Introduction: Masters A-50 Pitching Machine Restoration

About: I like to create, no matter the medium. I've made furniture, digital models, costumes, props, videos, graphics, animations, restored a vehicle, etc.

This is built by Masters Pitching machines who make the "Iron Mike." It's a model A-50. While this one was built in March of 1981, it looks nearly identical to the machines they currently produce today that retail for three thousand dollars and more. Why change a perfect design?

I found this thing at a former batting cage. It was outside with two others and hadn't been used in fifteen years, but at least it was under a shelter. There were still practice balls left in the feeder. I restored it to working order and mounted it on a concrete platform and adjusted the speed and height.

The Iron Mike is touted as being incredibly reliable. The pitching arm of the machine simulates a pitchers motion. This is desired because you want to simulate the in-game scenario as close as possible. The pitching arm helps you practice timing, which is better than the spinning tire machines.

The price was fifty dollars higher than I wanted, but I called the manufacturer before my purchase and discovered I could replace nearly all parts for $400. Chances were, I wouldn't have to replace everything. That's a lot cheaper than retail. They gave me an owner's manual and a price list through email.

Contact information: Master Pitching Machine, Inc Kansas City, Missouri 800-878-8228

I bought it and towed it away after cutting down two trees and removing a lot of brush. It weighs about 500 pounds I'm guessing.

To move it around, I used a 2x6 for mechanical advantage and put galvanized pipe under it to help it roll. The 500 pounds moves rather easily on rollers. I put it on wood blocks in my garage and cleaned it up.

• A-50 Pitching Machine
• chain tightener spring
• motor belt
• intermediate belt
• agitator drive belt
• bronze bushing set
• Replacement parts depend on what's wrong with your machine. The motor is one of the more expensive items.

• white lithium grease for the chain
• SAE 20 oil for bushings
• 3 prong power cord & wire nuts
• spray paint
• Armour all

• 2x4 and galvanized pipe to roll the machine around
• pliers to remove and replace the tightener spring
• wire cutters
• dremel with flap wheel
• tire iron, wrench, nail set, and hammer to replace torsion spring shaft bushings

Concrete Footing Supplies & Tools:
• Quickcrete concrete - 6 bags
• MDF for concrete forms with corner clamps and glue
• (2) 4x4's with (2) clamps to brace concrete forms
• rubber mallet
• plastic, rigid insulation, and blanket to insulate the concrete if it gets below 50* at night
• (3) 3/8" wedge anchors
• steel plate for anchor brackets
• Level
• Wheelbarrow and shovel for mixing concrete

Safety Concerns:
• This has a big spring that can generate a lot of force
• When working with electrical devices always utilize caution and make sure they are disconnected

Step 1: Repair Assessment

I assessed the condition after cleaning the machine up with compressed air. Everything had a bit of surface rust, but it was intact. I would replace all belts and lubricate bushings and the chain. The bushing for the cable end bell assembly of the spring shaft was badly worn or possibly non-existent and needed to be replaced. I checked all sprocket teeth and they were intact.

There were no guides online about repair, but I did find this disassembly video from Popular Mechanics.

Then the pitching machine sat in my garage for eighteen months. When I got back to the project, I cleaned up the motor and oiled the shaft with SAE 20 and spun the motor a few rotations. I also oiled the step pulley bushing, it's the second pulley off the motor from the left. I oiled the bushings where the tension cable attaches. I greased the chain with white lithium grease. Do not use WD-40 for anything. It's a detergent, not a lubricant.

I planned to bypass the coin op board just to check the motor. I had a spare three prong plug with cord, and I spliced it in at the box. There was some jerry rigging before me that bypassed the coin op box completely. That made this step much easier. That's fine with me, though I wouldn't mind a remote start button for it, though I'd have to run it underground or string it over the batting cage. I removed the flip switch and spliced in a power cord with wire nuts.

When I switched on the machine it worked! The tension sprocket spring had been stretched out, so I then cut it down a few times so the chain wouldn't jump off every time the arm rotated. Since this was indoors, I used wiffle balls to test it. I've never seen wiffle balls move so quickly. The machine can do 30-80 mph sixty feet away per the owners manual.

Step 2: Replacement Parts

I bought three replacement belts, I'll replace those when the existing ones break. I bought a new tension spring and a cable end bell bushing. The end bell uses two bushings. The previous owner had already giving me bushings for the cable ends.

diagram# (per owner's manual)/part#
(17)[761 074] motor belt 3L-44" $12
(14)[761 073] intermediate belt - belt A-50 $12
(6) [761 072] agitator drive belt 3L-60" $12
(21)[747 579) chain tightener spring $1.50
(53) [750 030] bronze bushing $2

I had originally planned to clean it, sand it, and paint it, but that's a lot of work. Since it will eventually end up outside, I don't mind if it looks shabby. That may leave anyone lurking in my area disinterested.

