⚠ Note: This is the very first prototype of the ROPI grinder. It works, but it’s basic. If you want the latest and fully refined version with stash chamber, durability upgrades, and smoother grinding, check out 👉 Herb Grinder ROPI with Stash Chamber V4.

This is where the ROPI journey began — the original 3D-printed grinder prototype developed in 2022.
It was created to test the concept of a magnet-based modular grinder and became the foundation for all later versions.

Key Features of the Pilot Version:

• Magnet-based design for secure closure and easy handling
• Basic grinding chamber with simple hole pattern (functional but less optimized than later versions)
• Durable enough to prove the concept despite its early design
• A true proof of concept that inspired V2, V3, and the current V4

Printing Recommendations

• Material: PLA recommended (PETG also works)
• Layer height: 0.2 mm
• Infill: 20%
• Supports: Only needed for the middle part. Do not support the magnet holes on the middle part.
• Magnets: Neodymium magnets 5 mm × 2 mm (10 pieces). Orient carefully and use a bit of glue for a secure fit.

Parts to Purchase

Neodymium magnets 5 mm × 2 mm (10 pieces)
You can buy them at a local store or order online (e.g., Amazon) for example here.

Clean-Up & Assembly

• Clean surfaces with an iron brush
• Use a heat gun to remove thin threads
• Trim imperfections with a scalpel or knife

Inserting magnets:

• I use a screwdriver with a flat bit surface
• Attach the magnet to the end of the screwdriver
• Apply a small drop of glue
• Push the magnet into place while holding the handle of the screwdriver

Something to Keep in Mind

This pilot version is functional but lacks the refinements of later versions (stash chamber, optimized printing, durability upgrades).

For the best experience, check out the latest release:
👉 Herb Grinder ROPI with Stash Chamber V4

Community & Licensing

• If you like this model, please download, test, and leave a comment (I read and reply to all of them). A like is also very appreciated!
• Remixing and personal use are allowed.
• For any commercial use—such as events, branding, or resale—please contact: info@ropi.tokyo
• We are also open to commercial partnerships to promote and sell the grinder.