AA battery to D adapter

thingiverse

I have designed a few adapters some using coins as the negative pole but this one was inspired by Seadevil using a paper fastener as the positive lead. I made mine in sketchup. There are 4 tiny protrusions that use friction to hold the battery in place so that it doesn't easily fall out. The protrusions are only 1 mm thick and can be sanded down if needed to achieve just the right amount of friction.