Techno Stuff
How They Work - Score extra step

We went through this thing backwards, so we'll summarize in by itemizing the sequence in a forward direction:

1. The score extra step index coil is powered by the timer cams when a coin/credit is played. This releases the score extra step cam assembly, which due to a spring resets itself so the big pins are touching and both cams rotate.

2. The score extra step index coil loses power and the index arm drops against the cams:
   • if it falls into the small tooth cam, both cams are stopped and nothing else happens. The score extra step index switch is also open.

   • if it falls on the other cam, then the small tooth cam continues to rotate and the pulse switch generates a stream of pulses as the roller runs over the bumps. The score extra step index switch is held closed, so pulses are sent to the score extra step relay switch.

     if the score unit has stepped up, then the score extra step relay keeps itself powered and the pulses are passed on to the score unit step-up coil.

Other cam

surf club
the "other cam"

Here's the overhead view of the other cam. The score extra step index arm needs to land on those flat spots on the tops of the cam lobes.

Which lobe it stops on determines how many bumps the pulse switch runs over. As you can probably guess, the smaller the flat spot the more bumps.

It's possible for the scores to jump up five extra steps. For that to happen, the index arm must somehow land on that tiny flat spot on the top left lobe. The flat spot is not even as wide as the index arm. In addition, the game must have decided to step up the odds once already, so if by some miracle you hit that tiny flat spot at the same time the odds were already stepping up once, you will have the odds move six steps with one coin/credit played.

I expect this happens once every few years...

Operators

Stepping up one or two extra steps was reasonably frequent, and some operators didn't like that. I've seen the following operator modifications to disable the score extra step function:

• bend up the slip ring wipers from the cam assembly hub so the pulse switch is disconnected

• misadjust the score extra step relay switch so it can't close

• misadjust the score extra step index switch so it can't close

• misadjust the switch that powers the score extra step index coil, and make sure the index arm is on the small tooth cam

• cut the wires to the coil on the score extra step relay

• cut the wires to the score extra step index coil

• remove the score extra step relay coil, usually along with the coil frame

• hugh kown has seen a batch of machines where the score extra step index assembly was completely removed (coil, switches, slip ring wipers, and latch arm).

• and the most absurd one - remove the entire score extra step cam assembly from the mixer shaft and replace it with a piece of tubing (needed to preserve the spacing of mixer shaft components). This is a lot of work, and is completely unnecessary. Simply misadjusting the the score extra step relay switch so it can't close is good enough.

Patent

If you're a real glutton for incomprehensibility, here's the pdf of patent 2601524

overview | pulse generator | score extra step relay | summary