Take a 1/4" dowel rod and sand it down till it's snug in your arrow . Cut a 1/2" section off . Put a small amount of Gorrilla glue(dont use super/fletching glue) on the wood . Insert the rod into the arrow . Take a "Thill" bobber light , put it in your nock then push the rod in until the nock is seated , and the light is on . Take out the light and nock and let stand over night . Don't leave the nock in . It may get glued to the shaft .
I have made several of these , and they work every time . It adds a little weight to you arrow , but about the same as other lighted knoks .