This is the style by which the machine throws the balls.
“Wheel design” machines either uses 1, 2, or 3 spinning wheels to propel the ball. Generally the more wheels, the wider variety of pitches that machine can throw, such as curves, sliders, forkballs etc.
“Arm-action” machines from the Master Pitch company use a steel arm which rotates around to hurl the ball. The advantage of these machines is the batter’s ability to see the ball for a longer period of time, and work on timing as it’s released from the arm.
The draw-back of arm-action machines is that they can only throw fastballs, no “junk” pitches.
Wheel pitching machines can also allow batter’s to practice timing, but look for a machine with a long & highly visible “entry chute”, so there is a longer period of time between when the operator releases the ball and it’s projected from the machine.
Look for pitching machines that make minimal noise. Machines with apparent sounds during the ball release cause batter’s to key on the sounds to prepare to shift their weight, and we all know those noises won’t exist in game conditions, so your batter is being programmed to focus on the wrong cues. If needed ear-plugs could be worn to prevent un-natural conditioning.
We recommended buying from one of the main 5 pitching machine manufacturers. Yes there are alternatives, but these companies have proven track records for many years, and stand behind their products. We hope other companies emerge to compete which will only make the industry better, but until then we can’t recommend other manufacturers because we realize how much usage machines receive, and it’s imperative to use a machine with year’s of proto-typing under it’s belt, a high quality motor & great mechanics.
Look for pitching machines that throw a variety of types of balls, such as synthetic PVC, dimpled, & leather. Your batter will eventually want to practice using leather balls, but dimpled balls are good for practice environments and can be safer for younger inexperienced players.
Always uses the manufacturer’s balls or get a referral from them on the optimal ball for their machines, which have been calibrated to pitch a certain density ball at maximum speed & performance.
When you have selected your type of balls for a machine, always use 100% the same balls in that machine. Never mix & match dimpled & leather, or various manufacturers. The speed & pitch location can be significantly different & cause a safety hazard.