EDC pen prototypes
A few weeks ago I decided I wanted a nice pen that I could keep in my pocket at all times. As an exercise I thought I would design and make one for myself out of aluminum. Well that simple thought has now transitioned into the search for my perfect pen! I've made 3 prototypes so far, each a little closer to the ideal than the last.
The first pen is relatively similar to something you could go and buy at a normal store. Unfortunately these familiar features are it's failures in my eyes. It has a cap which is easy to lose, it uses unreliable gel-ink cartridges and because of it's too-large diameter it is relatively uncomfortable to hold...
After using the first pen for a few days and cataloguing its shortcomings I decided to have another go at it. The new pen was designed around the 'Inka Travel Pen' cartridge, which is actually a miniature 'space-pen' cartridge, which is reliable and well-tested. The material choice for the pen was the same 6061-T6 aluminum as it is durable and attractive. The dimensions of the pen were able to be better designed because the cartridge was smaller, I tried out a bunch of different pens and then settled on a grip diameter of 0.375" and a barrel diameter of 0.35". I decided to stay with the knurling for the grip as I like the look of it, and it can be made comfortable quite easily by simply sanding off the top sharp edges of the knurl after it's cut.
Rather than a normal cap I decided to go with a 'twist' mechanism. Basically you unscrew the barrel of the pen from the grip a little, and this action retracts the ink cartridge. Some teflon tape on the mechanism threads give it an incredibly smooth and pleasant feel.
This version overall feels pretty good, however it's actually too light! Because it's so light it doesn't have that feel that unconsciously tells you 'quality'. So I decided to make another version using steel, with the grip made of brass for a little contrast:
The most recent version feels much better in the hand. It has a solid feel to it that for some reason seems more comfortable to me. I also quite like the two-tone effect, although the brass is actually a little too clean and 'golden' at the moment. Being too close to gold in colour makes it look a little tacky in my opinion. I'm going to wait a few weeks to see what patina the brass takes on with some time, if it doesn't get dark enough for my taste then I may try using bronze instead.
That's all for now, mainly just wanted to document some of the design work that's gone into this so far.