Eureka Mignon Specialita King Size Dial for Espresso

Other large dials have ~ 1:3 gear ratio and fairly small dial, which is not sufficiently precise for espresso, especially if you grind extra fine for small doses. This dial is whoping 6cm in diameter and features 1:1.3 ratio, and full 240 steps! That means that every step is just 2° or in other words, 180 steps for one full turn.

Now, you might find the model a bit overengineered, but in the end it is super easy to print and use, requires no magnets, no mid-print fillament changes (only in first layer), and fits just on two printbeds.

Printing instructions

• Preferably PETG, as PLA does not work well for the knob (too much friction on the screw)

• 3MF project file for Prusa Slicer is the easiest way to print it, otherwise STL and STEP files are provided

• Files suffixed with ‘text’ are the complementary files for each object that shall be printex in contrasting color

• If you have no MMU an no multicolor-printing experience, follow these instructions

  • In Prusa Slicer go to Printers → General → Extruders → 2

  • Then go to Printers → Custom G-Code → Tool Change G-Code: Fill in this

; TOOLCHANGE_GCODE
{if previous_extruder != -1} ; avoid an annoying M600 after the initial prime.
M600 ; triggers the actual color change
{endif}

• When importing STL/STEP files to Prusa Slicer, if you put in at the same time pair of object + text, it offers you option to import it as one multicolor object - accept it

  • Then you can just select different extruder for the text and for the object, and when fillament change is needed, your printer will prompt you for manual fillament change.

• Layer height - first layer shall be 0.2mm for the multicolor prints to print easily, the knob thread should be 0.10-0.15 for better results, the rest is up to you.

Installation video is the most easy way to learn how to put this together.

Step-by-step instructions if you cannot watch the above video:

1. plug the dial arrow on the base

2. remove screw holding the bean hopper

3. remove knob for grind size adjustment by screwing it all the way out counterclockwise

4. put base on grinder

5. put back the bean hopper screw

6. put dial on dial spur gear and place it on base

7. screw in the knob untill you find true zero - the dial is likely not showing a zero

8. turn the knob counter-clockwise until the arrow points to zero on the dial

9. separate the dial from the spur gear, from the botom left corner, so that the spur gear can rotate and dial still points to zero

10. now find a true zero again

11. click in the dial to the spur gear - your zero on dial now marks true zero of the grinder

12. put on lid

13. put on bean hopper and screw it in place