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Pen Kit Tooling
A guide to understanding the tools needed to
make wooden pens.
All about the drill bits, mandrels, and bushings you need
to make top quality Pens.
Tooling is the term used to refer to the reusable supplies
you need to make wooden pens. The tooling generally includes the drill
bit, mandrel, and bushings. The following article details what you need
and what to look for when selecting tooling for your pen making projects.
Drill Bits
Drill bits are used to bore a hole in the center of a wood
blank. Copper tubes are then mounted glued into this hole and the pen
assembly is mounted on a mandrel in the lathe. Selecting the proper drill
bit is critical for an exact fit between the copper tubes and the wood. It
is also important to use a drill bit that will drill straight and not
wander - and risk ruining the pen blank.
The pen turning bits we recommend and sell at WoodZone are
called Parabolic flute drill bits. They have a 135-degree split tip and are
designed to drill through end grain wood, plastics, Dymondwood™, Corian™
and other materials far faster and with less cracking than any other drill
bit. These are true industrial-quality and will last for up to 500
drilling cycles.
So what makes these drills so special? The parabolic flute
is used to long bore drill aluminum in industry. And you won't find these
bits at your local hardware store. The flute pattern quickly lifts and
blows the chips out of the hole and this reduces friction and pressure.
The tip of the bit is ground to a 135 degree "included angle"
which, along with a split tip, allows the drill to cut its own pilot hole.
This means the drill enters the material straight and stays straight -
preventing drill deflection. They are the same drills that are
widely used in the space and aircraft industry.
Important tip: These drills should be run between 900 and
1500 rpm. Slow is bad as it can cause burning and poor finished holes.
Drill Bit Sizes
All the parts and tubes for pen kits are made to metric
standards. For the most part the inside and outside diameters of the tubes
are not metric numbers. For example, the small cross or "7mm"
pen kit's tube is 6.8 mm in OD and 6.3 mm in ID.
A standard drill set is composed of drills sized by
numbers (1-80) fractions (1/64 thru 1/2") and letters (A-Z). When we
choose a drill bit to use with a kit we test all drill bit that are
slightly over the actual OD of the pen kit tube. We choose the one that
gets the best results taking into account that the hole will close up a
bit after drilling, wood thickness, clearance for glue etc.
Mandrels
A mandrel is a straight steel shaft that allows you to
mount and turn the pen blanks on your lathe. One end of the mandrel has a
nut and a centering hole. The other end goes into the lathe's headstock.
To hold the shaft in your lathe, you must have either a drill chuck or one
of the specially made tapered arbors that fits in the headstock spindle.
The tapered arbors are available in #1 or #2 Morse taper. To determine
which one to use, consult your lathe's instruction manual or visit the
manufacture's website. #2 Morse taper is the most common size.
The end of the mandrel with the nut and center hole
receives the point of your live tailstock center and supports the shaft.
Your tailstock should be tightened into the mandrel very gently to avoid
flexing or bending it.
We use two sizes of mandrel for our pen kits: A and B. The
"A shaft" is about 1/4" in diameter and the "B
shaft" is thicker (about 0.921"). We use the "B shaft"
for some of the larger kits as it gives better support with "less
whip" and therefore a more accurate pen.
Bushings
Bushings are the essential guides that show you how far to
turn the wood down so it matches the mating pen parts. The bushings are
round steel pieces with a hole in the center for the shaft. The
instructions that come with the kit show how they are slid onto the
mandrel shaft. On our website the correct bushing set is listed with the
pen kit. The letter after the bushing number indicates the shaft size it
fits onto (A or B).
Conclusion
Pen kit tooling is essential to making quality writing instruments. At
first all of the options available can be a bit intimidating. Hopefully
this article has cleared up much of the confusion. If you have any
questions about pen kit tooling please email us at woodmaster@woodzone.com
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