1Zpresso – J-Max Grinder

J-Max manual coffee grinder
J-Max manual coffee grinder
J-Max grinder

User Instructions

J-Max manual coffee grinder

Adjustment

  1. The grinder is ready to use out of the box. Turn the adjustment dial ring counter-clockwise all the way to the starting point where the resistance starts and the crank handle can’t spin freely. The #0 will be aligned with the scale mark and the bottom edge of the adjustment dial ring will touch the first tier of the scale mark.
    jmax-coffee-grinder
  2. The pyramid-shaped scale mark consists of multiple squares that indicate how many rotations you are at, and it gets smaller while you set coarser settings.
  3. There are four and a half rotations in total. 90 clicks in a single rotation and each click moves the burr by 0.0088mm/8.8 microns.
  4. Turn the adjustment dial ring clockwise to find the grind setting:

    • Turkish Coffee – 70 clicks
    • Espresso – 120 clicks
    • Aeropress / Moka-pot – 190 clicks
    • Pour-over – 270 clicks
    • French press – 360 clicks

      Refer to the grind setting tutorial post for different brewing methods.

  5. Attach the rubber band to the grinder for a better grip.

    J-Max grinder


  6. Put coffee beans in the hopper and turn the handle clockwise to start grinding.
  7. Follow the guide to calibrate the grinder after disassembling and reassembling the grinder.

Disassembly

Warning: Do not loosen the burr ring unit before step 3.

J-Max manual coffee grinder
  • Turn the adjustment dial ring clockwise by around two rotations and remove the knurled thumb nut counter-clockwise while pressing the burr.
J-Max manual coffee grinder
  • Remove the upper bearing cap and upper bearing.
J-Max manual coffee grinder
  • Remove the burr and central shaft, spring and lower bearing cap.
J-Max manual coffee grinder
  • Turn the burr ring unit forward (reverse threads). Disassembling the adjustment dial ring is not suggested.
  • Do not clean the grinder with water. Cleaning with a brush and blower is recommended.

Assembly & Calibration

J-Max manual coffee grinder
  • Turn the burr ring unit backward (reverse threads) to the tightest position.
J-Max manual coffee grinder

  • Align the #0 with the scale mark and the bottom edge of the adjustment dial ring touches the first tier of the scale mark.
J-Max manual coffee grinder
  • Put the components back in the right sequence: lower bearing cap (the raised edge side facing upward), spring, shaft and burr.
J-Max manual coffee grinder
  • Put the upper bearing back from the top.
  • While pressing the burr from the bottom, put the upper bearing cap back. The side with concave dots faces upward, and the U-shaped hole fits the shaft properly.
J-Max manual coffee grinder
  • Tighten the knurled thumb nut to calibrate the grinder while pressing the burr from the bottom.

    Note: There are four and a half rotations in total counted from the starting point. The starting point might be different within ±10 clicks due to the strength you tighten the nut and dial.

Warning

Do not disassemble the following components any further:

J-Max manual coffee grinder

The Burr and Central Shaft

J-Max manual coffee grinder

Burr Ring Unit

J-Max manual coffee grinder

Bearings

Precautions

  • Do not clean and wash the grinder with water.
  • Do not wipe your grinder with solvents other than water and alcohol.
  • Keep the grinder in a dry environment in order to extend its lifetime.
  • Follow the instructions of re-assembly, ensure to place the components into the correct positions.
  • Keep the grinder away from children for safety concerns.
  • To prevent the knob from being damaged, putting the grinder and the handle in the case as below picture is suggested.
J-Max manual coffee grinder