AA battery to D adapter

thingiverse

I've crafted several adapters, some employing coins as the negative terminal but this one was sparked by Seadevil's innovative use of a paper fastener as the positive lead. I created mine using sketchup. Four minuscule protrusions utilize friction to secure the battery in place, preventing it from slipping out easily. These protrusions measure just 1 mm thick and can be sanded down if necessary to achieve the perfect amount of friction.