Replacing wiper finger contacts
By: michael sands - http://www.sandsmuseum.com
Games affected: all
As discussed in the parts that wear material, the contacts on wiper fingers will wear down over time, and the contact itself doesn't seem to be available. In the old days, you could buy replacement wiper fingers and rivet them in. These aren't the old days.
Michael Sands does a lot of restoration work on older machines, and has frequently been faced with worn out parts that are unavailable. Recently, he ran across a worn down finger on a mixer rotor in a silver sails, and he kindly documented the solution and passed it over for posting.
|Shine up the metal on the arm. Notice the contact is half gone. Cut off the contact, leaving as much of the arm as possible. The arm bends and acts like a leaf spring, pressing the contact against the rivets.|
|Cut off the contacts from a parts machine. Keep the length as short as possible because a double thickness of metal will not have the same spring. The top tip is the contact side while the bottom is the back side of the contact arm. Shine up the back side. The bottom contact is too long and should be shortened.|
|Here the clamp is holding the shiny portion of the arm against the shiny back side of the contact. It is important to keep the metal clean so the solder flux and solder will flow between the two pieces of metal.|
|Place some flux near the edge, between the two pieces of metal. Then heat the solder on the iron and touch it to the metal. It should quickly flow between the two pieces, locking them in place. I used TIX, a silver solder with 50.000 pounds per square inch holding power. Regular solder will probably be fine.|
|Here is the finished tip, polished and ready to make contact.|