Japanese eyedropper

[verulean]

Just finished another kitless pen! This time I wanted to experiment with an internal filling mechanism. I'm partial to Japanese eyedroppers in my personal collection so I ended up going that direction. The eyedropper mechanism is made from a stainless steel rod, cork packing material, and delrin for the conical shut-off valve and packing retainer.

I also tried my hand at making a spring-loaded inner cap seal, inspired by the Platinum slip and seal mechanism. The inner cap is also made from delrin, and has a 45 degree chamfer on the inside edge to help center it on the section lip. There's a step inside the cap that limits the inner cap's range of motion.

 

[PenCasso]

True artist!

 

[darrin1200]

That inner cap seal is awesome. I may have to give that a try.
How does the eye dropper work. Doe the piston unscrew, creating a path for the ink? Does the piston stay out, like in the 2nd photo, the whole time you are writing.

TrueType an amazing pen.

 

[duncsuss]

This is beautiful, and technically very advanced - but I think you have the wrong terminology for the fill type.

"Eyedropper" usually means "an empty barrel that you fill using an eyedropper, or syringe".

I think what you have here is the far more sophisticated "vacuum fill" - where you push the plunger into the barrel creating a partial vacuum in the space behind the washer. Pull the plunger out, dip the nib into the ink bottle, and push the plunger in (blowing bubbles out through the ink.) When the plunger reaches the end of its travel, the internal bore widens and the vacuum in the barrel sucks ink from the bottle.

Great job on that and on the cap seal.

 

[verulean]

That inner cap seal is awesome. I may have to give that a try.
How does the eye dropper work. Doe the piston unscrew, creating a path for the ink? Does the piston stay out, like in the 2nd photo, the whole time you are writing.

TrueType an amazing pen.

It still fills via syringe or eyedropper like a regular eyedropper pen, but the "piston" either has a conical profile on the end that mates with a matching conical surface at the end of the section, or an O-ring to make the same sort of seal. When the knob is fully tightened down the barrel is sealed off from the section.

The section still holds a bit of ink itself (maybe 0.5-1mL in mine), plus what's in the feed, so even while sealed you can still write for a while, then crack open the knob to let more ink through. I usually leave it open all the time while writing. The idea is to let you seal/unseal the main ink reservoir to prevent burping or leaks.

 

[verulean]

This is beautiful, and technically very advanced - but I think you have the wrong terminology for the fill type.

"Eyedropper" usually means "an empty barrel that you fill using an eyedropper, or syringe".

I think what you have here is the far more sophisticated "vacuum fill" - where you push the plunger into the barrel creating a partial vacuum in the space behind the washer. Pull the plunger out, dip the nib into the ink bottle, and push the plunger in (blowing bubbles out through the ink.) When the plunger reaches the end of its travel, the internal bore widens and the vacuum in the barrel sucks ink from the bottle.

Great job on that and on the cap seal.

"Japanese eyedropper" is a twist on the standard eyedropper that's roughly a vacuum filler "without the vacuum." The rod is used to seal against the section when closed, but doesn't have a gasket that seals with the barrel wall to form the vacuum. Some articles on the mechanism:

• Akashic Blog
• Richard Binder

 

[Jim15]

Awesome work.

 

[Oliver X]

Nice work! I don't see too many people making Japanese eyedroppers these days. I've made a few and they're certainly a lot more work than making a cartridge pen.

 

[duncsuss]

"Japanese eyedropper" is a twist on the standard eyedropper that's roughly a vacuum filler "without the vacuum." The rod is used to seal against the section when closed, but doesn't have a gasket that seals with the barrel wall to form the vacuum. Some articles on the mechanism:

• Akashic Blog
• Richard Binder

Thanks for this information - it's a variety of ink system I'd never encountered before. I'll check out the links.

I stand by my comments regarding the beauty and skill of the maker