Macap M4 Coffee Grinder Doser Mod in 5 easy steps.
Step 1: Buy one of the cheapest 58mm flat burr grinders out there.
Step 2: Gut it.
Step 3: Replace the mechanical doser with this simple (skewed) funnel.
Step 4: Drink an espresso.
Step 5: Pat yourself on the back for saving money and living the 3D printing dream.
See instructions for details.