Singer 500A "Rocketeer" Machine Problem
 

Suddenly my Singer 500A Rocketeer sewing machine will not wind bobbins. My DH who is excellent at repairing mechanical and electrical items is perplexed over this issue. He changed out the rubber wheel/gasket inside, but yet, my machine still will not wind bobbins. Help! Any idea what we need to do? This is my "go to" machine for heavy duty fabric items that I am currently sewing. Feel free to send me a PM if you have solutions!!