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Cat and her father drilled a hole into the printed prototype and stuck the rod into the hole and gorilla-glued it tight. Cat then let the glue dry and started to develop a plan to finish this project. Cat wanted to find an efficient way to put the solenoid together.

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Today, Cat created a design of the flipper in SketchUp. "Sketch Up" is the program that we downloaded on our MacBooks for 3D printing. While Cat worked on the 3D printing potion to our project, while Joe worked on research and Padlet organization. He did more research and organized the Padlet better. To organize the Padlet better, we took the categories that we created and filled them with much more information about our project and the Pinball Flipper itself, which is what our project is on. Both of us worked on this part of the summative more by starting to add more pieces to each of our categories. This consisted of images, videos, websites, questions answered, and many more.

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Joe and Cat updated more of the process journal. The process journal is where we state everything we are completing. We made sure that the audience will know what we did, how we did it, and in what order that we did it in. We need the Padlet to look presentable. By having these journal entries, we make ourselves look very presentable and we give off a tone to the audience. This tone we give off shows that we know what we are doing. Giving information of everything that we have worked on so far, what we are working on at the moment, and what we will be working on next and throughout the whole project, helps the viewers know more about our project and have a broader understanding of it.

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Cat and Joe finished the prototype file and are ready to 3D print the prototype. We got to this point by going over the prototype through Sketch Up over and over again until we came to one that worked for us. We then both looked at the way how our Padlet is presented. We realized that the way it is presented is not really an easy way to view our project and that looking at it does not give you a very well understanding of it. Because of this, Joe took organization to the next level. In other words, after discussing it together, Joe took the Padlet and changed the format to it and organized it better so that the audience can have a better understanding of it as well as the two presenters, ourselves Cat and Joe.

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Cat and Joe created the Padlet and started to do research. Although, before doing research, we had to figure out what we would be focusing on. We decided we would focus on the flipper, the pinball flipper. So we then looked at what we needed to accomplish and put that it into action. We picked a theme that made our Padlet more appealing to the viewer and took organization to another level. We looked at the requirements for our Padlet and our presentation overall. We then discussed it and figured out that we needed to answer the following questions given to us. We made a spot for those questions, a spot for the videos we might find, websites we found informational, screenshots we will soon have of our 3D printed items, and many more.

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We decided, out of all the options we were given, that Joe and I would make a Pinball Flipper Mechanism for out Pinball Summative in Physics class. We researched and developed new ideas and how we should make this work. Our results came out as planned and it was overall a great project to complete. We enjoyed working with a 3D printer and we are happy to be able to learn how to use it and how to incorporate it into this project.

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Today, after unfortunately putting it off for like two days, having people have theres in the printer before us, we put our final prototype in the 3D printer for it to start printing.

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Joe and Cat updated the process journal and built the final prototype of the pinball flipper. We updated the process journal by explaining everything that we have been doing. We used the "Sketch Up" program that we downloaded on our macs to build our final prototype. We then organized the Padlet better. We organized it better by first adding another category with memes about physics to get extra credit. We then added more questions and moved the questions and data around so the order it is in is an organized order. We made sure that the way the Padlet is set up and organized makes enough sense so that you can understand it well by looking through it and viewing it from an audience standpoint.

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Joe and Cat worked on finding new ways to discuss the building of the final prototype. We updated the Padlet, while also redesigning the prototype. We made the prototype during this class period and decided who was going to print the prototype next class.

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Today, Cat and Joe created the design of the flipper in SketchUp and decided to ask Mr. Muliawan about how they would print the prototype from an application called FlashPrint. We downloaded the application and loaded the design of the flipper onto this application called FlashPrint. After we loaded it on, we played around with the application to see exactly how it worked before we tried printing the flipper.

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Flipper Repair Introduction

Of the machinery in a pinball machine, the flippers may get the most use and therefore wear and tear. Therefore, the flippers may need more maintenance than any other part of a pinball machine.

