Having learned a couple of things after making the prototype, I made this pen the following weekend.
The first step was to make a new brass coupler. In order to accommodate the curve of the pen, it was necessary to make an entire cap with a stepped diameter, since a straight tube resulted in the wood being too thin and therefore weak at the top of the cap. The barrel side was also re-designed with a stepped diameter for the same reason.
The pen is initially turned on the lathe to create the desired concave curve (the bottom of the drawing shown below). Note the hole in the top of the cap insert to allow air to escape when inserting it into the wood. This has to be sealed afterwards with epoxy to prevent the nib from drying out later…
When the turning is done, the pen looks like this:
It’s then sanded on the disc sander to make the “sides” parallel and the “back” perpendicular (at least, to start…).
The convex curve can then be drawn on the flat sides and this shape is sanded slowly and carefully – while repeatedly checking against the template to make sure that I don’t break through to the interior…
Finally the pen is rounded initially using the disc sander and then sanding by hand. This takes some time – but it’s less dangerous because the further (in rotation) I am from the convex curve, the more wood I have between the exterior of the pen and the hollowed interior.
Note that the brass coupler was epoxied into the olive wood with the intention to have the barrel of the pen curve over the back of my thumb when I’m writing. This was a mistake in the prototype, where the relative rotation of the nib and barrel were random.
The pen was finished by carving a matching crib, made from the same piece of olive wood.
I may update the design sometime in the future by increasing the taper at the end of the barrel by bringing the convex curve in a little tighter. The only problem with this is that it would mean that I could not drill as deeply, and therefore I would be stuck with using short ink cartridges instead of using a converter. Another option would be to make the taper by reducing the concave curve, but I have a feeling that this would result in a pen that’s too straight.
Total weight: 40.6 g
Body weight: 25.2 g
Total length (not posted): 149 mm
Total length(with cap): 175 mm
Barrel max diameter: 14.4 mm
Cap max diameter: 16.6 mm