Peptide Pen & Tip Holder 6-Pen Grid Version (3x2)

This is a remix of Peptide Pen Needle Holder.

What I changed (vs. the original 3-pen holder):

• Holds 6 pens in a 3x2 grid (3 across, 2 rows) on a 24 mm square pitch.

• Larger pen bores (Ø20.6 mm) so fatter auto-injector pens drop all the way in — fits ConviPen, GensuPen2, and Incepta pens. (The original's bores were too narrow for these.)

• Wider clip slits (10.6 mm) with per-row routing: the front row's slits vent out the front face and the back row's slits vent out the back face, so every pen's clip/window clears as it seats.

• FOUR needle-tip keyhole rails — two per short end, at X = ±13 mm. The keyhole cross-section and its full 4.0 mm pocket depth are copied 1:1 from the original; the body's ends are sized so the rails clear the corner pen bores (and their rim chamfers) with real margin. Throat 14.2 mm < tip flange 15.5 mm < chamber 18.7 mm — the same disposable tips (e.g. 32G×4 mm) clip in and stack.

Body: 80 × 48.6 × 90 mm — a compact block: 3.4 mm webs between bores, 2.0 mm front/back walls (short slit tunnels), ~1.7 mm between each rail chamber and its corner bore. Print upright (bores facing up), no supports needed.

Fully parametric. It's an OpenSCAD model — if your pens differ you can change a single number and regenerate. The .scad source, a validate.py geometry checker, and a one-shot render.shbuild script are included.

Tuning knobs (edit in pen-holder.scad, then regenerate):

• pen_d — widest body diameter of your pen (bore = pen_d + drop_clearance).

• drop_clearance — drop-in fit clearance (default 0.5 mm; bump to 0.6 if snug).

• cols_y / rows_x — pen count in the grid (default 3 × 2).

• pitch — grid spacing (default 24.0 mm square; web = pitch − 20.6).

• slit_w — clip slit width (default 10.6 mm; set to your clip's width).

• end_margin_y — end-wall / rail-clearance lever: +1 mm here adds +1 mm to the end wall and the rail-to-bore margin, and grows the body by +2 mm in Y (default 16.0). Compile-time asserts stop you if rails would hit a bore or its rim flare.

• rail_total_y — rail pocket depth (default 4.0 mm = full original profile; shrink it if you shorten the body).

• rail_x— rail positions along the end faces (default ±13 mm).