Cautions: Must read before proceeding. Machine must be turned off and unplugged.

A glossary of terms used on this page.
Note: Click on any image or links for a larger image.
How a Flipper Works (Pre-1992)

In order to diagnose a flipper problem, it is important to understand how a flipper works. By far, the best description is by Steve Kulpa, and there is no reason for me to repeat it here. If this is too complex for you, a simple version for pre-1992 flippers goes as:

1) Player presses a button that closes a switch to complete the circuit
2) The high power portion of the coil is energized
3) The coil creates a magnetic field, drawing the plunger into the coil, hitting the coil stop
4) The flipper opens, opening the EOS switch (most designs)
5) The EOS switch inserts the lower power coil into the circuit, reducing the power and current draw
6) When the player lets go of the flipper switch, the spring retracts the flipper, removing the plunger from the coil
7) The loss of power changes the coil into a power generator. The collapsing magnetic field creates electricity. For SS (solid state) machines, a diode shorts out this power, preventing damage to the circuitry.

Note: EM pinball machines that have DC solenoids also have diodes on the coil.

Flipper Components

Flipper Parts - Contained in a Typical Kit from a parts supplier.

1) Coil Stop
2) Crank Assembly
- a - Plunger
- b - Link
- c - Crank Arm
3) EOS Switch
4) Spring
5) Coil sleeve

Optional (usually not included in the kit) - the bushing.

Two Different Types

Pinball flippers worked the same way from the dawn of flipper pinball until the 1990's. Prior to this change, full power went through every flipper switch and those switches burned out quickly which led to weak flippers.

About 1990, Data East / Sega (which became Stern), converted to computer controlled solid state flippers. Bally / Williams introduced Fliptronics about 1992 which also used low voltage and computer control. Sometimes, both these systems are referred to as Fliptronics, but that is a Bally / Williams term. The big difference between these two systems is the way we deal with their switches. The rest is the same.

When Should I Rebuild A Flipper?

Signs that a flipper rebuild is due are:

* When open, one moves further than the other.
* They are not aligned when at rest (this is usually a simple adjustment).
* They are sluggish or lack power.
* A flipper sticks and stays in that position when the power is turned off.
* You just purchased a used pinball machine and the previous owner cannot tell you when they were last rebuilt.

As flippers wear out, they lose power slowly. As a regular user, it is difficult to notice a gradual loss of power.

What wears out is the linkage in the crank assembly, where the parts rotate. The holes should be round. With time, they become oval. That means, as the plunger comes into the coil, there is an extra distance that the plunger has to travel until the flipper rotates and that saps power.

Other components that can reduce power to the flippers are the flipper button switch and the EOS Switch. For games prior to (about) 1992, the full power has to go through these switches, so any wear and tear on those two switches can sap the power. The easiest thing to do is replace those switches. EOS switches come in flipper rebuild kits.

Flipper button switches are not included in kits and must be ordered separately. It maybe possible to file those switches to restore their effectiveness, but this requires a certain technique - many people destroy these switches than fix them by filing them.

Worn flipper switch of the type that could be filed with a flexstone to improve performance. Filing or replacing these contacts are as important as the EOS switches.

Check to insure that the correct coil is installed (see your manual). Some previous owner may have just thrown in a coil they had handy. Too weak of a coil, and it will act like it needs a rebuild. Too strong and plastics may be broken.

Troubleshooting Flipper Issues

When a machine starts to have weak flippers, owners are quick to blame electrical problems. By far, the greatest cause of weak flippers are physical problems than can be easily diagnosed by those mechanically inclined.
Note: Never lubricate any flipper parts.
Mechanical Checks:

1) Turn the machine off and unplug.
2) Remove the playfield glass. Tilt the playfield up and lean it against the backglass. Be certain the playfield is secure and will not come crashing down.
3) Manually move the flipper back and forth. Listen for any rubbing. Be certain that the flipper does not rub the playfield. Pull up on the flipper. There should be a small amount of up / down movement.
4) Check for a broken or weak spring.
5) Check for wear on the Crank Assembly Link (see photo above). This is what usually wears out first. If the hole in the link has become elongated, replace the Crank Assembly or purchase a rebuild kit.
6) Plunger and/or coil stop become mushroomed. This can cause the flipper to stick open or not move freely.
7) If there is any doubt about the wear and tear of components including the Crank Assembly, springs, EOS switch, or Coil Stop, purchase and install a rebuild kit.
8) Inspect the EOS switch and flipper switch for pitting and wear.

Electrical Problems:

Read and understand " how a flipper works ". A great deal of current flows through the flipper coil when it is first pressed and any electrical resistance will slow it down.

Understand what type of flipper system you have. Generally, games older than ~1992 have the full power going through the flipper EOS Switch and Flipper Switch. Those get worn and require filing or replacement. Newer flipper designs have low power going through those switches and they wear slowly and must never be filed - see photos at the beginning of this page for an example contacts that must never be filed.

1) Turn the power off. Hook up a DVM across the two leads on the coil, where the two wires come in from the wiring harness. Set the DVM to the lowest resistance setting. With the flipper at rest, the resistance should be ~ 4 - 5 ohms. Higher values generally indicate a worn EOS Switch or, more rarely, a damaged coil.

Note that coils usually do not have to be replaced. When they do, it is because the flipper does not work at all. A bad coil rarely causes a flipper to be weak.

2) Touch the two leads of your DVM together. It should read nearly zero. This value is your zero value. Connect the leads across the EOS switch. It should read nearly zero. If not, file (older games only) or clean with isopropyl alcohol. For newer machines, this value does not have to be near zero.

The following tests are quite tricky, involve higher voltages and can cause damage if not properly completed. For qualified personnel only:

3) Jumper the EOS switch with heavy duty clip leads. Turn on the pin. Touch and immediately let go of the flipper switch. See if the flipper is stronger. Be careful not to hold the flipper button in since this jumper disables the EOS switch, sending full power through the coil. Holding the flipper switch in could cause a coil melt or a fuse to blow. Just a quick tap. If the flipper is stronger, the EOS switch is defective. Can try cleaning the switch with alcohol or file. Most likely replace.
If no change, then the EOS switch is good.
Remove the jumper on the EOS switch.

4) Lift up the playfield. Take a clip lead and connect it to one side of the flipper switch. Quickly touch across the flipper switch and immediately remove. Does the flipper seem stronger? If yes, file your flipper switch or replace it. If no, then it is not your flipper switch.
Note that doing this can cause quite an arc and scar the clip lead connector.

5) It could be the power supply to the flipper. Check for burnt connectors where the flipper circuit plugs into the power supply board or bad soldering. This is the least likely cause of weak flippers.

Flipper Diodes

A diode conducts electricity in one direction only. It is there to protect the sensitive electronics in solid state (SS) pinball machines.

Why diodes? When flipper coils are activated, electricity runs through the coil. When the flipper is turned off, the magnetic field around the coil collapses and the coil turns into an electric generator and power runs in the opposite direction. The power generated by the coil can fry the electronic controls. The diodes conduct electricity one way and short out the collapsing field. Without those diodes, the circuit board will fail. If the coil is installed with the wires switched, those same diodes will conduct when the power is applied to the coil which should blow the fuse.

Electrical Mechanical (EM) flipper coils do not have diodes because they run on AC. The EXCEPTION is those later EM machines that run on DC (Ex: Captain Fantastic). DC machines have a bridge rectifier that converts the AC to DC. Without those diodes, that rectifier will fail.

When rebuilding the flippers, take the time to inspect the diodes. Put a little bit of stress on each one with a screwdriver. If they break apart, replace the diode. The diode marking must be in the same direction as the orginal diode (see photo below).

If replacing a coil, be sure to check the diodes on the coil to see if they are 'pointing' in the same direction. If they are, connect the wires to the new one in the same order. If the direction of the diodes are reversed, then reverse the wires.

The drawing above shows the symbols of a coil and a diode. A flipper coil would have two coils and two diodes. To the right is a flipper coil with its two diodes. Looking closely at the picture (click for larger photo) shows the bands on the bottom of each coil indicating direction of the diodes.

Rebuilding the Flippers

The easiest way to rebuild a flipper is to order a flipper repair kit from a pinball parts supplier.

Tools Needed

1) Screwdriver (Phillips)
2) Allen Wrenches (some flippers)
3) Needle Nose Pliers
4) Wire Cutters
5) Soldering Iron & Solder
6) Nut Drivers and/or socket wrenches
7) Flexstone (for non-computer controlled)

Optional: Flipper gauge. Nice to have. But making sure of a small amount of vertical movement is usually sufficient.

1992 And Newer Flippers

Newer machines have EOS switches that are normally open, then close when the flipper is activated. These switches process low voltages and should never be filed. These are either gold or silver plated. Some other EOS switches on newer machines (like Stern) are normally closed, then open when the flipper is activated. These are also gold or silver plated and should never be filed. The EOS switches can be cleaned by inserting a business card and dragging it across the contacts as they are held closed by your fingers. Or they can be cleaned with Q-tips and a small amount of 91% isopropyl (not rubbing) alcohol (Note: flammable - see cautions).

Note that this EOS switch shows almost no wear. It belongs to a Williams / Bally Fliptronics pin. These are recognizable because the switches are open when the flipper is at rest. These switches can last longer than the linkage.

This is a flipper switch for an early fliptronics game such as The Addams Family. Some fliptronics games used optical switches that do not have metal contacts.

How To Rebuild a Pinball Machine Flipper

Prior to beginning disassembly, pull up and down on the flipper itself. Notice that there is a small amount of vertical movement. When re-assembling, it is crucial that there be a little bit of up and down movement on the flipper bat, or the mechanism will bind and not swing freely.

The procedure for early full power EOS, Fliptronics and DE/Sega/Stern flippers is nearly identical. The only difference is the treatment of the switches. Never use anything abrasive on Fliptronics or low power DE/Sega/Stern flippers.

Steps: Caution: Insure the machine is turned off and unplugged.

1) Remove the flipper by loosening the nut holding the flipper bat shaft. Some flippers are held in place by two set screws and an Allen (hex) wrench is required. Others are held in place by a combination of a nut and an Allen bolt like the Williams assembly to the right. Some require only a socket wrench to loosen.

2) Remove the flipper coil stop (#1 in the above ' Components '). This may require a nut driver or allen wrenches.

3) At this point, the solenoid coil and crank assembly will no longer be held in place. Remove the coil from the plunger and let it hang by the wires.

4) Use your needle nose pliers to disconnect the spring from the base.

5) Clean out the bushing hole for the flipper shaft. I use several q-tips or a towel and small amounts of isopropyl alcohol. Some kits include a new bushing. Note, if the flipper dragged on the playfield, likely cause was this worn bushing. Replace it.

6) Inspect the diodes on the coil. Carefully insert a small screwdriver behind the diode and push slightly to see if it is broken. If one is broken or suspect, replace it. Note that some coils have two diodes, others just one and some do not have any at all.

7) Replace the coil sleeve. Check to see which end of the coil has the sleeve with the collar. Press out the sleeve from the other side, then insert the new one with the collar on the same side. It maybe impossible to remove some sleeves. That is usually because the coil overheated and is ruined. Replace the coil and use a new sleeve.

8) Note that in the kit, there is a left and right crank assembly. Compare the new ones with the one you have removed and select the identical one. Attach the new spring (to the plunger or to the tab, depending on your type of spring).
Note: Some flipper systems have the spring on the shaft. If yours does, be sure to insert it through the plunger. The larger loops go towards the coil.
Here is the only tricky part - insert the crank assembly through the solenoid bracket, (add spring now if like that to the left) then into the coil (diode / wire end towards the crank assembly, if possible).
Hold all three parts together and insert the coil into the new coil stop from step #2. While holding this all together, manipulate the crank assembly into its proper position so that it is ready to be connected to the flipper bat shaft. If this assembly had a spring on the plunger, be certain to install it prior to inserting the Crank Assembly into the coil.

9) If the original coil stop had a washer / spring attached, set it on the new one. Attach the new coil stop, removed in step #2, to the base plate. At this point, all components should be held into place.

10) Insert the flipper bat shaft through the playfield and into the crank assembly. Tighten the shaft so that it is secure and cannot fall out, but do not over tighten.

Pull up and down on the flipper bat. There should be a little up and down movement.

11) If spring is outside the plunger, attach it the other end to the bracket. Needle nose pliers make this step easier.

Replacing the EOS Switch - Soldering Iron Required

Types of EOS Switches:

a) Simple high current switch made of tungsten
b) Complex high voltage switch (see Bally linear flippers, above) which includes a lane change switch
c) Simple low voltage switch (usually '92 and later).

Types a) and b) are closed when not in use. In b), the lane change part of the switch will be open.
Type c) will be open when the flipper is not in use (normally open) in the Williams / Bally Fliptronics pins. In other pins, like DE/Sega/Stern, EOS switches are low voltage, but are closed when the flipper is not in use (normally closed).

12) Note the orientation of the EOS switch, which side faces the coil and which leaf is hit by the flipper as it opens. Remove the screws holding the switch. Leave the old switch dangling by the wires.

13) Mount the new EOS switch in the same orientation as the old one. Tighten the screws firmly.

14) One at a time, unsolder the wires from the old switch and attach them in the same place on the new switch. If there are only two wires, location is not crucial. But if it is a multilevel switch, it is crucial that the wires be connected to the same tabs.

Make absolutely certain that none of the wires from the EOS switch are touching or shorting anything else. On many systems, these wires carry high voltage and can fry other components.

Tightening the Flipper Bat

At this point, the flipper bat shaft should be firmly, but not tightly, connected to the crank assembly in step #10. Check its position in the playfield. It should be possible to swing the flipper bat into various positions.

15) While holding the flipper mechanism in the closed (at rest - power off position) below the playfield, swing the flipper bat above the playfield. If the bat turns too freely, tighten the screws or bolts holding the shaft in place. If it is difficult to turn, loosen these screws or bolts just a little. Make certain that there is a little up and down movement as noted prior to step #10. Use the Flipper gauge if you have one.

16) Swing the bat into the desired position. If there are small markers in the playfield, the bat should either point at the marker, or rest on it. If the alignment point is below the flipper, insert a toothpick into the marker and set the bat against the toothpick (without the rubber). If no markers are present, set the bat parallel to the wire on the playfield.

17) Tighten the bolt / screws on the crank assembly. If after a few minutes of game play, the flipper bat starts to shift position, it was too loose.

It is possible to over tighten the type with a bolt. Some people will crank those so hard, that the two pieces bend and touch each other - don't do that.

Adjusting the EOS Switch

18) Crucial: Check the EOS switch adjustment. For non-Fliptronics pins, the EOS switch must open when the flipper is activated (up). The EOS switch should open as late as possible so that full power goes to the flipper as long as possible.

For Fliptronics EOS switch: switch is open when the flipper is at rest. Closes when the flipper is fired. Note that that this is the opposite of what happens with older style full power flippers.

19) Rebuild the other flipper. When finished, the two flippers should sit at the same angle. Try playing the pin. Readjust the position of the flippers if they seem incorrect to you. I mark the date if flipper rebuilding with a sharpie on part of the metal (not the coil or plunger).

Copyright 2006 - 2018, all rights reserved.

