Parametric Rosette Coin & Fridge Magnet - No Text, 3 Presets

A challenge-coin-inspired souvenir with a raised rim, two-layer star rosette, center boss and reeded edge. No names, dates, logos or fonts: customize the shape through diameter, rim width, point count and edge reeds.

Choose a preset

• coin40.stl: nominal 40 mm diameter, 2.4 mm body, 4.00 mm overall height, 8-point rosette, 48 reeds, 2.2 mm rim.

• medallion50.stl: nominal 50 mm diameter, 3.0 mm body, 4.60 mm overall height, 12-point rosette, 60 reeds, 2.8 mm rim.

• magnet50.stl: nominal 50 mm diameter, 2.4 mm front body, 6.25 mm overall height, 10-point rosette, 60 reeds, 2.8 mm rim. Rear pocket: nominal 10.4 mm diameter x 2.25 mm deep, intended as an untested glue-fit starting point for a 10 x 2 mm disc magnet. The 32-sided opening is about 10.35 mm across flats.

The actual X/Z bounds are 39.973 mm and 49.979 mm because the reeded outline is faceted.

Important limitations

These are CAD-verified models, not physically tested prints. Every connected shell is watertight, consistently wound and positive-volume, with zero degenerate triangles. They remain overlapping closed shells, not a Boolean-unioned solid. Your slicer must combine the overlaps correctly. Coin40 and medallion50 have 5 shells each; magnet50 has 6.

Do not split the STL into separate print jobs. Keep it assembled and check layer preview at every overlap and relief transition. Watertight-shell checks do not prove slicer compatibility or a successful print.

Orientation and print starting points

• Numeric dimensions are intended as millimeters; STL is unitless.

• Export is Y-up. Rotate +90 degrees around X to put the rear down and decoration up. Confirm the orientation and dimensions before slicing.

• For the flat-back coin and medallion, suggested starting settings are a 0.4 mm nozzle, 0.2 mm layers and 3 walls, with enough solid top/bottom layers for the shallow body. These settings are not print-tested.

• Magnet50 rear-down needs a roughly 10.4 mm ceiling bridge or removable local support. Inspect the bridge and make sure support can be removed through the rear opening.

• Test physical pocket fit and glue the magnet after printing. Magnet retention and holding strength have not been tested.

Keep loose magnets away from children. This is a decorative experiment, not a toy or a load-rated mounting part. The gold images are renders of the actual exported STL triangles, not printed samples. Their colors are illustrative; no multi-material print profile is included.

Customization and native recipe

The files include three literal TrueGeometry Playground recipes and medallion_recipe.py. The Python file is a command expander, not a mesh generator: it writes native commands that build the model in Playground.

Customize diameter, body thickness, rim width, rosette points, reed count, relief height and rear pocket diameter/depth. Set pocket diameter to 0 to disable the magnet variant. See README for accepted input bounds and examples. Only the three included presets have been tested live; other combinations need their own CAD, mesh and slicer checks.

Open https://www.truegeometry.com/CoreWebGLTG/KBEAgentHTTP.html, start with an empty scene, open Script and run one complete recipe. Wait for Script Completed, then export the whole model with /export_stl all. Save the recipe because the browser scene is temporary.

The native method uses /sm_part for the body and stars and /revolve for closed annuli. Layers overlap by 0.15 mm. No text, imported geometry, 3D Boolean cuts or unions were used. Recipe files are supplied separately so the full coordinate commands remain available without making the listing difficult to read.

Files to include

• coin40.stl, medallion50.stl, magnet50.stl

• coin40_recipe.txt, medallion50_recipe.txt, magnet50_recipe.txt

• medallion_recipe.py.txt, README.md and the How-to-Run-a-Script PDF

Full TrueGeometry Playground commands: in the blog article https://blog.truegeometry.com/0_0_0_0/blogs/post-d5f2b99e.html and the attached recipe files.

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