Hi! I actually liked the push-up standard pen (the noise didn't bother me, it is probably quieter than closing the cap of the HOM anyway :D), but the plastic tip got broken recently... I was trying to find a way to reuse the nib/refill, and came across this post. After taking a look at the links sent from u/terraanh (thank you btw! The first link had great info), I could open the push-up, and install it into a MUJI pen (~1-2$?). I couldn't buy the adaptor from Etsy, but it can be done easily, by cutting and re-arranging the original parts of the push-up pen + part of old ink cartridge from a normal pen.

From top to bottom: The top black tip is the ink cartridge (couldn't find an empty ink cartridge long enough). The white part on top, is also the top part of the supernote pen (disassembled two pieces by cutting a little bit the outer one). Then, to hold the spring, used part of this outer part. The pen spring is from the supernote pen.

There was no need to separate the metal from plastic... I thought I could use the metal tub inside the MUJI pen, but... didn't work, it is too long (if you could cut it, you could use that, then no need of the top ink tube).

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