Stem Cap Light Mount

Gain another mounting location for a light or bike computer by replacing your bicycle's stem cap with this part. The mounting tube is 31.8mm - the same size as many modern bicycle handlebars.

Similar to Paul's Stem Cap Light Mount, but this one can be made on a 3D printer.

Note that, this part will never be as bombproof as a Paul's part machined out of aluminum. This design was inspired by the Paul's part, but not a copy of it. However, this is an alternative that you can use to test fitment. If your light is not too heavy, it might work for you.

You can customize the design by checking it out:
https://github.com/thrasher/stem-cap-light-mount

Print Settings

Printer Brand:

Prusa

Printer:

I3 MK3S

Rafts:

No

Supports:

Yes

Resolution:

0.1mm

Infill:

25%

Filament:
Prusa ABS/ASA or PLA

Notes:

Print with at least 25% infill, with 3 shells, for strength.

Orient the part with the flat side surface on the print bed.
Supports on the bed are required in this position.

Print with ABS or ASA for UV protection. If you print with PLA, paint the part with a UV resistant paint to protect it.

Post-Printing

Installation

Stem caps on threadless bicycle stems are used to properly load the headset. This plastic part is not strong enough to do that, but can still be used:

1. Use the original stem cap to adjust the headset load
2. Tighten the stem's clamp bolts to the proper torque
3. Remove (and save) the original stem cap

4. Install this one, using the original bolt, but tighten it just enough to hold (not as much as required for stem cap adjustment)

   How I Designed This

   All code to create the part is found here:

   https://github.com/thrasher/stem-cap-light-mount

   The fillets between the parts were made using the excellent Fillets and Round code by Scorch. Unfortunately, they take a long time to render, so are disabled in OpenSCAD's preview mode. Use the render.py script to render for printing if needed.

Category: Sport & Outdoors