The Ultimate Parametric Keycap Generator

The Ultimate Parametric Keycap Generator

The Ultimate Parametric Keycap Generator is a complete ecosystem designed to create professional-grade mechanical keycaps, perfectly calibrated for your specific printer and material. By using the included calibration tools, you can eliminate fitting issues and misalignments, achieving a factory-quality feel on your first print.

 

Please feel free to contact me in the comments or via private message for any kind of questions. I am always happy to help you fine-tune your settings and get the best results!

🚀 Key Features

• Full Parametric Control: Every aspect of the geometry is adjustable via the Customizer.
• Square & Round (Typewriter) Styles: Choose between the classic square profile or a "Typewriter" inspired round style.
• International Layouts (BETA): Native support for US, IT, DE, FR, ES, UK, PT, Nordic, and CH layouts.
  • Note on Accuracy: These layouts were verified using external references (Wikipedia). 3 As I am an Italian maker, I cannot guarantee 100% accuracy for every region. Please leave a comment if you find any errors or have suggestions for improvements!
• Custom Multi-Legends & Emojis: Create unique keys using text, symbols, and emojis. Use the | symbol to stack up to three different legends on a single cap (e.g., "A|B|C" or "!|1").
• ISO-Enter Available: Full support for the ISO-Enter key format.
• Fully Customizable Length: Adjustable key length (up to 7.0u) to fit Shift, Spacebar, and other special keys.

🧪 Calibration Workflow (3-Step Process)

For the best results, follow this workflow using the provided .3mf files for Bambu Studio or the dedicated SCAD scripts:

 

Step 1: Stem Fit Test

• File: Use the .3mf calibration file corresponding to your chosen nozzle size (0.2mm or 0.4mm). Each plate in the .3mf file includes test keys for both Square and Round styles. I recommend selecting and printing only the test keys for the specific style you intend to use to save time and material. Alternatively, you can use the Customizer for Keycap_Fit_Calibration_Tool.scad.
• Goal: Find the perfect cross-slot tolerance for your specific switch, printer, and material.
• Reading Results: Download the file and print Plate 1. On each test key, the top engraved number represents the Vertical slot width, while the bottom number represents the Horizontal slot width (e.g., 1.30 | 1.40).
• Action: Test the printed keys on your switches. Select the one that fits snugly and note down these specific values for the final generation step.
• Note: If none of the provided test keys satisfy your requirements, simply use the Customizer to generate a personalized configuration with your own set of values.

Step 2: Y-Offset Alignment

• File: Continue using the same .3mf file from Step 1, but ensure you select the specific Plate that corresponds to the "Fit" result you identified in the previous step. Each plate in the .3mf file includes test keys for both Square and Round styles. I recommend selecting and printing only the test keys for the specific style you intend to use to save time and material. Alternatively, you can use the customizer for Keycap_Offset_Calibration_Tool.scad.
• Goal: Align the keycap shell perfectly with your keyboard frame.
• The 180° Trick: The test keys demonstrate positive offsets ranging from 0.25 mm to 1.00 mm. If your keyboard requires a negative offset, simply rotate the printed test key 180 degrees on the switch to test that same value in the negative direction—just remember to use the negative value in the final customizer.
• Note: If you are planning to replace the entire set of keycaps on your keyboard, fine-tuning the offset might be superfluous, as the alignment will be consistent across all new keys. This calibration is most important when matching a single custom keycap near to the original ones.

⚠️ Important: While printing your calibration files, pay close attention to the quality of the legends. If you notice issues like the base color bleeding through—especially with light-colored legends—please refer to the 'Legend Quality & Advanced Exporting' section below to learn how to export components separately for the best possible results.

