This is a remix of the “A 3D printable bar-end that really works” – with an integrated mount for a bicycle bell. 

The bell can either be bought at AliExpress for about €1–4 (link but search for cheapest option yourself) or at Amazon for €12.99 (link).

What you need:

• Mentioned bike bell
• 1x Screw M6 x 25
• 1x Nut M6
• 1x Nut M4 (ideally self locking)

Assembly:

• Disassemble the bell. The original mounting plate is no longer needed.
• Insert a M4 nut into the dedicated opening in the printed part.
• Slide the printed cylinder between the rubber pads of the bell.
• Place the bell dome on top and loosely secure it with the original screw.

• Assemble the three expander parts using a M6 × 25 mm bolt and a matching M6 nut.

  

• Insert the expander into the handlebar and tighten it.
• Screw the bell holder with the Bell onto the expander.
• Rotate the bell to the desired position and then fully tighten the M4 screw.

Printing:

• Material: PETG recommended
• Bell holder part: 100 % infill
• Supports required bell holder part