Game Build Details
|Atomic Pinball Clock
Atomic Clock Build Details
Game Design Example
The Fun with Pinball exhibit includes a few original games designed to show how the pieces from the small boards work together.
|The Puzzle||The Puzzle|
|The Horse Racing Game||The Horse Racing Game|
|The Baseball Game||The Baseball Game|
Each game is designed from the ground up combining basic devices and assemblies used in electromechanical pinball machines from several different manufacturers. Most of the wiring is done with original cloth covered wire and cable lacing techniques to try to recreate the look of the era. The games are meant to be both entertaining and engaging for those interested in understanding more about how they work.
The Puzzle challenges players to determine the sequence of six buttons that will light all six lights (including the last light inside the pop bumper), much like a push button combination lock. Initially the player has no information about the button sequence and has to guess which button will turn on the first light. Once that button has been identified the player has to remember not to use it again while figuring out in what order the remaining buttons need to be pressed. The process is repeated for each button until all six lights are lit. When the last light illuminates, the bell rings and the game ends. The score reels at the back keep track of the number of guesses made. Lower guess counts represent better scores. Players are encouraged to try again for a lower score.
Both the button sequence (or the combination) and the length of the sequence can be changed with the plugs immediately behind the lights. Younger players often want to try again until they get through the game with the minimum number of guesses.
The Puzzle was built to feature the trip relay bank (the tall device behind the motor). Trip relays behave like circuit breakers; once they trip, they stay tripped until they are reset. So they're good for holding information for a long period of time while consuming no power. In this case the six trip relays are used to remember which lights have been lit. If you watch carefully in the video below, you'll see the trip relays fall in order as each number in the combination is found.
To make the combination sequential, each trip relay is dependent on the previous trip relay having been tripped. In other words, each relay's push button will only trip the relay if the previous relay has already been tripped, otherwise the button has no effect other than adding to the total number of guesses.
The score motor is used to drive sequences of events in a game. Each switch mounted to the motor generated a different event for whatever game the motor came from. Events are generated as the cams on the motor turn and teeth or gaps in the cams cause the switches to open and close. Events can send electrical pulses to other circuits when switches close momentarily, or they can deactivate circuits that have been active when switches that are normally closed open momentarily.
In this game the score motor is used at the beginning to reset the game. First it sends ten pulses to each of the score reels which is enough to reset them back to zero from any score. When they're resetting, score reels stop when they reach zero and any extra pulses are ignored. During the game no pulses are ignored so they can advance past zero (from 10 to 11 for example). The score motor also resets the trip relay bank at the beginning of the game. The large red solenoid at the bottom of the trip relay bank fires to mechanically reset all six trip relays at once.
At the end of the game the score motor turns one more time to send five pulses to the large chime at the back to indicate that the combination has been found and the game is over.
The plugs on the left behind the lights can change the combination by effectively rewiring which buttons will trip which relays. The plug on the right can change the length of the combination by skipping the first relay(s). For example to change the combination to just four numbers, the plug can short circuit the first two trip relays by making the third relay ignore them and wait only for its button to be pressed.
The relays along the left side are used to advance the guess count when each button is pressed, and to keep track of short sequences of events like resetting the game.
The transformer in the back corner generates 24 volts AC for all the relays and motor and 6.3 volts AC for the lights. These voltages are also brought out to a connector on the right side so that any of the small boards can be attached and draw power from the transformer.
More thorough explanations of parts of The Puzzle's design are detailed on the game design example page.
The Horse Racing Game was built to highlight the racing mechanism found in several horse and car racing themed games built from the early 1950s to the early 1970s. The mechanism features six horses pulled along by ladder chains that advance at different rates towards the finish line. The challenge is for the player to get their horse to finish first.
The game starts with the player selecting one of the six horses as their own by pressing the button for the selected horse. Once a selection is made, the light immediately above the selection button in the first row of lights illuminates to reflect the player's choice and the game springs into action. The second row of lights above the selection buttons starts to flash in groups of two or more at a time. The flashing lights represent the horses that at that moment would travel further than the other horses. The challenge for the player is to push the rightmost/advance button at the instant that the light for the selected horse is illuminated so that the selected horse will advance as much or more than the other horses. When the advance button is pushed, all six horses will advance a short distance, but those whose lights were illuminated when the button was pushed will advance more than the rest. The game continues until one or more horses reaches the finish line. If the selected horse wins the chimes play a short victory tune.
The tricky part is that the lights flash at a rate faster than most players are able to react to. So a strategy of waiting for the selected horse's light to come on usually means that it has gone off again by the time the player can react and push the button. A more reliable strategy is to study the flashing lights and look for the repeating pattern. Once the pattern is identified the player can usually anticipate when the light for the selected horse will illuminate so the advance button can be pressed at just the right instant. Of course, once the button is pressed and the horses advance, the pattern changes.
Since there is no time limit, the game is best played by taking your time, looking for the clues and anticipating when to push the button once you think you've identified the pattern. It's not about finishing quickly; it's about figuring out how to win.
The horse racing assembly is pretty interesting on its own. A motor with two sets of stators and windings is mounted below the horses. One winding is used to move the horses forward and the other is used to return them to the starting line. A plastic gear on the motor shaft is linked to a second plastic gear with a loop of ladder chain. The second plastic gear drives a common axle which in turn drives gears and chains that drive all six horses individually. The gear for each horse is mounted to the common axle with a leather slip clutch mechanism so some horses can be held back while others are allowed to advance. You can see this in action in the video at the end of this section.
After resetting the game the player selects one of the six horses by pressing one of the the six buttons grouped together on the front of the game. When a selection is made, a light in the first row lights to indicate the selection and all the lights in the second row start to flash.
