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The Lightning Leap

A Meccano buzz-wire game of skill

Background

In 2002 I built a classic buzz-wire game with wood and wire for the Foal Farm Animal Rescue Centre country festival. In this game, which I named ‘Catch the Cat’, winning players heard a cat meowing, while losers heard the sound of a dog barking.

The Meccano version allows players to win real money, while losers cause the game to ‘catch fire’ by illuminating two silk flamelights. The name of the game was inspired by these flamelights and the shape of the buzz-wire.

Over the years this game has helped raise hundreds of pounds for Foal Farm.

The Lightning Leap set up at the International Meccano Model Show in 2011
The Lightning Leap set up at the International Meccano Model Show in 2011

Coin slot

When a 2p coin enters the coin slot, it travels down a chute where it activates a switch to start play before falling into the top of the coin dispenser. An electromagnet pulls a short rod across the coin slot to prevent further coins being inserted.

The coin slot, electromagnet and coin overflow hopper inside the right-hand tower
The coin slot, electromagnet and coin overflow hopper inside the right-hand tower

Coin dispenser

Many ideas for the coin dispensing mechanism were tested, but it became apparent that none could fit inside a 5½” square tower as originally intended, so the towers were increased in size by two inches and heightened. This made it much easier to fit the flamelights, electronics and other mechanisms, but also made the game more expensive to construct.

The coin dispensing mechanism inside the right-hand tower
The coin dispensing mechanism inside the right-hand tower

Coins collect in a tube of three cylinders, held in place such that no bolts can obstruct the flow of coins. This design was inspired by Brian Leach’s similar solution inside his Belly slot machine model.

A gap at the bottom of the cylinder allows a single 2p coin to be dispensed for every full movement of a cam, while a microswitch actuated by a cam on a 1:5 ratio gear allows five coins to be dispensed in total, giving the player 10p winnings.

The coins in the cylinder sit on a sprung balance so that should they run low, the mechanism will stop and there can be no further play until the dispenser is refilled. In use, with a sufficiently difficult buzz-wire course, this situation should not occur, and the dispenser should eventually overflow with further coins falling into a hopper.

Buzz-wire and wand

The design of the game allows players to begin from either end of the buzz-wire. Each end is electrically isolated from the casing and the buzz-wire. The dual-loop design of the wand serves to increase the game’s difficulty so that the buzz-wire course can be less complex.

The game in play at the Greenwich Great Get Together in 2011
The game in play at the Greenwich Great Get Together in 2011

Electronics

The sequence of events during the game is determined by the state of 15 relays situated inside the left-hand tower, mounted on a frame so that they can easily be removed for maintenance if required.

The relays inside the left-hand tower
The relays inside the left-hand tower

Because of the power draw from the two flamelights and the electromagnet, the game is supplied with 4A at 12V DC.

Circuit diagram

Circuit diagram
Circuit diagram

Sequence of events

  1. The Wand rests at either end of the Wire.
    Either the Left or Right Safety Buffer relays are actuated.
  2. An inserted coin actuates the Coin Slot Switch so that both Coin Slot latching relays latch on.
    The Coin Slot Cover Coil actuates to stop further coins being inserted into the coin slot.
    Either the Left or Right Safety latching relays latch on.
  3. The player plays the game with only two outcomes possible:
    1. The  Wand touches the Wire:
      1. The Game Over latching relays latch on.
        The Game Over flamelights are lit.
      2. The player returns the Wand to either end.
        Either the Left or Right Safety Buffer relays are actuated.
        The Reset relay is actuated, cutting power to the Coin Slot latching relays.
    2. The Wand touches the opposite end from which it started:
      1. Either the Left or Right Safety latching relays latch on.
        The Wire Enable relay is actuated so if the Wand touches the Wire it will be ignored.
        The Payout motor runs and the Payout lamp is lit.
      2. Five coins are dispensed and the Payout Complete switch is actuated, cutting power to the Coin Slot latching relays.
      3. The Payout motor continues to run until the Payout Complete switch returns to its initial position.
  4. The game is now reset ready for the next play.

Flamelights

The flamelights are non-Meccano items from LUXA Flame Lighting consisting of small fans which blow air up past orange halogen lamps into the silk ‘flames’.

A flamelight close-up, with the silk flame removed to reveal the halogen lamp
A flamelight close-up, with the silk flame removed to reveal the halogen lamp

Sign board

The sign board explains the operation of the game and is situated halfway between the two towers. In addition it hides the wiring between the towers and is where power enters from a separate power supply.

The sign board
The sign board

Construction

A full prototype of the right-hand tower was initially constructed to confirm that all mechanisms would be likely to work correctly in the finished model. Particular thought was given to providing easy access for maintenance, so the external casing of both towers can be easily removed.

All of the parts are new or refurbished Meccano, with all painted parts being stripped and repainted with either black or lavender enamel spray paint.

Built in June 2011