Update: for a newer version with better internal wiring using only a 1.6mm /14awg wire, see https://www.thingiverse.com/thing:2647700

I had a spare 26.5mm "drop-in" LED bulb, so i made a handle for it. You could easily buy this for $12 CAD or about $9 USD but why buy when you can make out of scraps? It's SUPER BRIGHT - about 1000lm, about as bright as a 100W incandescent bulb, but unfortunately runs quite hot after 5 minutes (hence the semi-open air cooling design).

Non-printed Ingredients:
1 protected 18650 cell
1 LED flashlight "drop-in", 26.5mm version - these used to be $3 each but have since gotten more expensive. You can buy them now from aliexpress, the ultrafire.com site, dealsextreme, etc etc. You want the ones with a reflector and a driver board already built in.
1 clear plastic circle 26.5mm - you can cut this out of anything, i used a dremel on a demo lens (ask for these at your local optometrist or optical store, they just throw them out)
1 SPST latching switch from junk giveaway flashlights (seen in photo above)
2pc copper (or other metal) strips at least 70mm long

Assembly tips:
Pretty straightforward, but the back cap is a bit tricky because you have to ensure you have good electrical contact.

Print instructions

Category: Household Summary

Update: for a newer version with better internal wiring using only a 1.6mm /14awg wire, see https://www.thingiverse.com/thing:2647700

I had a spare 26.5mm "drop-in" LED bulb, so i made a handle for it. You could easily buy this for $12 CAD or about $9 USD but why buy when you can make out of scraps? It's SUPER BRIGHT - about 1000lm, about as bright as a 100W incandescent bulb, but unfortunately runs quite hot after 5 minutes (hence the semi-open air cooling design).

Non-printed Ingredients:
1 protected 18650 cell
1 LED flashlight "drop-in", 26.5mm version - these used to be $3 each but have since gotten more expensive. You can buy them now from aliexpress, the ultrafire.com site, dealsextreme, etc etc. You want the ones with a reflector and a driver board already built in.
1 clear plastic circle 26.5mm - you can cut this out of anything, i used a dremel on a demo lens (ask for these at your local optometrist or optical store, they just throw them out)
1 SPST latching switch from junk giveaway flashlights (seen in photo above)
2pc copper (or other metal) strips at least 70mm long

Assembly tips:
Pretty straightforward, but the back cap is a bit tricky because you have to ensure you have good electrical contact.

Print Settings

Printer Brand: Prusa

Printer: i3 MK2S

Rafts: No

Supports: Doesn't Matter

Resolution: 0.2

Infill: 15% 3 shells

Notes:

White PETG at 240C

Part orientation doesn't matter too much but you can try to orient all the parts so that there is no extreme overhang i.e. the ledge where the threads end.