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Pinball Flipper Rebuilding - How to Fix and Replace -

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Of the machinery in a pinball machine, the flippers may get the most use and therefore wear and tear. Therefore, the flippers may need more maintenance than any other part of a pinball machine. Cautions: Must read before proceeding. Machine must be turned off and unplugged. A glossary of terms used on this page.

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As part of my plan to build an Arduino controlled pinball machine I'm testing out some cheap solenoids installed on simple flipper designs I have 3D printed. This is also an Arduino project testing out how to control the solenoids, and learn how they react and what force to expect with different geometry.

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This is a follow-up to the original post on controlling solenoids with a Pinball Controller's "Power Driver 16" board. I'm adding some photos to aid with the wiring and assembly, as well as giving a few troubleshooting tips.

Click through to see a larger image. This is an overview of the Power Driver 16 and Mini RS-485 Master, showing the inputs, Mini Master output, and connection to the solenoid driver.

Click through to see a larger image. This detail shot shows the inputs to the Mini Master: Orange wire is Power (5V), Blue wire is TX from the Arduino, Black is GND. The outputs of the Mini Master are: White for TX(+) and Black for TX(-).

This is a detail showing the Mini Master output coming in on the Pinball Controller's Power Driver 16 port labeled J9. Pin one is Serial +, which gets the White TX(+) wire, and pin 2 is Serial-, which gets the Black TX(-) wire from the Mini Master.

Click through for full size image. This shows the Arduino SPI interface to the Mini Master RS-485 converter. It is a three-wire connection, with 5V power, signal and ground.

SPI interface uses the GND, MOSI and 5V pins when connecting to the Mini Master RS-485 converter.

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This is a follow-up to the original post on controlling solenoids with a Pinball Controller's "Power Driver 16" board. I'm adding some photos to aid with the wiring and assembly, as well as giving a few troubleshooting tips. Click through to see a larger image. This is an overview of the Power Driver 16 and...

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If you are contemplating building your own machine, then you probably already know a good bit about how pinball machines work. It's basically series of electro-mechanical events where a steel ball activates a switch, which in turn fires a solenoid that drives a mechanism, sending the ball off in some other direction where it most likely hits another switch, and so on and so on...

The Flippers are the only real interface to the game: You manually activate a switch that fires a solenoid, which then drives the flipper mechanism... The issue that becomes apparent with Flippers is that you want high-power (and high current) when you're hitting the ball, but you don't want to burn out your flipper coils if you hold the buttons too long. These problems have been solved during the long evolution of Pinball, with somewhat complicated results.

It's understandable that there are often questions about connecting and firing Flippers; With their double-wound coils, multiple recirculation diodes, and end-of-stroke (EOS) switches, it's easy to get confused if you're hooking them up for the first time. And to make things more complex, today's modern control systems have the ability to do many more things, like fire the "power" and "hold" coils independently, apply "patter" to the coils, feed the EOS switch into the controller as a normal switch, or even bypassed it completely.

I'm not going to make a case for what is the best way, but I will elaborate on each of the pro's and con's and let you decide what works best for your own Custom Pinball Machine...
Background on the standard 70's- or 80's-style setup:
Most early games fired the Flippers directly off of the cabinet flipper buttons, using high-power contact switches. In addition to this, there was some sort of relay in series with the circuit that could enable and disable the flippers between games, or even between balls. Here's a diagram of a standard vintage-style setup:

And typical vintage-style EOS switch setup and function:

In the above diagram, the EOS switch is Normally Closed (NC) before activation. The switch is shorting out the "Hold" coil, which is a higher resistance and would otherwise limit the current. One the Flipper has reached full stroke, the EOS switch opens, adding the "Hold" coil to the circuit. This reduces the current while maintaining enough of an electro-magnetic field to keep the solenoid in position. On a side note, the typical convention for labeling coils is to indicate the wire gauge, followed by the number of turns. So "25-500" is 500 turns of 25Ga magnet wire. The hold coil is labeled "34-4500", so 4500 turns of 34Ga magnet wire. Low gauge is thicker wire, with less resistance and higher current carrying ability. Resistance also increases with length. So more turns at a higher gauge will yield a much higher resistance than fewer turns at a lower gauge, even if the same amount of copper is used.

