I don't have any pictures of the universal mount at the moment, as I'm currently prototyping the official 3MS enclosure, which will include a mainboard case.

That's great news!

Hi @bsafh, the 3MS now has an official enclosure! https://www.printables.com/model/1108644-beta-3home-3ms-hybrid-official-modular-enclosure

I'm not sure about the cutter, but you should be able to use the existing filament runout sensor as an extruder entry sensor in Happy Hare.

Your need for a filament buffer will depend on the distance your filament has to unload during color swaps.

So it's best to place the y-splitter (X-in-1) as near as possible to the printhead and have X long reverse bowden tubes to the filament spool position?
That should make filament switches faster as well?

Yes. I put it further away to make the overall setup a bit cleaner, but putting it closer to the tool head is best for speed.

you should be able to use the existing filament runout sensor as an extruder entry sensor in Happy Hare

Well, yes, in principle. In real life the switch in this runout sensor and/or the housing is terrible: you can't push the filament through smoothly. It nearly always gets Stuck and you have to move it backward/forward before it finally pushen through. Not good for automatic filament change.

Any ideas for a better sensor that might fit to the existing screws on the holding plate? Perhaps any optimal sensor for a smoother filament path?

Something else: as you can see, this is a Titan extruder - would it be beneficial/advisable to replace it with a BMG Clone extruder?

Sometimes the filament does not push through the extruder on loading, the tolerances of the output plastic tube seem to be to big that it can move a bit, partially blocking the International filament path.

I'm not sure about the cutter

I'm still searching ... :-(

Perhaps something like this would fit?
https://www.printables.com/model/826577-3d-underclippy-v2-filament-cutter-for-3dchameleon

But the printhead assembly on the Tronxy is really tight. :-(

Is it possible to use a servo driven cutter with e.g. the BTT board + HappyHare? I don't like to bump the toolhead into the frame for every filament change, that adds lots of travel time...
(if I can find any possibility to mount that at all ....)

@bsafh ,

Any ideas for a better sensor that might fit to the existing screws on the holding plate? Perhaps any optimal sensor for a smoother filament path?

The Filatector is a good inline option. You don't need any mounting for it, as it's coupled between your PTFE.

I'm still searching ... :-(

Perhaps something like this would fit?
https://www.printables.com/model/826577-3d-underclippy-v2-filament-cutter-for-3dchameleon

That may work...

Is it possible to use a servo driven cutter with e.g. the BTT board + HappyHare? I don't like to bump the toolhead into the frame for every filament change, that adds lots of travel time...

I would check out the 3DChameleon's Auto3DClippy.

more than 4 materials

Speaking of more than 4 filaments:

the only board listed for that seem to be the Mellow Fly D7 https://3dcoded.github.io/3MS/setup/controllers/mellowflyd7/#bom (if it is even possible to find one) or the Geeetech A30T board (but I really don't want to sonlder things.. (UART Mod)), both with a max of 6.

Are there any options to go beyond 6 filaments? Several boards? Can HappyHare handle that seamlessly? Or are there other MCUs for 8-10 extruders/steppers?

Hi @bsafh ,
To get more filaments, you can use multiple boards. For example, 8 filaments can use two MMB CAN's. Just submit a controller request issue and note that it's your 2nd, 3rd, etc. MCU.