What is the trick to making this work? I tried the modified Ahab feed and, indeed, it does write with a better, more controlled flow.....for a few lines. Then it dries up and I have to shake the pen to restart it. Writes beautifully again for a few lines, then requires another shake.
I though it might be due to the absence of the little extension seen on the "native" Visconti feed, so I fit a short feeder tube into the Ahab feed, but same problem.
This is pretty frustrating. The HS is a unique pen and I love the way its Pd stub nib writes, but the gushing flow is an issue and also affects the limited ink supply. (Why do they do this? The old Manhattans had a much larger bore and hold a LOT of ink, but the later generation piston fillers have a much smaller internal diameter. Even filling with the ink pot and multiple strokes doesn't achieve much more than approximately 1.2 cc of ink.
I agree with you about the ink supply. It's almost like the pen was made to not be used. I figure the captured converter is there because the body is made from a porous material?
As for the ink flow, with these ebonite feed swaps, I find that you want the feed as close to the tip of the nib as you can get it, then have the whole package as far into the pen as you can get it. The air-ink interchange is being disrupted. Either by a significant imbalance between flow of ink and return of air, which I don't think is an inherent problem of your setup. More than likely it is flowing weird because of some unlucky-Ness and you may just want to pull it out, clean it, make sure there are no bits of ebonite, then put it back in. You didn't widen then slit on the nib side did you? The feed is designed for high flow flex writing, and I think it would benefit from a flow reduction. I think the nib is holding back a big flow ink, rather than the feed and nib being in close balance. The pressure imbalance is too great. It's what happens in eyedroppers sometimes. It's how a super wet eyedropper can run dry every few minutes.
I have to go to the airport now, but I'll keep an eye on your posts. I think I have a very very minor version of your problem, where once every two pages the pen stops for a letter or two. I'll ink the pen up today and write with it, and see.
We'll get through this together, haha.