Supernote Retractable Pen
Why a Retractable Pen?
The pen is the most critical interface in the digital writing experience—it connects thought to the screen. Ratta’s Supernote stands out not just for its software, but for its hardware philosophy: the ceramic nib. Unlike traditional nibs that wear down and require frequent replacement, the Supernote ceramic nib effectively lasts forever.
Because Supernote sells the “Refill” module independently, it opens up a world of customization. I wanted to move away from the standard capped design to a retractable mechanism (clicky pen). A retractable pen offers better convenience—no cap to lose—and a more satisfying, tactile engagement when starting a writing session.
Materials Needed
| No. | Part Name | Note |
|---|---|---|
| 1 | Supernote Pen Refill | Original Supernote refill module |
| 2 | PEI 2080 Short Pen | Only the short pen version fits the Supernote nib dimension |
| 3 | 3D Printed Adapter Parts | Download and 3D print the adapter parts |
Caution: The Supernote refill contains a delicate copper coil that is essential for EMR functionality. Any damage to this coil can render the pen unusable. Handle the refill with care during disassembly and assembly. DO not apply excessive force or attempt to modify the coil in any way; DO not hand-touch the coil directly with hands, try to wear a glove or hold it from the plastic parts only.
The Challenge: Precision Fitting
Creating a reliable retractable mechanism for the Supernote refill isn’t as simple as swapping a cartridge. I conducted a large number of experiments to get the tolerances exactly right.
The fitting is paramount for two key reasons:
- Protection & Safety: The ceramic nib is durable but brittle; the mechanism must protect it when retracted. More importantly, the sensitive copper coil inside the refill must not be compressed or damaged by the internal mechanics, which would ruin the EMR signal.
- Mechanics: The retraction needs to be smooth and consistent. If the refill isn’t seated perfectly, the writing pressure can cause it to wobble or retract unexpectedly.
Assembly
Prepare the Pen Body: Disassemble the PEI 2080 pen completely, removing the original ink cartridge and the stock spring. Also remove the tail tube from the Supernote refill, we are going to use our custom adapter instead.
3D Print the Adapter: You can print the adapter parts using PLA or PETG. The parts consist of two halves that clamps around the coil section of the refill, and a tail piece that fits into the pen body.
Fit the Adapter: Slide the custom 3D printed adapter onto the tail of the Supernote refill. This protects the coil and provides a solid surface for the retraction mechanism to push against.
Insert: Carefully insert the refill assembly into the pen barrel. Screw the front cap back on. Ensure the ceramic nib flows through the opening smoothly without friction. Click to retract and extend. Verify that the nib is fully protected when retracted.
Final Result
Enjoy your new retractable Supernote pen! The mechanism should provide a satisfying click and smooth operation, while keeping the ceramic nib safe when not in use.
