I got the urge to build a Y6, as one does from time to time, and rather than get myself a dedicated frame, I wanted to convert an old school frame - something I have done before when building an only marginally successful Y4 machine. I previously used a Realacc Real3 frame in the Y4 build, but that frame has long since ceased production. However, after trawling around Banggood some, I discovered that HSKRC offer a clone frame, so I grabbed myself a couple of those and set to.

The frame lends itself curiously well to moving the rear rotor arms into the middle, there are handy bolt holes already available, and the double top-plate is ideal for doubling-stacking the rotor arms. I had to drill out holes for the 20x20 stack, but otherwise there were no frame modifications needed. The camera cage is designed for a big ol' full sized camera (remember those, kids?!), so I had to print up a sizeable chunk of TPU to make the camera touch the sides, and to push it forwards enough so that you see something other than cage.

Because I wanted to use a Caddx Vista in this build, and because there isn't a good way to side-by-side two stacks, I went for one huge stack and so had to increase the depth of the frame's belly by printing an extension. But this did also give me somewhere to put the Crossfire antenna mount. And it meant that the whole machine was raised up enough so the lower motors don't touch the ground. It all worked out pretty well.

Part of the problem with a Y6 is that it is of course a hexacopter, and so you have the ESC issue. I only know of one 6-in-1 ESC, and that's for a 3" or below builds, so for this machine I went with my only real choice, old fashioned arm-mounted ESCs. I chose Flycolor X-Cross Slims - they only go up to 5S, but I only fly 5S, so no issues there, and they are, as the name implies, nice and slim and fit the rotor arms well. But this then means an absolute rats nest of wiring, both power and signal times 6. Because I really didn't want a mass of red, black, and yellow wires - I had a green and purple colour scheme in mind - I somewhat obsessively replaced all the ESC leads with green and black wire. It had to be done. I'm sure you understand.

As for power, I found a nice Matek PDB designed for 6 motors, with signal routing pads that feed a plug connection to a flight controller. Not quite as good as a 6-in-1 ESC, but about as good as I was going to get. Using the plug did mean that there were still two more signal wires that needed to be hard-soldered between the PDB and FC, but again, even if the plug is only a partial solution, anything to reduce the soldering needed on a 20x20 board. Unfortunately the supplied Matek cable was inordinately long, and because of the way the frame's belly hinges open and where the RX needs to be, the receiver leads needed to be annoyingly long too, and so the build has ended up with a whole mass of far-too-long cabling. But there is plenty of space in that extended belly, so it's not really a problem, potential RF interference aside. But it does upset me a bit, though.

Cable management issues notwithstanding, this has come out about as well as I hoped, and it has passed the backyard hover test - it has both the oddly locked in feel, and the throaty roar of stacked contra-rotating machines. It's pretty heavy, so it might end up being a battery killer, and should I even be trying agressive acro with something like this...? Flight tests soon.

UPDATE 2022-01-02
Well, it flies. And then some. This is stock BF 4.2.9 without RPM filtering, running a 1300mAh 5S. It is a bit more power hungry, of course, but not as bad as I feared - 4mins from a pack is fine. And it is fast, and extremely locked in, the yaw handling in particular is very crisp. The props are of course in view, but it's not terrible, and the geometry that goes with this view seems to be working nicely - you can throw this thing about which I wasn't really expecting - so I'll put up with the minor obstruction.

This is a bit of a winner: