The LED lights on my e-bike are very bright. This is great for nighttime, but sometimes during the day I use the lights as "running lights" for safety, and they don't need to be so bright.
This is meant to be printed in a translucent or transparent PLA to allow some light through, scatter the rest.
Light OD size is about 2in/51mm
Pics to come.
Update: 100km review
This works basically the way I intended, it might be interesting to try it a little bit thicker. I only take the cover off when it's really dark now. The cover being printed in clear/translucent PLA makes it diffuse the light rather than blocking it completely.
License:
Creative Commons - Attribution - Non-Commercial - No Derivatives