This is a costumizeable bike light holder inspired by the 31.6mm bike light holder. My seat tube is too thin, so I redesigned it in OpenScad and made it costumizeable.

You need:

• 2 M3 nuts
• 2 screws, ~16-20mm lenght
• aluminum LED bike light

These aluminum LED bike lights are very wide spread and very cheap. Just search on ebay or aliexpress. They are powered by 2x CR2032 batteries lasting for quite a while if you use them in flashing mode. They are also bright enough for the rear light, but I would not recommend them for your front light. Note that sizes very a bit, you might need to adapt the parameters LIGHTDIAMETER and LIGHT_INSET. There are also USB chargeable ones out there, but I don't have one to try if the model fits.

All versions including latest

https://github.com/lumbric/bikelightmount

(I will upload new versions also here, if there are larger changes.)