I have recently assembled and flown my custom designed Y6 hexacopter but have found that there is a lot of pulsing going on in position hold mode. Does anyone have any ideas on if this is an ESC issue or can it be tuned out with the Pixhawk? The hexacopter uses 6 of the large U7 motors by T-Motors and has been designed for heavy lift video work. I have 16'000MAH of battery slung underneath and hover is in the 35% throttle range so plenty of scope for a DSLR.
The YouTube clip below shows the Y6 in hover with the pulsing audible.
https://www.youtube.com/watch?v=5WQ6z4_XZ8U
Any advice would be greatly appreciated.
Replies
Did you have any joy getting to the bottom of this? I've got the same on a new frame now - perhaps a bit worse.
I was flying light today, no payload (600g), hover at 42ish% and loads of pulsing.
Did not do an auto-tune as I did not have the payload and there was too much of a breeze.
Cheers,
Crispin
Hi Crispin,
Sorry to hear you have the same issue!
I am actually going to be selling my Y6 project off and haven't had a chance to revisit the pulsing issue. I am now running Rc3.3 on the pixhawk and hoping that an auto-tune will sort the issue out. RC3.2 was almost impossible to land as the pixhawk would not disarm on touch down!
I will let you know when I get a chance... possibly this week as it is finally summer in Oxford!
Let me know if you get yours sorted.
Cheers,
Ben
That's a bummer... When you say "Would not disarm" is that after an auto landing?
If you're going to sell it, PM me the details when you ready - if the price is right I might take all or any bits you're willing to sell (just frame etc)
I'll take mine out again tomorrow and see if I can get it tuned.
Have you looked at your logs? If the PIDs are too high they could cause pulsing like that
Thanks, just about to take a look now..... will let you know what I find!
Sorry Ben, can't really help you with that - is it a tuning issue? Have you tried the auto-tune? Perhaps there is a problem because the hover throttle is so low that it's "hunting"?
What I did want to ask though - what frame and more specifically, what motor mounts are those?
Cheers,
Crispin
Hi Crispin, Thanks for the reply! I have tried going down the autotune route with no luck yet. I am hoping that it is related to flying under design weight.....maybe on the next flight I will try add a couple of kg?
The frame is 100% my design. A mixture of carbon and high end 3D printed parts! I've attached another image if you wanted a closer look!
IMAG1443.jpg
Drool. Spectacularly cool frame that. Not sure about those two white ducked fans. Not sure if they'll add to the lift :p (I know they're not ;) ) In particular I like the motor mounts. What are they printed with? Just ABS or you using the CF ABS? I'm designing my own for use on an own-build so very curious about other designs.
Regarding your pulsing though, something I noticed on my latest build is a sort of bounce my frame has while in hover. It's also a bit over powered (about 40% on throttle for hover) when unladen. When you load it up with camera (600g) and two batteries (1.2Kgs) I think there is a bit of flex in the arms. Dead calm air, auto-tune complete, stable as a stable thing but there is a weird bounce in when in a hover.
Not a help but just throwing it out there in case it helps.