Hi Scott: That's an interesting issue. Not one I've seen before. (Doesn't that make you feel good?) I infer that not all of the motors are speeding up as you say it wants to lean forward as you increase the throttle. I would take the props off and do some bench testing while you have the C8 hooked up to MK Tool. When you first start up MK Tool and have established a connection, verify that there are no error conditions shown in the central window and below that, all the systems colored squares are green. Basic confirmation: with the motors running, give it some gas, and throttle back (as you described you were doing) -- verify in the Channels window that the RC control is not commanding a throttle increase. I can't imagine why it would but it's worth eliminating that as a possibility. Can you also verify that all the BL-Ctrl's are showing green LEDs on the underside of the Power Distrbution Board? Then I would run the MK Tool motor test just to verify that the "throttle creep" doesn't happen with MK Tool controlling things. Try it first on each individual motor, then try it on all and see if you can replicate the problem. If you can replicate the problem, then I would suspect one or more of the BL-Ctrl. I doubt it will be all the Bl-Ctrls from what you say, but the motor test might help narrow things down. Let me know what you find. Andy.
Oh yeah, feels great! ha, ha... I seem to always "acquire" issues nobody else has seen. I cannot replicate the issue on the bench. All lights are green on the PDB. No errors in MK tools. If I use the motor test to increase/decrease the power, all is fine. If I use the MX-20, the creep occurs after the firs raise in throttle and back to zero. But when connected to MK tools, as the throttle creeps up, the "gas" value does not change. Here is a video:
Thanks for the video, Scott. I see what you mean. Your bench test eliminates some things. I'm grasping at straws here, but have you re-calibrated the ACC? I've got a flimsy theory that after you first goose the throttle, the flight control board thinks it's flying (for some value of flying) and is trying to "level" the C8 by increasing the throttle asymmetrically on the motors. I've not had a long hard look at the code for the Flight Control board so I have no clue whether this idea is crazy or not. But it might be worth a re-calibration, just to eliminate that possibility. Andy
Just a follow up, I did re-calibrate and the problem is much less apparent. I still notice it creep a little bit, but nothing I am overly concerned about. Its up and flying again, and seems to act "normal" (as if flying one of these things is normal). I'm now moving on to doing some video/camera testing, you know, the thing I bought it for in the first place...
Oh, yeah. The camera thingy. It's easy to forget with all the tweaking and fettling that we have to do for the airframe..... Andy.