C battery to D battery adapter

thingiverse

I'm using an adapter to utilize extra C batteries I have on hand for our baby swing, which requires D batteries instead. The plan is to create a connection between the positive terminals of the batteries by relying on the spring inside the battery holder to make contact with the negative terminal. To do this, food aluminum foil will be used to provide a path for the electrical current to flow. The idea is to modify the adapter's dimensions to fit snugly into place, making it easier to secure the foil in position. Update: As of 12/24/14, I've adjusted the design of the positive side to improve its functionality. This allows me to use a piece of aluminum foil to make contact with the battery holder's positive terminal. The instructions for this process are as follows: First, insert a small amount of household aluminum foil into the smaller inner hole of the adapter cap, which serves as the positive terminal side. This will establish a connection between the battery and the battery holder. For the negative side, leave the original setup intact, relying on the spring inside the battery holder to make contact with the C battery's negative end.