Step 3: Final Generation

• Files: Click “Customize” and use the square_suggested_parameters.scad or round_suggested_parameters.scad generators.
• Action: Input your calibrated values (vertical slot width, horizontal slot width,  and stem offset y) in the “Stem & Switch details” section into the Customizer to generate your perfect keycap set.
• Layout Selection:
  • Select a specific language to use pre-set international layouts .
  • Select "Custom" to enable the custom_keys_string field for your own text and symbols.
  • Select "Empty" to generate a blank keycap for further customization in your slicer. This is the best option if you want to add custom logos directly in your slicer. In Bambu Studio or OrcaSlicer, simply right-click the model, select "Add Modifier" -> "SVG" to import any graphic (like icons from SVG Repo).
• Font Family:
  • Use "Liberation Sans" or "Noto Sans" for standard alphanumeric text.
  • Use “Noto Emoji” for emojis 😀😝😱😘💀👁︎☎︎🧀 and many, many more (here all the available emojis).
  • Use "Noto Sans Symbols" (here all the available) or "Noto Sans Symbols 2" 🡨🡩🡪🡫 🡬🡮↵⏎(here all the available) for special graphic symbols like arrows, play/pause buttons, and thousands of other icons.
  • Use "Noto Sans TC" (here all the available) to correctly render Chinese characters
• Local SVG Feature: The "Local SVG" option is only available for offline use by downloading the SCAD file to your PC. I plan to make this project open-source if it achieves success within the community.

I recommend scrolling through all available options to better understand the vast customization possibilities of this tool. Every setting includes a comment explaining its specific function. I realize there are many options, but that is the price to pay for a truly powerful and professional customizer.

📐 Technical Documentation

To understand how each variable affects the geometry—such as d_top, total_height, or wall_thickness—refer to the Dimension Reference Sheet provided as a PDF. This technical blueprint maps every OpenSCAD variable to its physical location on the keycap.

💬 Leave a comment!

I would love to hear about your results! Please leave a comment sharing your experience and the specific values you discovered during your calibration (Vertical/Horizontal slot widths and Stem Offset) . Including your printer model and the material used (PLA, PETG, ABS, etc.) helps other makers achieve perfect results even faster.

As the international layouts are currently in BETA, your feedback is especially important . If you find any errors or have suggestions for improvements, please let me know so I can refine this generator for everyone!

🎨 Legend Quality & Advanced Exporting

While printing your calibration files, pay close attention to the quality of the legends. If you notice issues like the base color bleeding through—especially with light-colored legends on a dark background—follow this advanced export method.

Notably, exporting components separately is the only way to allow the slicer to fully respect the text_depth parameter. While you can increase this depth in the Customizer for extremely light colors, the default value of 0.85 mm is usually sufficient.

1. Export Separately: In the Export Settings section, use the Export Mode to generate and download the "Keycap Base Only" and the "Legends Only" as two separate STL files.
2. Import to Slicer: Open Bambu Studio (or your preferred slicer) and import both STL files at the same time.
3. Merge Parts: When the slicer detects multiple files and asks, "Load these files as a single object with multiple parts?", select Yes. This ensures the components are perfectly aligned and treated as a single multi-material object, allowing for better control over the legend thickness and color.

💡 Printing Recommendations

• Materials: PLA is excellent for decorative caps; PETG or ABS/ASA are recommended for durability. Based on my experiments, PETG requires smaller slot dimensions than PLA because it tends to shrink less, whereas ABS requires larger dimensions due to its higher shrinkage rate.
• Recommended Slicer Settings:
  • Wall Generator: Arachne
  • Seam Position: Back
  • System presets:
    • 0.2 mm Nozzle: 0.10 mm (Standard).
    • 0.4 mm Nozzle: 0.16 mm (Balanced/Quality setting).
  • Initial Layer Line Width: To preserve maximum detail on the legends, set your Initial Layer Line Width to match the default width used for the rest of the print. Do not use a thicker initial layer line, as it will blur the legends. In my case, I use 0.22 mm (for a 0.2 mm nozzle) and 0.42 mm (for a 0.4 mm nozzle).
• Warping & Bed Adhesion: If you encounter warping issues, ensure your build plate is thoroughly cleaned according to the manufacturer's instructions (for Bambu PEI sheets, use hot water and dish soap).
  • Fan Settings: If warping persists, try reducing the auxiliary fan speed. In my experience, especially when printing in a cold environment, turning off the exhaust fan (for H2 series) entirely can significantly improve bed adhesion and part stability.

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