Y-Filament Combiner-Converts MMU Printer to 5+1

A Y Combiner that is attached on top of the MMU3 Selector front plate, which allows for direct single filament use (by disabling the MMU3 in the Prusa menus) OR by using the MMU3 for multi-material.  Gives the Printer owner a 5+1 Filament option and a rapid single filament load to the print head by bypassing the buffer.

I updated this part from PreZ's design because I wanted the functionality PreZ's design offers which is rapid 5+1 filament, but did not want to modify the MMU3 Selector front plate in a potentially irreversible way. 

The benefits:

Rapid addition of a single filament to printers equipped with an MMU3 by bypassing the native MMU3 buffer and MMU3 loading process if you just want to do a single color print.  It's easier to just have the filament go directly to the hot end, bypassing the MMU3.

This is especially convenient not just for using a spool quickly, but also when you want to print directly from your filament dryer.

The Y combiner is added between the output of the MMU3 and the hot end and fits over the native MMU3 Selector Front plate for minimal impact to the native part.

When you want to use the direct path (for a single color, simple print, or exotic material that either can't go through the MMU3), you just disable the MMU3 in the Prusa Settings menu.  When you want to use the MMU3, you enable it again in the menu.  But you don't need to detach PTFE tubes.

This model requires:

• 3xPC4-M10 PTFE fittings for the Y combiner
• 2x M3x14 screws
• 1x 445 mm PTFE tube with ID 2.5mm. Native tube is too short
• 1x 38 mm PTFE tube with ID 2.5mm to connect the Selector to the Combiner
• 1x Desired length of PTFE tube with ID 2.5mm to connect +1 filament spool to combiner

For those with enclosures, this design sits approximately 58mm higher than the selector.