Pen Blank Cutting Jig

NEW - 4/12/2026: I have included REVERSE designs of both the short and long variations to accommodate "left side" operation.  If you are more comfortable using it in this configuration, or your saw is better set up for it,  you might find these more useful.  The only caveat is to make sure your runner board is long enough to reach your miter slot, which are still typically on the right hand side.

Cut accurate and predictable pen blanks with this one simple trick that craft show pen-turning grandfathers don't want you to know about!  Okay, maybe you fit that description too.  I hope you enjoy this tool as well!

I modeled this handy jig to create repeatable and accurate pen blank cuts that match a brass tube reference and minimize waste. There are two versions.  The “short” base and fence will allow you to pretty much cut most pen blanks, except for things like seam ripper kits (Hi, Bob from RMS!) and possibly some other longer varieties.  It has a working range up to about 3 1/8".  The “long” base and fence will get you to about 4 1/8".  Both work identically otherwise.  There are also two stop blocks.  There's no particular reason why you would want the deep stop block, I left that in during the prototype in case you want to frequently change your offset.  If that is the case, substitute the flat head screw and nut with a second ¼-20 hex bolt and a star knob.  This will seldom be a use case.

Printing:

The model can be printed entirely without support except for the oblong hole in the back.  In Bambu, I use Normal/Snug support only on the base part with a “Support/object x/y distance” of 0.45mm for easy removal (Yes, I know I'm committing a minor sin by mixing units in this explanation, sorry).  If you are using Bambu, I have included a .3mf for your convenience with both varieties on a plate of their own.  You can pretty much print this out of whatever rigid filament you want (PLA was fine for me).  I did 4 wall loops with 15% adaptive cubic infill.  It's plenty strong for this purpose, please let me know if you find otherwise.

Hardware Needed (not included):
 

• (1) ¾" Plywood or equivalent, bandsaw dependent size (ideally a scrap you can't find anything else to do with)

• (1) miter slot runner - this can be your choosing and situation-dependent.  You can use hardwood, an upside-down shallow t-slot, or an actual miter bar slot.  I find it to be a good use of small t-slot cutoffs I can't use in other projects.  You will probably want to drill a second hole as your scrap likely only has one in a small length.

• (4) #10 Pan Head wood screws or equivalent, recommend at least 5/8" length, I used ¾"

• (1) ¼-20 thread hex bolt, 1 ½" long

• (1) ¼-20 pan head screw, 1 ½" long for deep stopblock, 1 ¼" should work for shallow stopblock.

• (2) ¼" flat washers

• (2) ¼-20 hex nut

• OPTIONAL: (1) small ¼" t-track knob.  You can use the plastic ones, but I like the rubber outside knobs that Rockler sells.  As an update, I have included a modeled knob.  If you wish to purchase a t-track knob, you will only need 1 of the ¼-20 hex nuts and will save about 5 dollars.

Assembly:

Install your stop block first (after removing support, naturally).  Using a washer in between the screw head and back of the base, push the pan head screw through the oblong hole, add the hex nut into the provided cutout, and push your stop block in place, securing the screw through and into the hex nut.

There's a placeholder for the bottom hex nut of the base modeled in.  This can be easily separated after printing so you can insert the hex bolt in the bottom.  Place the hex bolt in this space and through the bottom.  Place your fence on top, ensuring it seats into the groove in the base and the hex bolt goes through the channel.  Place a washer on the bolt and then the knob of your choosing.  If you have printed the included knob model, you will also have to remove the placeholder from that much like the base.  You're now almost a danger to the notorious pen-turning cartel with your newfound speed and accuracy but proceed.

Mounting: 

First, you will need to set the offset of the jig to 0 temporarily".  Assuring that power is removed from the machine (I think that's probably a no-brainer), insert the blade into the cut space and ensure the edge touches the fence when adjusted in against the stop block.  Utilize your bandsaw fence and lock it down at this distance.  Remove the jig from the machine.

This jig must be mounted to a user-built sled.  As each bandsaw is different in measurement, the instructions to build your specific bandsaw sled are not included.  Cut a piece of wood (recommended ¾" plywood or equivalent) square that fits both the bottom outline of the jig, as well as enough room to utilize your miter sled. Align your cut of wood and make a test cut about halfway down.  Leave it there.  Again, with the power off (in accordance with prophecy), attach the jig to the base, the fence should line up perfectly with your test cut.  The model is drawn to enable the use of #10 pan head screws or equivalent.  Secure the jig to your wood base.  Now install your miter bare on the underside with whatever method you feel appropriate.  I will usually take my miter bar, elevate it in the slot by using two coins, add two drops of super glue (make sure they are small and don't squeeze out, you're just looking to hold them until you add screws).  Spray activator on the underside of the base where it will contact the bar, and then once you're sure, mate the wood base with the miter bar.  Make sure you add screws to make this permanent.  Super glue will not hold and should not be expected to.  If you're using t-track, the screws are #6 and either 5/8 or ¾ will work.

The cover photo is an artist's rendering of what a complete jig looks like mounted in the saw.  Okay, it's just a cameraphone picture, but it's pretty enough to be art!

Operation:

An offset between 0 and ¼" can be set and this will translate into the blank you cut (ie: a 2 inch pen tube with a 1/16" offset will produce a 2 1/16" pen blank.  I recommend you set this to 1/16" after mounting the jig in the interest of minimizing waste and wear and tear on your barrel trimmer (or whatever you use, for the love of kittens, don't use your teeth, though).  Initial testing of 1/8" resulted in a lot of not-nice words at high volumes when using the barrel trimmer.  You know how to use the stop block by now because you installed it, so read on.

Adjusting the jig for your tube size is as simple as loosening the knob on the base, placing your tube in the negative space of the left side, and snugging it up to the stop block.  Once you lock it down, you are ready to run your sled through the bandsaw to produce a cut with little cleanup waste by placing the blank against the right side of the fence and pushing it through.

Future Improvement:

Feedback is always welcome.  Would it be of use to add a small clamp to keep your hands totally out of the way, or is that overkill?  I feel like that would complicate the design and add strength considerations not envisioned.

Updates Since Initial Release:

• Newly modeled knob, save some money!

• Fillets were added to both base models to alleviate some printing pressure on the hard edges (no operational effect)

• .3mf file was cleaned up and objects were named more appropriately

• 4/12/2026 - Moved graphics to be a little more appealing for my own benefit.

• 4/12/2026 - Added reverse variations to accommodate bandsaws where left side operation is desired.

Happy pen turning!