I left the tension spring as is since things seem to work, if it gives me trouble, I'll install the new one. Same goes for the belts. So far after thousands of throws everything is working fine.

To replace bushings, I first decreased the spring tension by turning the handle counterclockwise. Then I used a tire iron to twist the spring and remove the power cable.

I had to pull the cotter pin out the end of the spring shaft. I ended up using a nail set to push it out from the bottom as the pin would not pull out even with pliers. It's right next to the end panel, so it's a tight fit.

The shaft is then removed from the other side. I hit the cotter pin end with a hammer then use a pry bar to remove it further.

Unbolt the tension spring plate from the fixed end bell and the spring and end bells will come off the shaft.

There were bushings present, they were just badly worn. I knocked the old bushings out, then greased the bushing and end bell with white lithium grease. I used a clamp to press them into place. With the bushings in place, put it back together.

After trying the machine, I fixed the agitator. The agitator spins in the basket to push balls into the feeder. It has an arm on it that kept catching on balls, I used a wrench to bend it down. I also wire brushed the feeder and painted it so that balls would more easily roll down the feeder. I still occasionally have a ball that well get stuck in the feeder, even after spraying it with Amour All.

The only other deficient part is the red warning light lens that is long gone and the missing light bulb, with a piece of red plastic in its place. I plan to buy a trailer tail light lens and to fit it in place with a couple of screws. It's recommended the machine be mounted on a concrete pad or at least concrete footings. I'll add two concrete footings.

Step 3: Concrete Platform

The manufacturer requires the machine be mounted to a concrete platform or a split concrete platform. I opted for the split platform as it's a lot less concrete and thus cost. The recommended size is (2) 42x12x4 inch platform. I'm making them 6" tall, just to make access under them easier if needed.

I determined where I was going to install the platform. I'm mounting this under my deck for weather protection, and luckily it was already pretty level. I will also buy a tarp for further protection. This also lines up with my batting cage and puts the machine about 60' away from home plate.

I built two boxes with an open top and bottom out of MDF. These will be the concrete forms. Place the boxes on the ground. Since I'm measuring off of my deck columns, I'm leaving at least 6" of clearance. I ensured the first box was square to the deck columns. Make sure the platforms are square to each other. Then make sure they are level to each other. If your platforms aren't level, the machine won't sit level. I used a 4' level that spanned both boxes.

I used Quickcrete which recommended a 7 day cure time. A concrete guideline is that concrete reaches 50% design strength in approximately three days, 75% in about 7 days, 90% in about 14 days, and 100% in about 28 days. While I'm going to install wedge anchors to keep the machine in place, I should not tighten them until after at least a week. I also waited a week to drill the holes, but I could have drilled the holes after three days as long as I didn't load the anchor.. Before drilling the holes, I want to use the machine a few times just to make sure it's lined up as I see fit.

I mixed the concrete in a wheelbarrow, using a shovel to mix it. I used 2 additional quarts of water over what the instructions called for. You want the concrete dry as possible to retain strength, so mix thoroughly before adding more water. It needs to be just wet enough. Each form holds 240 pounds of concrete or 3 bags, I mixed 1.5 bags at a time. I shoveled the concrete into the boxes, but I quickly realized that 240 pounds of concrete was too much for my forms. I clamped wood 4x4's on each long side which helped brace the form.

After the second half of concrete filled my form, I used a rubber mallet to hit the sides of the form. This helps release any air bubbles. I then used a trowel to smooth the top. My calculations were correct, and the concrete reached the very top. While the concrete seemed dry during mixing, the top got wetter. This made troweling and smoothing out the top easier.

The ideal curing temperature for concrete is 50*. While the days were 60*, the nights were reaching 35*. I wrapped the molds (still in the wood form) with plastic, then cut rigid insulation to wrap the boxes, and topped that off with a blanket to hold everything together. This will help curing and keep it just a bit warmer. You don't want the concrete to be exposed to freezing temperature.

I planned to use wedge anchors for concrete. It's one of the stronger style of anchors, and while it may be overkill, why not. I'm using a 3/8" size as I already have that size masonry bit. Drill first, making the hole 1/4" deeper than required. The anchors required at least a 1.5" embed depth. Clean the hole then hammer in the anchor and put a nut on it.

