MACHINE PEN, EASY 4 PARTS

03/24/26 edit: Added profile with folding tripod.  Link to the case for both pen and tripod at the bottom of this description.

03/20/26 edit: The neck is now 4 layer loops thick, instead of just 3.  The 7 old profiles have been condensed into 3 new.  A link to the case has been added to the bottom of this description.

Thanks for checking out this NEW pen design.  Please give it a “THUMPS UP!”

These pens have a very simple construction.  They are fidgety and click with a lot of force, so very satisfying.   Only 3 printed parts, and 1 ink-core and 1 spring.  

How it works: Push the top button to engage the pen, and press on the ridges to disengage. 

TEXT can be changed in the Bambu Slicer Software.  Just double click text and a dialog box will open up to make changes. 

Parts needed: Printed parts, 1 ink-core, and 1 spring from 1 of these pens.

• Pilot G2 pen. (Best)
• Mr. Pen
• Amazon Basics Gel Pens, retractable
• Pentel EnerGel 

• For Sharpie S-Gel you will need to cut .08-inch [2mm] off the back of the ink-core.

Print Settings: (Already set in the profiles)

• High Quality 0.16 Layer height, 2 walls, 13% gyroid infill.
• Add Height-range-modifier to slow the top of the print to 20mm/s.  Range 117 - 126.5 mm.
• You may want to add a brim to the main housing.  Profiles have them, but I have printed many without brims, and had no problems
• Filaments tested Successfully:  PLA Basic/Matte/Silk, ABS, Petg HF. 

After Printing:

Remove the support and inner/outer brim material : (use a tool or strong fingernail.)

Before:

After:

Assembly:

1.  Remove ink-core and spring from one store-bought pen, listed above in “Parts Needed.”

2.  Insert ink-core into button part.

3. Insert the ink-core/spring/button assembly into the pen housing.  See 2nd pic below for alignment.

4.  Press the clip on the back, and your DONE.

To Assemble the folding tripod, press these parts together.  

End of Assembly instructions:

Trouble shooting issues: (please let me know in the comments if you run into any.)

1. If the tip of the ink-core does not retract, then the hole for it may have printed too small.  To fix, leave the pen assembled, but retract the pen tip by pushing on tip with something while pressing the retract button/ridges.  Then use the tip of another pen to open the hole up a little.  Just press the tip in the hole and wiggle it about.

    

If needed, To Take Apart: (not easy, I've broken a few trying.)

1. Push up on the clip. Then remove the clip

2. Push a sharp object to disengage 1 and 2.  Then pull the button out.

3.  Then pull button out, and dump the ink-core and spring out of the housing.

----------------Link to other designs------------------------------------------------

Here is a link to the two styles cases for this pen.