Killing one for the Cause

And so you have this idea for a project in your head, and many hours pass by browsing the internets and even the massive paper catalogue of Conrad Electronic. Learning about components, their sources and their prices.

On Marktplaats I came across an defunct early eighties slotmachine for a silly low price. This particular machine was built by Marian Electronics Ltd. in February 1981 and the game was called Hold It. That was a nice start to harvest a couple of these typical slotmachine buttons from and since this old machine had four reels; these could possibly be reused too.

Pictures of the donor machine for sale The donor machine <em>Hold it</em> before I started removing stuff

Picked it up and started to disassemble the poor machine. With heavily corroded PCB’s and some burned components it was obviously dead although I am not sure what it would have took te repair it. What I paid was well worth one or two buttons, so I swiftly removed what I needed and left the remainder of the machine in an even more miserable state than I found it (and a colleague wanted to adopt the housing).

Opened machine from the back showing the solenoid valves that stop the (red plastic) wheels Serial number 16825 as build by Marian Electronics Ltd A couple of clearly burned resistors might have been a culprit for retering this machine Heavy corrosion of the printed circuit boards seems to have been &ldquo;repaired&rdquo; in the past

Hold It used mostly incandescent and fluorescent lighting, so most of that was left inside or removed for another colleague that restores pinball machines. The reels proved to be of a different (even older) type than I envisioned for my project. This older machine used a powerful 50V motor, driving mechanical disc by a rubber band. Solenoid valves stop the mechanical discs (and thus the reels of the slotmachine) in their required position, while holes in this discs are read by photosensors to determine and/or verify the correct position.

For my project I wanted to play with stepper motors driving the individual reels, so most of the mechanical stuff around the reels will be removed. But still, in addition to all the good buttons and a couple of 7-segment LED’s, I could harvest this 4 plastic reels that will be reused on my tribute slotmachine.