The owners manual shows 2 hold down clips on the same side, with the rear one slotted for lateral adjustment. Another image shows 2 hold downs on the opposite side. To adjust laterally, clips on each side would restrict that movement. I didn't find many pictures online, but what I did see didn't appear to have any brackets, which makes me guess they aren't welded on.

I can buy the mounting brackets separately which look like flat plates from the manufacturer. I couldn't find any good pictures of what the brackets look like, but I'm guessing the machine is not going to walk forward. The brackets I assume are primarily for lateral adjustment and positioning. A bracket at one front corner and two slotted plates at the rear should be sufficient. I've got a piece of steel angle that will work. After a few weeks, I haven't bolted it down yet. I plan to... eventually, but it hasn't moved after numerous sessions. Before you mount it, run it a few times to makes sure it is aligned.

To move the machine into place from my shop, I used galvanized pipe as rollers, then a lever to lift it, sat it on blocks and then slid it into place onto the platform. I ran a pair of wood 4x4s in between the platforms, lifted the machine onto them, slid the machine into place and then removed the 4x4s to drop the machine onto the concrete platforms.

Once the machine is in place, run a few balls through to determine the lateral aiming before drilling into the concrete and installing the clips. I'd recommend a couple of sessions.

Step 4: Setup & Adjustment

Once the machine is in place, height and speed likely need to be adjusted. There is a tension spring plate at the fixed end bell. Adjustment where the plate bolts to the end bell is the major speed adjustment. There are (4) holes for adjustment. The hole closer to the ground/back of the machine is the least tension (slowest), the hole towards the front/top of the machine is the most tension (fastest).

There is also speed adjustment at the base of the arm with two cable attachment holes. Closer to the base is lower speed, farther from the base is higher speed.

Minor speed adjustment is made by turning the handle attached to the fixed end bell. Counterclockwise is slower, clockwise is faster. Knowing the machine can do 30-80 mph, and making a few assumptions, the slowest hole should put the machine in the 30-42 mph range, the next one in the 43-55 range, the one after that in the 56-68 range, and the highest hole in the 69-80 range. The adjustment at the pitch arm may account for an 6/7 mph change, with the handle providing an additional fine tuning of 0-5 mph. That's assuming the tension to speed correlation is linear.

The faster the pitch, the higher the ball, so if you adjust speed, you'll have to adjust height.

For height the handle to the right of the speed handle is the minor adjustment for height by raising and lowering the spring boom. Start with the spring boom centered before making adjustments. Height adjustment with the handle can be made while the machine is operating.

For major adjustment, loosen the pitch hand to change the angle. The hand more open will pitch higher, with it more closed will be lower. If you adjust the hand, make sure you have proper clearance with the ball guide plate. Adjusting the pitch hand just a small amount, can make a huge different 60' away.

Adjusting the machine wasn't difficult. It was already set to the 2nd slowest hole. The height was way too high, but adjusting the hand by just a 1/4" brought it down a couple of feet. Not even cranked up that high, it pitches pretty fast. I'm guessing around 60 mph. None of the human pitchers I've faced recently have thrown that hard.

The machine sits outside of my batting cage net, so I cut a flap out and have it hooked to the machine opening with plastic coated 14 gauge wire. I can disconnect it from the machine and tie the net flap back together when needed.

A piece of 14 gauge wire is tied to the machine. Additional pieces of wire hook from that wire to the net.

Step 5: Maintenance

The owners manual recommends daily oiling of the cable bushings at both ends of the power cable, the bronze bushings in the spring end bell assembly (at each end of main torsion spring), the bronze bushing at the step pulley (first pulley off motor) between motor and chain drive, and lubricating the roller chain using chain lube.

It also recommends one tablespoon of SAE #20 oil to the motor bearings after two thousands hours of use, though it cautions DO NOT OVER OIL. I didn't see a spot on the motor for oil, so I just applied oil to the shaft.

Repair wasn't bad at all, and I was glad I didn't have to pay for a new motor. This thing is a lot of fun though I have cracked an old wood bat and stress fractured an old aluminum bat.

Balls occasionally get stuck in the feeder despite having painted it and coated it with silicone. Throwing a ball at the machine usually knocks it enough to keep the balls rolling. There is no adjustment to the feeder unfortunately.

I still haven't mounted it with the wedge anchors, but the machine hasn't moved. I also haven't replaced the red lens and light bulb to indicate it's powered up.

The next upgrade will be to run PVC underground to the home plate end and add a push button to start and stop the machine. Currently I plug it up and run to the far side. A remote button would be nice.

Fix It! Contest

Participated in the
Fix It! Contest