I bought some Bock nib units on eBay which appear to be designed to use in non-cartridge pens (such as eye-dropper, piston, or sac) as they have no rear nipple for a cartridge/converter to slide onto. I've built a couple of pens for these nibs so far, and both have the same problem: too much ink flow, with the result that I get a puddle of ink if I don't keep writing at top speed. Right now I've got an eyedropper loaded with Noodler's Red Fox (ink which works well in my cartridge/converter pens) but the feed runs way too fast in this pen. Is there a recommended way to slow down the feed? Is there a better choice of ink to use with this "fast feed" nib unit? Thanks for any guidance.