E26/E27 bulb sockets cost $3 to buy, this costs 0.30 cents to print! That's 90% savings to help justify your 3D printer purchase.

I found Salvatore's 3D model fit the threads of light bulbs very well, however I wanted a more traditional way to mount it that just uses either screws or gorilla glue.

I don't recommend using this with an incandescent bulb for too long due to heat, however that Is what I have intended for mine. I plan to use these to hold a light bulb which will be used as a big resistor for an electromagnet. It should be able to hold LED bulbs for a long while though since those don't normally get too hot these days.