Muji click pen + Supernote Ceramic Refill mod (no 3D printing needed)
inspired by u/accidentalcomma's great post (where he used a Standard Pen refill), I tried the same with the Supernote DYI Refill.
With some trial & error, I managed to get the Supernote Refill inside it without 3D printing parts and with the clicking function intact. Here's how I did it:
What you need:
I have realized there are multiple versions from Muji pens depending on year of production and even country, so this applies to:
- pen: „Smooth Gel Ink Ballpoint Pen Knock Type 0.5 Black“ / Muji number 4550002794118
- Supernote DYI ceramic refill which you can get on their website (be VERY careful to never touch the copper wire and coil on the front, as this will disable the function)
- the Muji gel refill that comes with the pen, thoroughly cleaned with out residue inside
- an additional empty gel ink refill, thoroughly cleaned with out residue inside (I used Pentel 0.7 gel)
- exacto knife
- ruler
- some electrical tape
Disclaimer: Please do at your own risk, I only used it since yesterday - works fine so far, but no guarantee that it is a 100% solution (especially the spring part could be tricky over time).
Parts
(see drawing on Supernote Manta in pic for reference):
A (tube piece about 20 mm)
- large enough interior diameter to let the refill move freely inside
- small enough outer diameter so it fits inside the pen case
I cut the part from an empty Pentel gel ink refill, the part with the wider diameter (the Pentel refill has a tighter and a wider diameter within the plastic tube)
B (about 45 mm, depending on the spring)
- large enough interior diameter to let the refill move freely inside
- small enough interior diameter so the spring rests on top of it and does not move inside the tube
I used the Muji refill from the pen (empty it if you must, but be careful, it has a sticky gel inside and clean it thoroughly)
It does not work perfectly in my case, as you can see the spring has been squeezed into the tube a bit – but still works
Spring (between B and C)
I used the spring from an Uni Ball One F pen because it looked sturdier than the original Muji spring
so if you use the original Muji spring, maybe you need a bit longer tubes (I threw it away and cannot compare size to the Uni Ball spring unfortunatley)
C (about 6 mm, depending on the spring and part B)
needs to be so tight as to grab onto the Supernote refill rear part (best even attach it with the electrical tape). This tube part should not let the Supernote refill move inside itself, but sit tightly on the rear part of the refill, since this is the part where the push action gets transferred to the Supernote refill and pushes it down/up towards the spring.
I used an empty Pentel gel ink refill, but for this the part with the tighter diameter
also I taped it onto the Supernote refill
D (about 15 mm)
Just a spacer part, I used a cut part from the original Muji refill from the pen for this
Assembly
Put part A into the tip part of the Muji, then put carefully the Supernote refill inside. Put part B on top of Part A over the Supernote refill. Put the spring above part B.
Now put the "tighter" tube part C on top of the Supernote refill so it sits there tightly, fix with electrical tape so it won't move along the Supernote refill (where exactly you put part C will also determine the length of the spacer part D)
Put the spacer part D inside the top part of the Muji pen.
Assemble the two pen parts and make sure all parts are aligned.
Enjoy!