The second thing is that there are bushings that determines the final diameter of the barrel, so you want to know those bushing size before you get started turning. The right size bushing ensures that the body balance with the cap. If you don’t have the right one then it will throw the balance and make the pen look like it was made by hand (which may not be what you were going for).
This chart shows comparison between various pen style so you can match your kit up with the right bushing, drill, tube, and mandrel. The nice thing about European (or slimline) kits is that they are forgiving hardware-wise. That means even if you don’t have the greatest of luck using this type of equipment, you’ll still end up with a finished pen that looks polished.
How to Choose Pen Parts and Blank Sizes
These kit use a 7 mm drill bit and run on a 7 mm mandrel. The bushings determine the final barrel size and make it possible for the trim rings to fit flush. If you stick to those combinations, your pen will come off the lathe, ready to be assembled. No need for any additional sanding or shimming here.
This also holds true for the larger styles. Because the barrel is larger, cigar and bolt-action pens takes a wider blank, and a 10 mm mandrel runs them. If you try to turn one of these larger style on a smaller mandrel, then the bushings won’t fit snugly, making the turning inaccurate.
So why do I like it? Because it’s not about memorizing all of the measurements, but rather knowing what each number means. That way you know what size drill bit to buy based off the OD of the tube. You know how thick your completed barrel is going to be based on the OD of the bushing. You know which bushings will slide on the mandrel by looking at the size of the mandrel.
Now that you understand those three relationships, picking the correct kit are like following a checklist. It is not guesswork anymore; you have a process for each kit.
Many people think that all slim-style pens uses the same mandrel, which is 7 mm. That’s not true in practice. A European kit use the same-sized mandrel, but requires a slightly bigger drill bit and different sized bushings, because it has a wider tube. If you swap pieces across kits without accounting for their relationship you’ll end up with barrels that don’t fit your hardware; they will either be too fat or too thin.
With the chart above, you can see the difference at a glance. You can catch the mismatch before you put glue on your wood so you’re not wasting materials.
Blank size also is another detail often overlooked. To turn a slimline blank, all it takes is a piece barely wider than three-quarters of an inch. For a cigar blank where you have some wiggle room in the final shape, nearly an inch and a half is what it take. If your blank is too small you are going to have to take material away later on. And when you get there you’ll want that wood back to create the shape of the grip or the transition between the butt and the cap.
The finishing process is brief and starts with turning, then sanding with increasingly fine grits until you are ready to polish (with a friction polish or thin coat of CA). Skipped grits leaves scratch marks that becomes visible once the pen is reassembled and sitting on your desk under normal light. Same goes for the drilling. Use a twist bit and there will be a messier hole than if you used a brad-point bit. Drill oversized for the glue gap by a hair so the tube doesn’t bind when inserted.
Pen turning is fast from blank to finished product when all the pieces come together. The chart above means you don’t have to figure it out every time you open a new kit. It should of saved you time by having things clearly spelled out from the beginning.
