Just was SBRE Brown's review and it looks like the membrane is doing the job.
It raised a few questions
Do you plan on making the production model post? I'm not much of an artist, but I am a paramedic, so indian ink in a metal pen would be pretty awesome in the field. But it MUST post in order to be usable.
Is it using a #5 or #6 sized JoWo screw in nib unit? Have you tested it with one of the desiderata screw in JoWo dip nib feeds to see if there's space in the cap to allow it? You could just test it by taking a zebra G dip nib, squeezing the base of it with pliers to flatten it out a smidge, and then insert it into the pen with the standard EF nib's feed.
How long does the ink reservoir last, and does the membrane/reservoir ever need replacing? How often are you finding the pen needs cleaning, even with the water system (even my fountain pen friendly iron gall requires cleaning every couple months)
Is there a specific reason the clip makes it a nib-down orientation? Does it have drying out problems if the clip's in a nib-up orientation, or just trying to not block the water filler? If possible, I would prefer a nib up clip setup. with perhaps a friction fit clip that slides over the outside of the pen like a kaweco clip (that said, a kaweco clip might fit. What's the diameter of the cap?)
Hi Honey Badgers.
Regarding the post issue, we did on purpose that the cap does not post for several reasons, we want to keep the back of the body slim to improve the ergonomics for sketching, a bit like a nib holder, also the aluminium in touch with the aluminium will damage the surface and the weight balance is completely ruined for drawing.
But the idea of the pen is to make it a bit like a tool so in a near future we might design a different body with a post system and just buy that part.
The nib is a tuned jowo 5 but didn’t try the zebra nib, good suggestion.
The ink converter is standard and the water deposit lasts for months, the membrane does not need to be changed. The cleaning depends on the use, but so far we don't need to clean the pen unless you leave the pen uncapped. It will be ok to rise the pen with water when recharging the ink.
The clip is on the back for two reasons it improves the flow of the ink when using on a shirt pocket in contact with the heat of he body and to make the water loading easier.
Thanks a lot for all your detailed questions, sure they will help other people.