The flash unit spins to select one of ten possible combinations of flashing lights. It stops momentarily when the player presses the last button so that the game can determine how much each horse should advance.
The trip relay bank on the left side keeps track of which horse was selected to win, and shuts everything off when the race is over. The transformer behind the trip relay bank is one of two transformers in the game. Different pinball manufacturers used different voltages in their games and since devices from multiple manufacturers were used in this game, two transformers were required. One supplies 24v AC for most of the devices and the other supplies 50v AC for the flasher unit. Both generate 6.3v AC for the various lights.
The score motor is used to reset the game, and to help determine when the various horses will advance. It also drives the score reels and generates the pulses for the victory tune played on the chimes if the selected horse wins the game.
Each time the player presses the button to advance the horses the alternator unit in front of the score motor fires and changes the pattern of the flashing lights. The player needs to reevaluate the pattern each time to anticipate when the light over the selected horse will turn on.
Switches at the ends of the horse tracks indicate which horse(s) won the race. If the selected horse won, the chimes play a tune.
Chimes and ladder chain gears How to play
A few more details about building the Horse Racing game are on the build details page.
The Baseball Game was designed to feature the Man Running Unit from a pitch and bat style of pinball machine which was popular from the early 1950s through the mid 1970s. The Man Running Unit replicates a baseball field complete with a team on the field and base runners that can run from base to base when the player gets a "hit". For this game the painted plywood ball field was replaced with a piece of clear lexan so the working parts of the Man Running Unit can be seen clearly.
When a new game is started the score reels are reset to zero, the balls to play counter is set to 15 and a ball is released into the inclined plunger lane. The player then gently launches the ball up the plunger lane through a series of roll under gates. The light next to each gate illuminates as the ball trips the gate and goes out when the next gate up the lane is tripped. Eventually the ball will stop and reverse direction leaving a single light illuminated representing the peak of the ball's travel up the lane.
Each gate in the plunger lane represents a hit (single, double, triple or home run), a strike or an out. Each hit gate is sandwiched between two gates representing a strike and/or an out. The idea is that the player needs the ball to peak at a gate representing a hit and avoid peaking at the gates that represent strikes and outs. At the very end of the shooter lane is a fixed target representing an out, so a ball launched too hard will always result in an out.
As the ball returns to the bottom of the plunger lane, it is diverted to a holding area while the game responds to the illuminated gate. If the gate represents a hit, a runner will appear at home plate on the Man Running Unit and run the appropriate number of bases while advancing any runners that were already on base. If the the illuminated gate is a strike or an out, the game will add those to the scoreboard near the front. Three strikes will be converted to an out, but all strikes are cleared on a hit.
Any runner driven home by a hit will add a run to the score and ring the small bell. Home runs will ring the large bell, and runs scored as the result of a home run will add extra balls to the ball count, potentially extending the game.
The arrangement of the gates in the plunger lane makes the player weigh risk against reward. The lower part of the lane has strikes and a single while the home run is at the end of the lane between two outs. A game could end in three shots if the player tries for triples or home runs and gets outs instead, but could go on much longer shooting for singles and doubles since strikes are cleared on each hit.
All of the mounting holes and some of the outlines of the ball field were transferred from the original playfield onto the lexan. The static players are made of cardboard and are mounted on steel wire which fits into holes in the lexan to hold them in place.
The Man Running Unit is suspended above the main body of the game on collapsible stilts to facilitate moving and storing. The back deck with the score reels, bells and ball count unit, and the plunger lane are also detachable.
The lights installed inside the game are for illumination, not for game play. Inside you can also see the score motor (left) two transformers (back) for 6.3v AC, 24v AC, and 50V AC, regular and trip relays (center and right). Barely visible in the back left is a resettable stepper unit that counts the number of strikes.
The Man Running Unit is a remarkably simple but very effective device to recreate the action of base runners in a baseball game. It has four arms with a base runner at the end of each arm. When the player gets a hit, the arms start to rotate and a solenoid activates briefly which raises one base runner from below the playfield as it leaves home plate. The base runners all advance the appropriate number of bases. When base runners reach home plate they are dropped back below the playfield.
The plunger lane is an elaboration on the idea of a skill shot found on some pinball machines where the player must carefully launch the ball to a specific spot to achieve a special award of some sort. The ball gate too is a feature found on other pinball machines. This game imposed a few constraints however that aren't typically part of a pinball machine and required unique designs.
Most importantly the working mechanisms all needed to be visible to the player. Ball gates and roll under switches have been used on pinball machines for ages, but many of their moving parts are typically installed below the playfield. Another constraint was that the plunger lane couldn't be longer than the rest of the game.
These two constraints added quite a bit of design complexity to the game beyond the usual wiring up of existing devices to do new things. The roll under gates used standard pinball machine switches, but the wire forms and brackets were all made from scratch with piano wire and aluminum angle stock. The ball gate used a standard relay with a piano wire hook to stop the ball between the two red posts.
Coming up with a simple holding area for the ball provided new level of appreciation for pinball machine designers. While conceptually simple, getting the whole thing to work reliably took munch longer than anticipated. The one way ball gate and upper red post need to deflect the ball into the switch that tells the game that the shot has completed. Then the ball needs to slow down enough so that the relatively weak ball gate can hold it in place until the game is ready for the next shot. Getting it all to work in the confined available space took several revisions. If you look closely you might see a few holes that were filled in where things were tried and removed.
The score motor was fitted with a clear cover to reveal the reduction gears inside.
More details about building the Baseball game are on the build details page.