Speaking from personal experience, about half of my Custom Pinball games use this type of setup. The specific relay (and corresponding socket) that I have used to enable the flippers can be found here:

You have a couple of options in wiring up this circuit. I like to have the relay on the high-voltage side of the flipper coils, and use the cabinet buttons to switch the ground side of the coil.

If you're interested in using this old-school method, or possible have scavenged parts from vintage machines, here are a couple links that describe how these older circuits work, and how to properly repair older Flippers:
Old-school Advantages:
Zero latency from button push to firing the flippers. And, only one solenoid driver channel is used, just for the relay.

Old-school Disadvantages:

As simple as the circuit is, it can be a lot of wiring to get power, ground, buttons, flippers, and solenoid driver lines all to a central relay. Power of the flippers are not independently adjustable.
Variations on the Old-school circuit:
From a power supply standpoint, one concern with flippers is that their high-power coils produce large current surges (see the previous blog post for more info on power supplies). This could become a problem particularly on multiple-flipper games. However, I have wired four-flipper games in parallel without any issues. If it is a concern when building your own Custom Pinball Machine, there are clever variants that uses the EOS switches to stagger the firing of the upper and lower flippers. The advantage being that the surge current is spread out over time, so each flipper gets the full power available. Primary flipper requires a DPST leaf-switch, circuit diagram here:
Modern Systems:
If you're building a Custom Pinball Machine, the controllers and drivers available today allow for independent firing of both the "power" and "hold" coils, or they can adjust the duty cycle of the voltage to the solenoid so that only a single "power" coil is needed. The EOS switch can be used to tell the controller to go to a much lower duty-cycle, or the EOS switch can be bypassed completely and a timer function used instead to switch to a low-power mode. This modern technique uses PWM, sometimes called "patter". Here is a good breakdown of the various methods that can be used today:
Modern Advantages:
It's much easier to wire flippers directly to the driver, and have cabinet buttons go to the controller. I currently have two Custom Pinball Machines wired this way, and I can see how the ease of wiring justifies the downsides. Plus, you have full control over flipper power, and could even manipulate the power as part of the game rules.
Modern Disadvantages:
Having the Flipper buttons sent to the controller, and then the controller signal sent to the driver, can introduce latency (that is, a significant delay between pushing the button and seeing something happen). This is by far the most commonly cited disadvantage. However, I can say from personal experience that it's barely noticeable (or not detectable at all), even with a relatively low-speed controller like an Arduino. With that said, there are other potentially more critical disadvantages... Eliminating the EOS circuit is not "Fail Safe". Having the high-power coil under computer control could lead to problems, especially during development and testing, or as a machine gets older and less reliable.

Another disadvantage is that configurations firing two coils per Flipper (independant "power" and "hold") can eat up available driver channels pretty quickly, especially on multi-flipper games. But this would only be a corner case where the EOS switch was eliminated, while retaining the "hold" coil (as in situations where PWM "patter" drive is not an option).
Where to Buy:
Aside from eBay, and especially if you want new hardware, the best places to buy Pinball Flipper Mechs are from Marco Specialty or Pinball Life:

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If you are contemplating building your own machine, then you probably already know a good bit about how pinball machines work. It's basically series of electro-mechanical events where a steel ball activates a switch, which in turn fires a solenoid that drives a mechanism, sending the ball off in some other direction where it most likely hits another switch, and so on and so on...

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6.8 - How do flippers work? (Pinball Technically Speaking)

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The flipper mechanisms differ from company to company - that's one of ...

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A solenoid actuator can be defined as an electromagnetic device that converts an electrical signal into a magnetic field. Solenoids are available in a variety of formats; the two more common types are the linear solenoid and the rotary solenoid.

