I have a couple ebonite feeds from Sheaffer school pens and a couple from Connaisseurs, but am trying to understand how to manipulate flow (as my school pen feeds are a little stingy on flow). See attached.

This I understand: the ink enters groove on the center rod which sticks out the bottom of the main feed and travels along it into the center of the feed. Then it flows to the surface of the feed through a longitudinal slit under the nib. (Not to be confused with a breather tube. www.Richardspens.com explains the basics nicely in Feeds: Revolution, Evolution, and Devolution. But I am left with the following questions.)

What I don't understand: Why have a center rod at all? Why not just have ink enter through the hole in the bottom of the feed? Or why is the rod of that length -- and how would the feed behave differently if the rod was shorter, or if it was sheared off at the surface of the main feed?

I assume that if I took the center rod out of the feed altogether and just left the rod-sized hole in the feed, that perhaps surface tension would inhibit flow, or perhaps the ink flow would be too great because the resulting hole is too large.

If I pull the rod partway out of the center feed so that it is not pressed all the way in, how will that effect flow?

FYI: I am asking:

1. Out of curiosity, and
2. I am trying to determine how to increase flow, and
3. I want to use one in a piston-fill pen of another make, and the piston hits up against the center rod when filling the pen.

I could experiment, but I imagine someone already knows most of the answers here.

Thanks,

BruceW

If you pull the center feed out, ink will likely gush out through the fins like a fire-hose.

First thing to try to adjust with a feed is the gap between the feed and the nib. I usually do this by heating the feed (using either hot water or dry heat from a heat-gun - hot water gives better temp control, but can cause celluloid to discolor and will cause hard rubber to discolor - might not be as much of an issue with a school pen) and then letting it cool with a tiny shim of mylar between nib and feed - but there may be more subtle methods of setting it. Oh - and the general principle is to improve flow increase the gap, to reduce flow tighten the gap.

This is assuming you have flushed and everything, so the problem is not a partial clog.

As for the extension on the end, it mainly helps the ink flow back into the barrel when tip-up, feeds ink from the cartridge nipple in a cartridge filler or helps position the plunger seal in a vacuum-filler. If you really want to use one in a piston-fill you could probably trim off the extension without too much trouble - Pelikan feeds, after all, have no extension. You might also want to ask around for someone with a feed that already has lost the extension, since they happen.

John