This mount replaces the original rubber strap holder of the Fischer rear light (and other lights with a square connector).
The light is held in place with magnets and can still be removed quickly and easily.

What you need:

• 2x Magnets Ø10 × 2 mm
• 2x Cable ties 2.5 mm thin
• Super glue
• Optional: rubber pad, electrical tape or duct tape (for the back side to increases friction)

Assembly:

1. Glue one magnet into the printed holder.

2. Glue one Magnet to the light. There are two options for you to choose from – there is a different holder version provided for each method:

• Option A (no drilling):
  • The magnet is glued directly onto the square connector of the light.
  • Tip: Place the first magnet in the holder, then a thin spacer, then the second magnet. It should protrude slightly. Apply super glue and press the light onto it. This way the magnet is perfectly centered.

• Option B (drilling):
  • Drill a 10 mm hole into the square connector of the light and insert the magnet flush.
    Advantage: The light can still be used with the original mount.
    Caution: There is a hollow space right underneath the connector, so it’s easy to drill too deep. The battery is located only about 6.5 mm below – use a depth stop! This may vary if you use other lights. 

3. Stick a small piece of rubber, duct tape or electrical tape to the back side of the holder to improve grip on the seat post.

4. Fix the holder to the seat post (27.2 mm diameter) using two cable ties.

Printing reommendations:

• Material: PETG
• Layer height 0.15 or 0.2 not bigger due to Staircase effect
• Place the holder in the slicer with the rounded back on the print bed.

• Supports required on build plate only – easy to remove.

Note:
If you need a version for a different seat post diameter or have other ideas for improvements, feel free to reach out – I’d be happy to adapt the design.