In a Linear Solenoid (LS), electrical energy is converted into a mechanical pushing or pulling force or motion. Inside the LS, an electrical coil is wound around a cylindrical tube with a ferromagnetic actuator, called plunger. When electrical current flows through the coil, a magnetic field is instantaneously generated. The direction of this magnetic field is determined by the direction of the current flow within the wire. Thus, the coil becomes an electromagnet with its own north and south poles: in such a configuration, the coil behaves exactly as a permanent type magnet. The strength of the magnetic field can be increased or decreased by either controlling the amount of current flowing through the coil or by changing the number of turns (loops) of the coil windings.

When an electrical current is passed through the coil windings, the plunger, which is is free to move (to slide) in and out of the coil body, is attracted by the magnetic flux. Accordingly, the plunger translates towards the center of the coil body. Such translation results in the mechanical pushing or pulling force provided by the LS. The force and speed of the plunger movements is determined by the strength of the magnetic flux generated within the coil (which depends, as mentioned above, on the amount of electrical current). When the supply current is turned off (de-energized) the electromagnetic field collapses and the plunger is allowed to go back to its original rest position. This is usually achieved passively, by means of a back and forth movement of the plunger is known as the LS's return spring (a small compression spring attached to one end of the plunger itself). Both push- and pull-LS types are generally constructed the same with the difference being in the location of the return spring and design of the plunger. Th e stroke, in other words the maximum distance the plunger can travel in either in or out direction. LSs can be used to electrically open doors and latches, open or close valves, move and operate robotic limbs and mechanisms, and even actuate electrical switches just by energizing its coil. LSs can also be designed for proportional motion control, were the plunger position is proportional to the input power.

Analogously, a Rotary Solenoid (RS) provides the rotational movement of the plunger in either clockwise, anti-clockwise or in both directions. The coil is wound around a steel frame with a magnetic disk connected to an output shaft. When the coil is energized, the electromagnetic field generates multiple north and south poles. These poles repel the adjacent permanent magnetic poles of the disk, causing the latter to rotate at an angle determined by the mechanical construction of the rotary solenoid. Therefore, the shaft rotation can be controlled by either energizing or de-energizing the RS, or by altering the position of the permanent magnet rotor.

Commonly available RSs have strokes of 25, 35, 45, 60 and 90degrees, as well as multiple movements to and from a certain angle. RSs can be used to replace small DC motors or stepper motors were the angular movement is very small, with the angle of rotation being the angle moved from a desired start position to a specific end position. RSs are used in vending or gaming machines, valve control, camera shutter with special high speed.

Check out this website for many other useful hints about solenoid switching, energy consumption and duty cycle 🙂

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source: this website A solenoid actuator can be defined as an electromagnetic device that converts an electrical signal into a magnetic field. Solenoids are available in a variety of formats; the two more common types are the linear solenoid and the rotary solenoid.

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UPDATE: Completed flipper design: https://youtu.be/4IaZik4l6m4 I'm building a 3/4 scale pinball table. As parts arrive from china i thought i'd construct a test table so that i can test out each element and work out what engineering challenges i am yet to face. The table is 27cm x 40cm on a 4 degree incline.

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We learned that a pinball flipper is a mechanism used to hit the ball within a pinball game. The pinball flipper is usually made using hex coils and a flipper button. Generally speaking, when the flipper is triggered by the solenoid, a high magnetic field is produced that pushes the flipper up in the desired movement.

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The device needs to be connected to an electrical circuit, including a working solenoid of a pinball "flipper."

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How does the solenoid movement turn into the desired movement?

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How does the solenoid movement turn into the desired movement?

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The solenoid movement turns into the desired movement by going from pushing up the spring around the pipe to trigger the flipper to having the flipper be triggered to flip up which is the desired movement that needs to occur.

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The solenoid pushes the metal to the middle. It then pushed the spring up around the pipe so that it would trigger the flipper to go upwards.

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When the switch is closed, the spring will pop out.