Next step, preparing the tubing and then "gluing" the tubing inside the pen blank material. Pen mechanisms are designed to work inside some type of housing. Most penmakers use brass tubing to hold these mechanisms inside the material they've chosen for their pen body or barrels. This material can be any of a number of beautiful wood species and colorful resins specifically made for penmaking to more exotic choices like antler, horn, or shredded currency pressure cast in clear resin. The material chosen for the pen body must be able to be machined precisely to accept the brass pen tubing. Close tolerances are required because the inner workings of the pen are secured in the brass tubing by pressure fit. Too large and the brass pen tubing cannot bond well to the pen body material. Too tight and the pressure fit of the brass tubing can crack the pen body material.
I use a dedicated drill press to drill out my pen barrels but many penmakers drill with attachments on their lathes. However it is done the drilling must be centered in the blank and done at speeds appropriate for the material. To ensure the drill bit starts off tracking down the center of a narrow pen blank, I always find the center of the blank and mark it off in pencil. I then dimple the center point with a spring-loaded punch. This gives the drill bit a place to start in proper tracking. Drill speed varies by the material with resins and stabilized wood generally requiring a slow speed to preserve their integrity. A good practice to prevent overheating in any blank material is to continually withdraw the drill bit to clear the chips (swarf) produced by the drill bit. I've never had trouble with what some describe as "blowout" by using this method.
Next step, preparing the tubing and then "gluing" the tubing inside the pen blank material.