This is an alternate pipe cap end design for OpenSCAD, which can be customized according to your need.

• full, single cap - measure closely to your inner diameter
• split cap, fix with screw - allow a bit more tolerance.

The split cap will fix very firmly with a proper screw. Look out in OpenSCAD when rendering, for a hint about the minimum screw length.

• Suitable for a wide range of sizes
• Customizable
• Fix firmly (split variant)
• Easy to remove (depends on tolerance to inner diameter)
• Easy to print (no supports)
• Screws from M3 to M8, several screw head models.