The making of hay for animal fodder has utilized many labor saving machines. Pick up hay balers are used to pick up hay located in windrow and make rectangular bales. Twine or wire is used to maintain the shape of these bales. In recent years the trend has been toward storing hay in larger units as compared with the smaller bales previously commonplace and capable of being carried by one person. These larger units are mechanically made with machines which roll the hay in large cylindrical or round bales having a diameter of about 6 feet and a weight of about 1,500 pounds. Another method of making larger units uses hay stacking wagons. These wagons are larger boxes which collect hay in a pile. Hay pick up and blower or conveyor structures are used to move hay to the top of the box. When the box is full of hay, the entire stack of hay is removed from the box to a storage location. An example of this machine is disclosed by Anderson and Neukom in U.S. Pat. No. 3,720,052. Another machine for stacking hay is disclosed by Carson in U.S. Pat. No. 3,538,696. This machine has a hay pick-up conveyor for moving hay to a platform. Sweep arms move the hay around the platform to build the stack.