i did it first!lol
there is an internal screen in the stems themselves as well, they can also be used without the capsule.
did grind the flowers, some fine particles come through, the holes are rather big on the capsules. should be good with a medium to coarse grind even without the screen in the stem.
given my limited experience (4stems) i had no problem with the glass insert until now. i use the highest quality boro silicate glass tubes for my stuff, schott duran. i think one of the key features is that they are tight within specs! i havent had my stems long enough tho to see whats happening after some time.
yes wooden stems fit the glass joints very snug, also if they dont, not all is lost in an instant.
now, we only need them bent wooden stems...
@Alan are you a wood bender?
today at the lasercutter, it had to be done: