Hello again Paul,
my head is spinning right now. I've formatted my hard drive and re-installed XP, etc to see if it will help with my issue of not being able to use any of the "reply" buttons. Well the reply buttons are working great for me now so I'm happy.
I got a laugh when you asked what size do I need. I've made one circuit board so far and it can fit on the palm of my hand. I just needed a PWM (pulse width modulation) circuit for a car wiper motor so I can control its speed. It's to make a variable speed rotating welding table. The old Epson 3000 was purchased purely for its reputation for putting down a lot of ink (I didn't know about QTR when I bought it LOL).
Interesting to learn about the modern cartridges with the wide throats and the valves. Yes a hyperdermic needle is one hell of a restriction to ink flow LOL. The valve would be handy, and what I was doing just before installing the cartridge was sucking out the air while the orifice was at the top, then turning it on its side, pulling out the needle, and pushing the cartridge in. A little bit of ink comes out the hole.
Thanks for all that info on how you fill your cartridges, I'm going to document that. I never knew about these ink bases until you told me. I'm learning a lot from you.
Keith.