Hi fountain pen friends !
I could not resist , and decided to design and make a MB149 size streamline ” Porthole GF piston filler”
I’ve used my very last Tibaldi Impero for this pen, just 2 cm of the celluloid was left when the parts were finished.
The section is 21mm long, and the length of the front of the section to the barrel diameter transition is 31mm .
Doing so so one does not feel any ergonomic drawback from the diameter transition during writing.
There are again 4 portholes - 180° apart - and given the 4 leads thread, this makes that the portholes are always perfectly aligned with the nib and clip.
Note the portholes are somewhat condensed after I’ve tested and flushed the pen, but they are crystal clear !
The cap shape is only slightly convex, limited by to the wide "wing width" of the vintage MB149 nib I wanted to install, which implies the need for a larger inner bore of the cap..
I’ve used my standard ball clip, and made the ball resting on the silver ring, avoiding possible contact damage on the celluloid.
As always your comments and critiques are most welcome !
Best regards from Flanders,
Francis
