Main plate Nextruder MK3.9/MK4 cho MMU3, chỉnh cho flex filament

According to the MMU3 assembly instructions, you shouldn't print your own Nextruder main plate! Instead, Prusa recommends using the one supplied because FDM printing cannot produce the same quality. The kit also comes with an extra main plate.

The new Nextruder idler lever that comes with the MMU3 kit should help prevent tangling by allowing the flex filament to be clamped more tightly, so it's unlikely you'll need this. However, if you still experience a tangle, use this modified main plate. The print settings below provide the highest quality possible.

PrusaSlicer settings

• 0.10 mm DETAIL preset
• Adaptive layer height set to maximum quality
• 3 perimeters (standard for this preset)
• Bridge speed set to 10 mm/s
• Support Material:
  • Suppor type: Snug
  • Top contact Z distance: 0.1 mm
  • Rectilinear pattern spacing 1 mm
  • Support on build plate only

PETG supports are difficult to remove from PETG, but with patience it can be done. It would be best to use an MMU to print PETG with PLA supports, which break apart easily with zero top contact Z distance.

Customizing

The arc is 2.9 mm tall, which provides a 0.3 mm gap between the arc and the gear teeth, preventing the flex filament from sliding off the gear.

You can use the OpenSCAD script provided to change the height of the arc. Making it shorter widens the gap. Don't make it taller than 3.1 mm or the arc may rub against the drive gear teeth.

Updates

2003-06-07:

• Changed bridge arc endpoints for better integration appearance
• Included two STL versions for 0.3 mm and 0.6 mm gap
• Photographs haven't been updated, still the old model