Parametric Screw Cap (Bottle Caps Generator)

Never throw away a lost-cap bottle again! This MakerLab generator lets you create custom, perfectly fitting screw caps for almost any standard plastic or glass bottle.

I designed this specifically to be 3D-printable without supports. It features a custom trapezoidal thread profile that handles FDM overhangs easily, and an optional built-in inner sealing ring to keep your liquids secure.

Key Features:

• Quick Presets: Instantly generate caps for modern soda/water bottles (PCO 1881), older thick-neck bottles (PCO 1810), or standard 28mm glass bottles.
• Fully Custom Mode: Have a weird bottle? Switch to "Custom" and dial in your own inner diameter, height, thread pitch, and thread turns.
• Built-in Seal: Toggle the inner "olive" sealing ring on or off to ensure a watertight fit.
• Customizable Grip: Change the number of outer ridges or the thickness of the cap walls for better leverage.

Important Note on Food Safety: 3D printed parts have microscopic layer lines that can harbor bacteria. If you are using this cap for beverages you plan to drink from over multiple days, please consider coating the inside with a food-safe epoxy, or restrict its use to dry goods, utility liquids, or temporary transport.
 

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Update 1:
The cap will open screwed to the right (default).

But I added a checkbox to invert the screw direction.