Thank you! And even better that the end result flies really, really well! Which was a little unexpected, but I'll definitely take it... :-)

Thank you!
And excellent, yes the 3" X8 has definitely become a thing, but with good reason if this one is anything to go by, it's enormous fun to fly!

So, obviously the 1st ESC is just plugged into the FC socket, which gives you power, gnd, current (probably), and the m1-4. And for the 2nd ESC you don't need the power or current, but yes you DO need the gnd to complete the signal circuit back to the ESC from the FC. And then m1-4 leads solder directly to s5-8.

I have had issues with FCs having s1-8 pads, but only 6 of the connections supporting DSHOT - 2 of them weren't digital, which meant I had to drop all of the motors back to MultiShot or OneShot. The Matek boards don't have this issue, s1-8 all support DSHOT.

Unfortunately I haven't had the chance to test out RPM filtering with this build, as I foolishly ordered BLHeli_S ESCs, and had them installed before I realised my mistake. But it could be an issue, even an F7 processor might not have enough headroom for all that filter number crunching, I too have heard the same, but I really don't know. Maybe you can try it and let us all know! :-)

But I look forwards to seeing your build! What are you doing for the frame? Big Baby? Or DIY-ing it?

Thank you so much for this detailed explanation! This really cleared my wiring plan.

Yes I'm doing the big baby, with a lumenier f7 that is also supposed to do 8 dshot straight up, that's why I'm tempted to try rpm filtering, but I figure i'd have to turn the gyro filter way down so I'm pretty torn (but to be honest there is no freaking way I don't try it at some point). I also want to put 4 blade on top motors and 3 blade bottom to maximize grip and make it queiter but idk if this is a good idea either, maybe it'll mess up the coaxial motors too much.

Will post it once built and definitely credit your help! btw awesome flight video and location, and I know it has a lot to do with your stick control but damn this thing moves so crisp across all axis.

Well, good, I await the results of your brave filtering experiments! :) And yes, I am always very nervous about mixing props, but that is based on no actual information, just that "it doesn't seem right", but that's hardly a scientific approach. One thing I have read is that with contra-rotating props, the back prop helps 'untwist' the air from the front prop, giving a smoother thrust, but whether that has any real effect for a 3" quad is hard to say.

But yes, the thing is basically a ball of props, so it really grips tight and you can throw it about in a very agreeable manner!

Thank you! :-)
Well, I do like the challenges building brings, frustrating though it can be, I love that you can create these bonkers machines of all shapes and sizes and almost unexpectedly they still fly (often really well), and I am resigned to never being much of a pilot, so I might as well put my energies into building lovely robots! ;-)

Thank you! Yes, it's been a good project, and because I took so much time, actually surprisingly painless, given all the wire stuffed into such a small volume. I'm pleased with it - now whether I will actually fly it much, that's another question. But it looks great on the shelf, at least. ;-)

What?!?!!? NOOOOOOOOO
Why would you not fly it?

Actually, after testing it yesterday, I have shifted my opinion and now think I might be flying this quite a lot! It was really more fun than I had expected! :-D If I can just get a bit more battery life out of it... I put on some less aggressive props today, I might get to run some further tests this afternoon if I am lucky. I also just reprinted the GoPro mount - I had originally set it to 25º but the machine wants more of an angle than that, so 30º it is. More news when I have it to share.

So I just wanted to let you know, having taken the GoPro off, put an Insta360 GO on, and put a whole pile of packs through it, this little X8 machine is absolutely one of my favorite machines of all time. I thought it was a bit of a novelty build, but without the weight of the Hero7, it's an absolute acro star, it really is. If this bites the dust, I will definitely build another one!

I know, but it's quite a tall frame, so there was actually plenty of vertical height (well, 'plenty' as far as a 3" build goes). It was a surprisingly easy build, considering all the components. And it flies really well too! :-)

Thank you! Yes, there was a lot of wire to wrangle, but ultimately a fun and satisfying build. And it flies too, which is always a plus! ;-)

Thank you! Although we shall have to see how well it actually flies, of course; although it does fly, which is encouraging. But yes, it came out pretty neatly and has a nicely chunky aspect - I kind of reminds me of one of those very colourful jumping spiders; kind of squat, sort of ugly-cute, and a little hydrocephalic.