MTG Mana Counter Set — 6 colors, twin-dial

Six MTG mana / life counters in one bundle — one per colour

(**White / Blue / Black / Red / Green / Colourless**). Each counter

is a small disc with two thumb-twistable dials behind a window: the

**left dial reads tens**, the **right dial reads ones**, range

**00-99**. The mana symbol for the colour is engraved into the top

face in a contrast colour (looks great with AMS).

Originally built for Magic: The Gathering life tracking and

Commander damage, but works for any board / card / RPG game where

you need a clicky 00-99 mechanical counter.

## What's in the bundle

- 6 × `half_combined.stl` — one per colour (W U B R G C). Each is the

  full half-shell + its mana symbol pre-aligned in one file.

- 2 × `dial_combined_*.stl` — left dial + right dial. Same two dials

  go inside every counter regardless of colour.

- `mana_counter.scad` — parametric source if you want to retune

  clearances, change disc size, or add a custom symbol.

Per counter you print **2 halves of the colour you want + 1 left

dial + 1 right dial = 4 parts**.

## How it goes together (per counter)

1. **Place a left dial and a right dial** on a flat surface, digit

   faces up. The two dials are mirror-pair, so the digit ring on

   each one is oriented to read upright through its own window.

2. **Drop one half-shell** on top of the dials, mana-symbol side up.

   The dials seat into recessed cavities on the half's inside face.

3. **Flip a second copy of the same half-shell** 180° around its

   horizontal axis (mana symbol now points down) and place it on

   top of the first. The clamp post and bore on the two halves are

   intentionally on **opposite X positions**, so flipping one half

   lines them up.

4. **Press the two halves together by hand.** A 0.25 mm diametral

   interference + a four-slit slotted bore lets the clamp ridge pop

   past the bore body with a firm push and a faint click, then the

   ridge is trapped in the pocket above. **Permanent assembly — do

   not over-tighten in a vise; press by hand.** Once snapped, the

   halves can't separate but the dials inside spin freely.

5. **Twist a dial** by grabbing its exposed rim. About a third of

   each dial's circumference protrudes past the disc boundary so

   your thumb can engage it directly — no stylus needed.

Repeat for each colour you want from the bundle. The two dials are

the same across colours, so for the full set you need **6 left

dials + 6 right dials + 6 pairs of half-shells**.

## Two-colour print (Bambu Studio + AMS)

Each `*_combined.stl` is an ASCII STL with **two named solids in one

coordinate frame** — the body / wheel as one solid, the symbol /

digits as the other. Recipe:

1. Import a combined STL in Bambu Studio (e.g. `w/half_combined.stl`).

2. Right-click on the imported model → **"Split to Parts"**.

3. The two solids become two sub-objects, *positions intact*.

4. Assign filament A (body / structural colour) to the body or wheel

   sub-part. Assign filament B (accent / contrast) to the symbol or

   numbers sub-part.

5. Repeat for every combined STL you want to print.

The mana symbols already use the canonical WUBRG colour scheme but

the print is parametric — paint them whatever suits your taste.

> Why combined STLs? Bambu's "Add Part" workflow re-arranges

> coordinates, which would put the mana symbol off-centre. Single

> ASCII STL with two named solids + Split-to-Parts preserves

> alignment exactly. (Background in this repo's CLAUDE.md under

> "Multi-Color (Bambu Studio AMS)".)

## Single-colour print (no AMS)

Works fine — Split-to-Parts is optional. Print the combined STL as a

single object in any one colour and the symbols / digits show up as

crisp **engraved recesses** instead of inlays. Still very legible,

just less colourful.

## Print settings

- Bambu Lab P2S or any 0.4 mm FDM

- 0.2 mm layer height, 3 walls, 15-20 % infill

- PLA Basic — works perfectly. PETG also fine.

- **No supports.** All overhangs are ≤ 45° including the clamp post.

- Halves print **mana-symbol-face DOWN** on the bed so the engraved

  symbol is the first layer (best surface) and the inside features

  build up cleanly.

- Dials print **flat on bed**, either face down — the digit recesses

  are symmetric.

## Tuning

The default clamp interference is 0.25 mm diametral — "permanent

but pushable by hand". If your printer is over-extruding, the

halves may not seat fully; back off `post_ridge_d` from 10.65 down

to 10.55 in the .scad and reslice. If they feel loose, push the

ridge up to 10.75. The `snap_fit_post_and_slotted_bore.md` research

in the source repo has more on the technique.

## Source

Full parametric `.scad` is included in the download. Variables at

the top control disc size, clamp interference, mana symbol scale,

dial diameter, digit font, and number relief depth. Re-export any

half with a different colour via:

```

openscad -D 'mana_sym="w"' -D 'part="half_body"' -o w/half_body.stl mana_counter.scad

```

Fan content for **Magic: The Gathering** — not affiliated with

Wizards of the Coast.