Like it or not, the tilt mechanism is a well established and
accepted part of today's pinball machines. There are five different
tilt devices, although they are not all present on every machine.
The most well known, and the one which most punters, if you'll pardon the pun, are familiar with is the pendulum tilt. This is situated inside the front of the cabinet to the left of the cash box. The active components comprise a conical-shaped plumb bob, which hangs on the end of a thin rod, and surrounding it is a metal ring. As the machine is nudged, the plumb bob swings around and should it make contact with the ring, a circuit is completed and the tilt is activated.
On electronic games, a number of such contacts are allowed before the CPU ends the ball in play. On most electro-mechanical games, it's instant death though, as the tilt relay energises immediately the first contact is made and ends that player's game. The lights and power on the playfield go out and the ball falls lifelessly to the outhole.
On early electronic games, tilting a game was usually accompanied by an electronic growl, but this was soon replaced with a verbal telling off, cackling laugh, or comical comment. I can remember being rebuked in various ways during my pinball playing career. Examples that spring readily to mind are "No class human", and "You have broken the light area", and more recently; "You're a funny guy", and "How dare you!"
The tilt can be made more sensitive by moving the plumb bob up the rod so a wider part of it falls inside the ring. On some machines the bob is fastened to the rod by a wing nut, but this is quite prone to falling off. More recent machines utilise a clip which tightly grips the rod. Pinching the ends together loosens it allowing the bob to be moved up or down.
The second type of tilt is the ball roll tilt. On the left hand side of the cabinet is a narrow, slightly sloping ramp containing a small ball. At the top end of the ramp is a contact. If the front legs are lifted off the ground by the player trying to prevent the ball in play from draining, the ball will roll up the ramp and touch the contact completing the circuit. The pendulum tilt should cut in as soon as the player attempts this, but the ball roll tilt system acts as a back-up in case it is missing, or set very liberally.
The other tilts fitted to pinball machines comprise sets of contacts mounted at strategic parts of the cabinet to detect abuse by the player. In electro-mechanical games these are usually, although not always, normally closed contacts wired in series with the hold relay's lock-in circuit. Banging the game opens the contacts and releases the hold relay ending the game.
Be aware that in early electro-mechanical games, and in the case of Gottlieb E/M machines as recent as 1970, these contacts carry 110 to 120 volts AC. Remove the mains plug from the wall outlet before investigating problems. In electronic games, they are usually normally open contacts which if banged, close and result in a slam tilt condition with the loss of the rest of the game for all players.
The active component for each slam tilt switch comprises a pair of contacts; one of the contacts having a longer blade than the other and a weight on the end. Following a slam tilt the modern electronic machine will do a cold start and power up as if it has just been switched on.
The most well known slam tilt switch is common to both electro-mechanical and electronic games. It is to be found inside the cash door and is often activated by a player trying to retrieve coins that have become stuck in the coin gauges, by banging on the front of the game. In this instance the weighted blade rests on the inside of the door. When the door is hit, the force bounces the weight back, either opening or closing the contacts depending on the type of game.
Different games react to this in different ways: some put Slam Tilt up on the display, while others give the player a more severe verbal message, set off a brief alarm, or merely reset.
A Bally electro-mechanical game I owned called Sky Kings had a bright light in the base of the cabinet and activating the slam tilt switched it on for a few seconds allowing a clearer look at the components!
Another slam tilt can be found on the underside of the playfield. One blade is attached to the playfield while the other with the weight is hanging below it. If the machine is picked up at the front and then dropped, the weight will bounce up and close the switch.
Finally, some electro-mechanical games have a tilt switch located in the backbox which prevents players who wallop it from getting a free game. Hitting the backbox can shock the sensitive parts inside into activating the machine.
The game in question was his first table built from scratch, called Advance, a 10 ball machine which had mechanical gates. When a ball was caught by a gate, another ball had to be shot in to a hole at the top of the playfield to open the gate which allowed the first ball in to the high scoring area of the playfield. This player was cheating by banging the bottom of the machine bouncing open the delicately balanced gates allowing trapped balls to pass through.
Williams took the game away and hammered thin nails through the bottom of it. Any player trying a similar tactic on it now would be in for an unpleasant surprise! However, Williams knew this wasn't a good solution, and invented a device which would stop the game if handled roughly. He called the device a stool pigeon. It comprised of a ball balanced on a pedestal which was surrounded by a metal ring. If the game was shaken the ball toppled off the pedestal and hit the ring.
Williams took the game back to the shop and kept watch. Soon, a player tried to cheat the game by nudging it. Sure enough, his invention worked. "Hey, I hit it and its tilted!" exclaimed the player. Hearing this, Williams changed the name from Stool Pigeon to Tilt, and so part of the pinball language was born.
A few years later, when electricity was introduced to pinball, Harry Williams invented the pendulum tilt.
Tilt pendulum permanently in contact with outer ring or ball in ball roll tilt is jammed against switch contact.
In electro-mechanical games, activating flipper button or start switch after power up, lights machine up until button released, then machine goes dead.
Hold relay's lock-in circuit faulty, check normally closed slam switch in coin door is definitely closed. Use shorting link to eliminate. Also, possible malfunction with game kick-off switch on bottom of motor board.
In early Gottlieb solid state games, machine will not complete power-up cycle and go to attract mode.
Check normally closed slam switch in coin door and ball roll tilt switch are both closed, and providing ground to control board IC Z29 pin 3.
In electro-mechanical games, hold relay drops out during game and machine goes dead.
Normally closed slam switch has dirty contacts or insufficient spring tension to remain closed.
Game cannot be tilted.
Missing tilt pendulum or set too liberally. Corroded ring or pendulum. Also, check for corrosion where pendulum hanger is connected to ball roll tilt system.
Game tilts too easily.
Lower pendulum on hanger. In electronic games, increase tilt setting from factory setting to five or more switch closures.
