Update: I have improved and clean up the design a little so it will be better for printing.

This thing is to adapt a standart 5 mm LED to the "Edison 10 socket" (E10) mostly used in old bicycle lights. I use it to re-equip old bicycle rear lights with light bulbs to LED. Especialy the nice old "Soubitez" from the pictures. As you can see I integrated the resistor into the light enclosure.

Notice:

• It is maybe not allowed to use it in bicycle lights or other vehicles (check the law in your country) ...

• you should use a external resistor and overvoltage protection to prevent the LED from damage.

• It is recomendet to use the adapter only in rear lights. And to use there bright red led's.

• You maybe have to drill out the center hole with a 1mm drillbit after printing. Thats because of the meltet and compressed first layers. To prevent from that you should print with 2 bis 5 layer raft.