Twist Pen - Hidden Mechanism
This is an iteration of the first twist pen, where I hid all the mechanisms inside the pen body for a very clean look.
Figure 1: Section View of Pen.
Design
Figure 2: Triple Start Square Threads.
Machining
The most challenging part of machining this pen was making the triple start square threads. I machined both the inside and outside threads with a custom single point threading tool. I machined all parts of this pen on my South Bend manual lathe.