Desiderata Vignettte: Wooden Soubriquets
I designed the Soubriquet pen model as a way of dealing with the structural problems I had with some really fantastic material I came across. Unfortunately, at the time of this writing, I still have not yet released that model in that material! I’ve been sorting out the design and trying to discover its secrets because it’s unorthodox and challenging to all of my skills.
Noteworthy things unique to the wooden version of this pen include:
To maintain the slim profile of the Soubriquet as a large pen that doesn’t feel large, the [wooden] barrel sleeve, after accounting for the fixed sizes of the filling mechanism I designed (Pump Piston™ and Kovacs-style screw piston) has only about 1mm for wall thickness. This is evenly split between the non-metal internal sleeve (which holds the threads attaching the barrel to the filling mechanism) and the wood itself.
Thus, the wood is thin, and the internal no-metal sleeve is thin, and they therefore must be machined to a high degree of concentricity to ensure the filling mechanism can fit in the sleeve, and the sleeve in the wood, and the wood not be so thin the sleeve is exposed once the contour is established. The manufacturing of these parts needs to be as delicate as it is precise.
UPDATE: This information is for models produced before September, 2020. Subsequent models will not have a visible ink window. To keep the ink window in the position indicated in the design, the filling mechanism must also carry the cap-barrel threads, and as such, there remains the possibility that if a hard stop is used inside the cap against the grip section, if overtightened, the filling mechanism could be unscrewed with the cap. This is silly, and so the length tolerances of the cap internals, and the grip section and barrel are such that when the filling unit is tightened hard inside the barrel, the following happens:
The cap lip hits the barrel lip, and then upon further tightening, the ebonite cap lip is slightly deformed, allowing the grip section to abut against the hard stop in the cap. This is to provide an airtight seal around the nib. It is imperative the filling mechanism be tightened securely into the barrel, lest you bear the humiliation of dismantling your pen when you take the cap on. The shame will be hot.
Because the cap and barrel lip bear all the compression from capping the pen, the barrel threads (holding the filling mechanism inside the barrel) were moved from the traditional location of directly behind the barrel lip to about 1.25” deeper. The traditional place for the threads naturally weakens the area because the material is thinned, so by moving the required thinning of the material, by threading, far away from the barrel lip–the part of the barrel under the most stress is unthreaded and thus, as strong as it can possibly be, so that even if the barrel cracks (at the only place it would crack, at its thinnest part) the threads would be unaffected, and the pen can still function.
To accommodate the new Kovacs-style screw piston technology I developed, I designed a special filling mechanism for this pen. It bears a passing resemblance to a convertor, but that’s where the comparison stops. Big ink capacity, ebonite turning knob, very fast piston screw, hard stop, and a much more stable feeling than the average convertor.