Skookum Pilot Pen

I was testing out marci10441's Lever Actuated Pen, (which is a remix of blackdynamics' Mechanical Linkage Pen) but the space for the ink refill wasn't big enough for the PILOT BRFV-10EF Ballpoint Pen Refill 0.5 that I had available. So I modified it a bit, and decided, as long as I was doing that, I might as well make some other changes inspired by the Sakura SumoGrip pencil.

The thing name Skookum is an homage to additions that were inspired by the SumoGrip.
Demo and assembly video, https://youtu.be/RjXzGq3J_mY

There are several versions of this thing:

• the simple version without stamps
  • Slim clip
  • Shield clip
• the simple version with stamps
  • Slim clip
  • Shield clip
• the multicolor version with stamps
  • Slim clip
  • Shield clip

Printing

Things to print for each pen:

• 1 pen body
  • Choose one of the following, items that have multiple *.stl files require a multicolor printer.
    • ShieldClip, Multicolor
      • Skookum_ShieldClip_ColorA.stl
      • Skookum_ShieldClip_ColorB.stl
    • ShieldClip, Single color
      • Skookum_ShieldClip_Single.stl
    • ShieldClip, Single color, no logos stamped
      • Skookum_ShieldClip_Single_NoLogos.stl
    • SlimClip, Multicolor
      • Skookum_SlimClip_ColorA.stl
      • Skookum_SlimClip_ColorB.stl
    • SlimClip, Single color
      • Skookum_SlimClip_Single.stl
    • SlimClip, Single color, no logos stamped
      • Skookum_SlimClip_Single_NoLogos.stl
• 1 piston
  • Skookum_Piston.stl
• 1 conrod
  • Conrod.stl
• 1 lever
  • Handle.stl

The terms "lever" and "handle" will be used interchangeably.

The Conrod.stl and Handle.stl are unmodified from the original thing.

Models are already oriented correctly, so the correct side of each part is lying on the bed. No supports are needed. If you have reliable bed adhesion, then no brim is needed; otherwise, consider slicing with a 5mm brim.

Parts & Tools

Parts:
For all screws, any non-countersunk head will work.

• Ink refill (see intro for store link)
  • x1
• pen spring (4.5mm OD, 18mm length)
  • x1
• M3x12mm or M3x14mm screw
  • x1
• M3x5mm screw (M3x4mm or M3x6mm will also work)
  • x1
• M3x6mm screw
  • x1

Tools:

• Driver for the M3 screws
• Scissors to open the ink refill packaging
• A long, slim object or sharp tweezers if the spring needs to be retrieved from the bore

Assembly

See the video for the assembly demonstration

1. Clear any issues on the pen body, especially edges on the opening, where you can see through to the piston. Remove any print overhangs and burs.
2. Take the ink refill and stick the front tip through the front of the pen. If the metal tip doesn't slide in and out easily, widen that bore of the pen body by inserting something and twisting it.
3. Take the pen spring and pull it across its length to that it's length is stretched to about 3/4th the grip's length.
4. Insert the spring into the pen through the hole at the back.
5. Insert the ink refill
6. Insert the piston into the back of the pen. One side of the pistol is beveled; this side should face the back of the pen.
7. Test the pen tip clearance: Insert an object (such as a hex driver) into the bore of the pistol and pull it down all the way, then release the pistol. If the ink refill gets stuck, the pen tip bore needs to be widened more. If the piston gets stuck halfway down, there's probably debris around the piston's channel.
8. Hold the pen out in front of you, the side with the lever lock and lever hinge bore should face you, and the side with the ink portholes should face away from you. All screws being added will be done on the side facing towards you.
9. Take the conrod, and with the extruded part facing towards the pen, thread the largest screw (the 12-14mm) through the conrod and piston.
   • Make sure the screw stays perpendicular while threading.
   • Tighten until a little firm
   • Then loosen a bit, the hinge should swivel loosely afterwards.
10. Take the handle, and with the extruded part facing towards the pen thread the 6mm screw through the larger of the 2 holes and the bore on the pen body.
    • Same notes as with the last screw.
11. Take the last screw, and thread it though the conrod and handle.
    • Same notes as with previous screws.
    • If using a 6mm screw, ensure the screw isn't threaded so far that it protrudes through the other side.

Test:

Final checklist, things to verify before calling it done:

• [x] Does the handle move freely when not locked?
• [x] Does the piston move freely when the handle is manipulated?
• [x] Does the notch on the handle lock into place on the button?
• [x] Does pressing the button release the handle?
• [x] Does releasing the button have enough spring force to swing the handle into the lever stowage lock and keep it there?
• [x] Can the handle be popped out of the lever stowage lock by pressing it with light-to-moderate force?
• [x] Can the pen write as expected?
• [x] Can I write with moderate force without forcing the pen to release (assuming I don't press the release button)?

Source File

The Blender source file is included, Blender 4.3.2.
It updates very slowly due to all the Boolean geometry operations, so godspeed to anyone looking through it.

Changes

• Reworked bore for fitting a specific ink refill.
• Added bigger body and faux-overmold grip.
• Modified slim clip to match new body.
• Added shield clip.
• Modified release button to take up the full height of the pen and extended the back.
• The release button features graphical elements that suggest an affordance.
• Added portholes to view the ink levels (requires good lighting).
• Moved stamps to the curve of the body to make space for portholes./
• Flattened the piston so it's more rotationally constrained.
• Spring is designed to be in front like a traditional pen, and the piston does not hold on to the ink refill.

License

The license is non-commercial to match the original thing's terms.