Project: Modifying the Soccer Kings "Goalie" Mechanism

The "Goalie" mechanism on the upper playfield of Soccer Kings is a simple design, using just two solenoids and a spring to allow for the game to have a semi-random attempt to block player shots on the goal. Unfortunately, the centering spring is usually broken, so the mechanism lists to one side. Here's how to fix it permanently.

Here is the back side of the mechanism. On this one, the original centering spring is still present, but is broken, so the mechansim flops over to one side.
Start by disassembling the mechanism. Mark the backing plate 3/8" from the outer edge, and 1 1/2" down from the top.
Centre punch and drill two 11/64" holes. These mounting holes should be in line with the pin on the back side of the moving part of the assembly (1 1/2" down from the top) and far enough out to the sides (3/8" from the edges) to allow room to work, but the exact location is not critical.
From the hardware store, obtain:
  • 2 Springs
  • 2 #8 Spacers (3/8" O.D. 1/8" height)
  • 2 #8 Lock Washers
  • 2 #8-32 x 3/8" Machine Screws
  • 2 #8-32 Hex Nuts
The springs need to be 1/4" diameter, and approximately 1 1/4" long. Larger diameter will rub on the backing plate. Too long and they will not work. Too short and they put too much tension on the mechanism. You need just enough spring tension to return the mechanism to the centre, but not so much that the solenoid coils have difficulty moving it. The limiting factor here will be finding a good hardware store with a selection of springs to choose from. Note that the springs shown here were ok except for being slightly too long, so they were shortened by removing some of the hook from the ends.
Assemble the mechanism. The screw and lock washer go on the front side (where the moving arm is).
Then the spacer, spring, and nut go on the back side. Tighten the nut enough to hold the spring in place.

Test your modified mechanism by hand. The moving arm should be relatively easy to move to the side, and should then return to the centre by itself.

David Gersic

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Last updated 31 January 2015