Pen turning

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Revision as of 18:57, 29 November 2019 by Rdpierce (talk | contribs) (Trimming the Blank)
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Pen turning is a popular hobby. One can use a small lathe to turn pens (fountain, rollerball, or click or twist ballpoint) out of exotic hardwood, or, in some cases, acrylic. Other items of similar construction can be turned, such as mechanical pencils, seam rippers, crochet hooks, and keychains. Manufacturers supply kit parts containing the hardware. These usually are constructed by gluing a metal tube into the wood and turning this in the lathe on a mandrel. PS:One has a small Wen lathe that can do this well, and a collection of tools specific to pen turning.

Please contact Ryan Pierce or Donzell Gordon for information about pen turning, and Donzell for lathe questions and lathe authorization. The pen turning tools do not require special authorization, but authorization on the Wen lathe is required.

Acquiring Materials

Kits for pen turning can be acquired from many suppliers, which include:

The standard for pen turning is a 7 mm mandrel, which PS:One owns. You will need to purchase bushings specific to the type of pen. Bushings can be damaged by turning, sanding, and finishing, so they are considered user-supplied consumables. Watch the diameter of your bushings and try not to damage them when turning.

Kits frequently are classified by tube size. PS:One has hardware to make pens with the following tube sizes:

  • 7 mm
  • 8 mm
  • 3/8 inch
  • 10 mm

Larger sizes are common for some larger fountain pens, and other less common sizes exist as well. Over time, we anticipate PS:One's tooling inventory for pen turning to grow. This tooling is stored in the blue plastic box under the Wen lathe, labeled Pen Turning. Please make sure all pen turning tools are returned to this box!

At present, PS:One only has tooling for "open end" pens, e.g. where the tube extends the entire length of the wood blank. Special tooling that PS:One does not currently own is required to make "closed end" pens.

Pen blanks typically come in sizes of around 3/4" x 3/4" x 5-6" which is suitable for most small pens. Larger fountain pens may need 1" x 1" blanks. Exotic hardwoods are popular, as are various engineered acrylics with color patterns. These can be acquired from the suppliers, above, as well as many other sources such as eBay and Amazon. Several PS:One members use exotic hardwoods in their projects; it may be possible to recycle scrap for pen blanks. One can also laminate woods together to make a multi-layered blank.

Cutting and Drilling the Blank

Most pens consist of two pieces, in which case the kit includes two tubes. First, cut the pen blank to length in one or two pieces, each slightly larger than the length of the respective tube(s). Make a mark on the side of the blank before cutting so you can establish orientation later to match the wood grain. Also, mark the center of each cut pen blank on one of the small ends. (Diagonal lines connecting opposite corners intersect at the center.) Then very loosely clamp the opposite end in a 4-jaw chuck mounted to the lathe headstock. Insert a 1 MT Jacobs chuck in the tailstock, and insert one of the following brad point drills, based on the tube diameter specified in the kit instructions, in the Jacobs chuck. The Jacobs chuck currently hangs on a wall rack near the Wen lathe. Drills are stored inside the blue "Pen Turning" box. These brad point drill bits are designed to bore into the wood without wandering and are substantially more expensive than traditional drill bits. Please use these drills only for pen turning and make sure they are returned to the blue "Pen Turning" toolbox so that they do not get lost in the woodshop. The following drill sizes are available:
  • 7 mm
  • 8 mm
  • 3/8 inch
  • 10 mm

Fully retract the tailstock ram, slide the tailstock so the drill contacts the pen blank, and Lock the tailstock. Push the pen blank onto the brad point of the drill at the marked center point and then tighten the jaws on the headstock. Power on the lathe and crank the tailstock ram to drill into the stock. Once the ram limit is reached, stop the lathe, retract the ram, side the tailstock closer until the drill makes contact with the bottom of the hole, lock the tailstock, and repeat.

Tips: First, use the pen blank to determine the depth that the drill will need to enter the wood and make a mark with tape on the drill bit. Also, a drill emerging from the end grain can tear out wood. Make sure the blank is long enough to account for possible tear out. Masking tape placed over the end grain of the pen blank can help reduce tear out. Also, keep in mind that this is an inexpensive lathe with rather high runout, so expect some difficulty drilling.

Gluing the Tube

After you have drilled the blank, the next step is to glue the metal pen tube inside the hole. Make sure the tube fits without too much force, and that it can be positioned so that excess wood extends beyond both metal ends. If tear out has occurred, take care in positioning the tube so that the area of torn out grain does not contact the tube itself, if possible. You can use 2-part epoxy or CA glue. Sand the outside of the tube if it is not rough already from the factory. Cover with a thin layer of glue. Use the conical insertion tool (stored in the Pen Tools box) to inert the tube into position inside the blank, and let the tube dry.

Trimming the Blanks

The next step is to trim the wood exactly perpendicular to the pen tube, and to the exact length of the tube. At present, we have only one method of blank trimming: a universal pen trimmer. We anticipate getting a disk sanding jig at a future date.

Universal Pen Trimmer

This set consists of a steel 4 blade cutter or a 2 blade carbide cutter. The steel cutter is fairly dull and cuts slowly. The carbide cutter will cut aggressively and is more likely to tear out end grain. One of four inserts goes through the center of this, and is held in place with a set screw tightened using the attached Allen wrench. (The set screw for the carbide cutter appears to use a different sized Allen wrench!) the following inserts are available to square pens with tubes of the following diameters:
  • 7 mm
  • 8 mm
  • 3/8 inch
  • 10 mm

The inserts contain reamers that will also trim dried glue from the inside of the tube. Additionally, the kit includes a brass tube that slips around the 7 mm reamer so it will fit tubes used for the Penn State Industries #PKPARK-PCL and #PKMONT-PCL kits.

It is helpful to secure the pen blank in a vise, or clamp it while trimming, which can help prevent tear-out. Chuck the trimmer in a drill and then trim the wood square and exactly flush with the tube, taking care not to shorten the tube appreciably.

Turning the Body and Cap

The 7 mm pen mandrel comes with 5 spacers, which generally aren’t used and are set aside. The pen mandrel goes in the lathe headstock. One then assembles the bushings (specific to the pen kit, which the user is expected to supply) and the pen blanks with tubes on the lathe according to the kit directions. Take care because the assembly order typically does matter; often, pen caps or upper body parts are different diameters than the lower pen body.

We use a “mandrel saver” that slips on the end of the mandrel and has a Morse taper that fits in the tailstock. Apply enough tension using the tailstock ram so that the piece can be turned in the lathe securely, but avoid excess tension. Make sure both the tailstock is locked to the bed, and the ram is locked in the tailstock. If, when turning, you find that the wood catches on the lathe tool and stops while the mandrel still spins, that indicates inadequate ram pressure.

Then, turn the wood to the appropriate profile, according to the instructions and artistic preference. Keep in mind that the amount of wood on a typical pen may be less than 1 mm. The lathe tools have a tendency to gouge the wood and tear at the grain, so use lathe tools for rough shaping only, and approach the final diameter and profile with course sandpaper.