. The other controllers are not failing, its just how MK tells you its failing. You can get a new BL and solder it in if you have experience and confidence with soldering. Otherwise the next best thing to do do is to send it to Quadrocopter and they can do the repair.
Dave, have you seen this with the Double Quadro 2XL? Do all your motors start consistently at low idle?
I'm using a Quadro 2xl board which makes swapping out one BL Impossible (at least for me). It's a new board and the problems were there from the onset so I guess the next step is to call Quadrocopter and see if they can do a repair or replace it.
Steve: I think your finding the same issue as David was -- if the starting pulse width is too short, then the motor has the commutation failure, so goosing the throttle extends the pulse width and, in effect, slaps the motor across the face and tells it to spin up and fly right. @David: I'm not quite sure where one goes to change the StartPWM value on those new boards. I'll see if I can find out -- but I don't have the boards myself so you mind find the answer before I do -- if so, would you be kind enough to post the answer, please? Andy.
I will try the StartPWM suggestion and see if that helps. You hold down CTRL and click settings, right?
Andy Here's the menu. To access it you need to press control on the keyboard while opening the settings in MK tools.
I gave that a shot this morning and it only seemed to make things worse. A few of the other motors became a tad sluggish and no improvement on the first one. It was right after that I lost contact with the BL's and got the I2C error.
Thanks. I wasn't sure what they'd changed on the 3.0 board set -- looks like it's the same as 2.0 at least in MK Tool. Thanks Andy.
That's odd. So you changed the setting for Motor #5 and one of the other motors changed its behavior? That's definitely something for Holger Buss to know about. Andy.
For address did you hit all, select one at at time or just select #5? IF you want to change a certain BL's parameters you need to select only that BL so for motor #5 you need to select 5 under the address column.