Originally Posted by Spitball
Crank up the machine. That definitely helps, but let them face a pitcher throwing, also. The process has to begin while timing the pitcher's delivery into the total activity. The pitching machine does not allow for the pitcher's delivery.
Yes, obviously having someone pitch to them at that speed is the best option, then machine, then soft toss. I was assuming that was off the table since Big Klu said he had an old man arm. Working on their timing step is one thing you can do without throwing any pitches and that should help some of them a lot.
Another thing you could do is ask players on your team if they have an older brother, maybe a year or two older that could match the speed of the pitchers you are facing. See if they would come to practice and throw BP. Offer them a fountain drink or Icee after practice if they do.