Hypercube Hotend Mount for Chimera and BLTouch

The Chimera mounts I found for the hypercube were all bad matches for my bed position and some were straight-up broken meshes, plus I needed to edit them to clear the bolts holding the HC x-carriage to the bushes. I also had a devil of a job trying to get bushes to slide smoothly on my CF tubes - crosslaid are much stronger than pultruded, and vibrate less, but the outer diameter is very variable and even hours of careful sanding with 200-grit wet cloth wasn't able to get it totally even.

So I had 3 goals:

1) Create a hot-end mount for the chimera clone that fitted neatly without needing loads of cut-outs, that could take a 40mm part-cooling fan.

2) Design bushes that would run smoothly over slightly lumpy CF tubes without introducing more wobble than already there.

3) Mount the sensor somewhere that wouldn't add limits to X or Y travel.

The first bit was pretty easy - E3D make the tech drawing available and I borrowed the part-cooling fan duct from https://www.thingiver