Nozzle Size Indicators for Prusa i3 MK3, MK3S, MK3S+, MK4, MK4S Printers

Don't just guess your nozzle size.. Be sure of it!

This frame attachment is for those who have multiple Prusa printers and utilize a variety of nozzle sizes for your prints. These nozzle size indicators offer a simple solution to knowing which nozzle size is on which printer at a glance.

Snap-fit Nozzle Size Indicators

These indicators snap directly onto the top of the aluminum frame on any Prusa MK3, MK3S, MK3s+, MK4, or MK4S - just like Prusa's factory spool holders. Once installed, the tolerances are just loose enough for you to slide the indicator back and forth to your liking.

Available Nozzle Size Indicators:

- 0.25 mm

- 0.4 mm

- 0.6 mm

- 0.8 mm

Instructions & Suggestions:

- Slicing the Model

- Infill - 100% *****

- Brim - None

- Print Orientation

- Rotate 90 degrees so that the model forms a "C" flat on the print bed *****

- *If you don't orient the model properly & use 100% infill, the print will almost certainly snap during installation

- Paint-on Fuzzy Skin

- Once rotated, only select the left, right, and front faces.

- Be sure to select any of the smaller faces inside the numbers as well

- Fuzzy skin settings: 0.3mm thickness & 0.8mm point distance

- Paint-on Supports

- Enable smart-fill, highlight overhang by > 25, smart-fill angle > 15

- Enable "support enforcers only" before slicing

- Installing the Nozzle Size Indicator

- Place top of the indicator on the aluminum frame first

- Apply a moderate amount of pressure downwards & into the frame to snap the indicator in place

- Slide the indicator left/right to your desired position

- Colored Nozzle Size Numbers for Greater Contrast

- Easy Way

- Apply some acrylic paint to the inside face of the numbers

- Tricky Way

- When slicing, orient the model so the face with the nozzle size on it is flat on the print bed

- Use the color change slider to initiate a filament change before the face of the numbers appear (if using 0.3mm layer height, this will be at 1.4 on the color change slider)

- Initiate another color change at least 3 layers after the first one to return back to the primary filament color (if using 0.3mm layer height, this will be at 2.3 on the color change slider)