I have a Micron head core (no nozzle, air cap) that has a scratch from long ago, thankfully I have the iwata pliers now, but I'd be willing to trade that core to one of you tinkerers here, for perhaps a space needle, and o-ring
I had a thought though for the modders here, I was thinking about how to improve the inner surface of the nozzle. Two thoughts came to mind, using diamond paste on an old needle to lap the inside of the nozzle. I used to have a gunsmithing hobby. They have lapping compounds to smooth out the finest abrasions in the bore of a barrel. Even one guy invented lapping bullets you can reload, and just shoot them thru, the lazy way. The regular way is with a cleaning rod and working it up and down the bore. That's why I was thinking diamond paste on a needle spun by a drill. Or the other option is creating a lapping needle. Instead of the quest for the smoothest needle, instead purposely create a needle that has a micro abrasive surface. Granted we're talking some extreme delicate work, as the nozzles are already so damn thin, and obviously not steel like a gun barrel that can take some abuse. These may be awful ideas, or good ones idk. But if we had a smoother surface inside the nozzle, we might be able to lower the surface tension threshold of the paint, allowing a smoother transition from no paint, just tip dry, to fine lines. Has anyone managed to have access to imaging equipment that can look inside a nozzle? I might, if I go to the engineering department of my school, the third largest in my state.