Make a Record Test Disc: 120 mm FDM and Laser Presets

By the Make a Record project · Software reference v0.1.0

Make a small trial before committing to a full-size record. The experimental testfdm120 and testlaser120 presets generate 120 mm discs at 45 RPM for short WAV or MP3 excerpts. Neither has a validated physical playback result yet.

Choose FDM or laser

FDM: testfdm120 produces an STL with the same groove pitch, width, depth, and lateral amplitude as the 0.4 mm bambu04 preset. Its smaller disc reduces material use, but the groove still needs careful slicing. Print flat with the grooves up using an installed 0.4 mm nozzle.

Laser: testlaser120 produces DXF using the lightburn7 groove geometry, with a smaller disc and a narrow program band. Select SVG in the converter if your software requires it. Import in millimetres, verify the 120 mm outline, and assign the groove and full-depth outline cuts to their appropriate operations. See the laser guide for kerf and layer handling.

Use a repeatable 5–10 second excerpt

1. Choose a WAV or MP3 you recorded or have permission to use. A short spoken phrase provides an easy reference for intelligibility.
2. Select a test preset. Set Start at to your excerpt's beginning and Length to 5–10 seconds. The preset selects geometry; it does not automatically set a ten-second excerpt.
3. Generate the files and save the report. Listen to the generated preview to confirm the selection.
4. Inspect the slice or laser paths and fabricate one test. For laser work, measure kerf on the intended material and adjust geometry before making the record.
5. Check the finished surface and record turntable playback at 45 RPM. Change one setting at a time for the next attempt.

Check the arm before using a small disc

A 120 mm disc is smaller than a standard 7-inch record. Automatic cueing may miss it, and an auto-return mechanism may stop playback before the groove finishes. Check the turntable's manual and tonearm travel first. If it cannot play this diameter, use a larger preset with the same short excerpt.

What should I save from each attempt?

Keep the original audio, generated preview, and actual playback recording as three separate files. Record the preset and overrides, machine, nozzle or optics, material, slicer/controller settings, cartridge, and RPM. Photograph the disc and groove. A successful import or clean preview is not evidence of physical playback.

Does a successful test prove a larger record will work?

It provides evidence for the tested settings and section of groove. A larger disc changes the linear speed, build time, and potential for warping. Repeat the short test on the intended final diameter before using the full capacity. The table below reports geometric capacity; the converter may use less when the source or selected excerpt is shorter.

Current preset geometry

Values below come from the converter's presets. Capacity is a geometric maximum, before the web app's point limit or a shorter uploaded clip is applied.

Method and further reading

This guide describes Make a Record's source code and presets. The broader technique follows earlier digital fabrication experiments, including Amanda Ghassaei's laser-cut records. Suggested fabrication settings need validation on your machine; they are not manufacturer-certified profiles.