Building A Pitching Machine

About this time every year as basketball season ends and Little League begins, my kids and I dust off our gloves and bats and head over to the local field to start practicing. We start off playing catch, mostly to warm up my aging and antique arm. After my arm is warmed up, I then throw batting practice to them. This has been our routine for the last 4 years.
So thanks to this unseasonable warm winter in New England we were able to get out there early this year. So after going through our normal routine, I walked over to the mound and expected my oldest to step into the batters box. However he refused to get into the batters box. When I asked him why-he says that I hit him with a pitch last year. It seems he hasn't forgotten the ONE time in 4 years of pitching over a thousand baseballs to him that I hit  him. So I tried to reassure him to no avail that it won't happen again this year but he still refused to step into the batters box. So after I pitched a whole bucket of balls to his brother, with out hitting him, we went home. When we got home we started talking and from our talk came the idea to build a pitching machine....................................... to be continued.....................................