I long lamented the non-existence of an auto-advance cartridge. It seemed so obviously awesome and worthwhile — the ultimate swappable component in the MP world, a self-contained mechanism of the coolest kind.
Then a few weeks back I learned of an auto-advance cartridge from someone on Knockology. Unfortunately, multiple recent searches for their comments about this item came up empty, so perhaps the chain was deleted. If someone can find that chain and provide a link, I’d appreciate it.
Kayou makes this cartridge and serves it up in a retractable format that is fairly identical to the operation of a retractable ballpoint. The outside diameter of the cartridge is 6.22mm and fortunately it works with many pens. It requires very minor effort to add an extension to get the length right.
The version I am familiar with is the Ultraman branded edition. There are several colors and characters emblazoned on the pencils from this series, but I bought the one with the simplest black cartridge. It simply says ‘Ultraman’ in silver text on the cartridge. The Ultraman character theming is the real branding on these pencils. The ‘Kayou’ brand is not even on the box, but it does appear on the center of the pencil.
Here I fitted it to a Sakura Ballsign ID Pen. I am testing it out on various pens and pencils. I haven’t found an MP that can accept it without modification, but I am still working on it. Pretty fun.
Leads are inserted through a small hole in the tail of the cartridge. It has some sort of funnel so it’s basically impossible for them to fall back out. The drawback of this cartridge is I’m not sure how it can be repaired if it gets jammed.
Please report on the feeling and the performance: the pen is quite something, and the perspective of modding it into a never-skipping pencil is too tempting to resist.
Many thanks to @amjacobs7 for helping me to get a hold of this Kayou auto-unit pencil. Some quick notes:
The way the cartridge works, you have to treat the converted pencil as a pen. You just leave the lead advance to the tip – you cannot click it by yourself. If you manually push back the tip, lead will advance by a fair bit… AND you cannot push it back in. Even if you keep the tip fully depressed, it doesn’t open the clutch. So this is strictly a one-way affair.
The package comes with 90mm long leads, and they also feed one-way through a small hole in the back of the cartridge. It takes 1 piece of lead at a time… welcome back to the user experience of the very first generation of knock pencils!!
And here is their webpage with pictures of their pencils but not much more detail… although you can see some other non-Ultraman versions that might make it easier to find elsewhere:
