Side Rail Lock(s)
Right, this is really the reason this entire topic is on the site. The side rails are basically screwed into the head by turning a key round-n-round.
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| side rail locking nut |
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As the bolt rotates, it pulls the side rail into the head. The nut is mounted on a metal bracket, and the bracket is screwed into the head.
By this time, you have gotten into the back of the head, and you can see the bracket and nut. Your first idea is to remove the two screws fastening the bracket to the head, and then you can just spin the entire bracket to unscrew the nut.
Good idea, but the backglass and/or panel gets in the way. You could drill out this lock, but I've never found a source for these locks, so if you do, you will probably wind up replacing the entire lock with a big carriage bolt or some ofther fastener. It may be possible to use a standard lock and some threaded rod to make the lock, but the threads used on the nut are course, and the threads on standard locks are usually fine, so be prepared to replace the nut as well.
The easiest solution is the break that little metal cage that is wrapped around the nut (the nuts are called "cage nuts").
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| break the weak point |
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You stick a long screwdriver into the gap between the cage and the nut and twist. By using larger/smaller screwdriver heads, you'll eventually snap the cage, and then you can unscrew the nut.
Just be careful how much forward pressure you apply...if the screwdriver slips, you'll poke it into the backglass - usually with suboptimal results.
Once you get one side rail out, you can slide out the glass. Try and pull the glass away from the head when sliding to minimize scraping off the ink. Initially this is hard to do until you can grab the glass edge. you can sometimes remove the mounting bracket, push the backglass forward from the back using the hole in the panel where the mounting bracket lives. Another approach is to use a suction cup or duct tape on the glass front and pull the glass away from the head while sliding it.
If you can't avoid pressing the backglass against the head, then slide some paper between the glass and the side of head, and let the paper move with the glass. What you are trying to avoid is the ink side of the glass contacting the wood.
If your backglass is flaking, don't even try to slide it out until you remove both side rails or can successfully keep the back of the glass away from the head. Depending on the game type, though, one side or the other may be impossible to get to. After you pull the backglass, you can unscrew the bracket on the other side rail and spin it off.
Once you have the rail off, you can pull out the lock cylinder and remove the lock pins by just pulling them out with pliers. Then you can just turn the lock with a screwdriver in the future. You'll need to patch up/make another cage for the nut, or replace the nut (if you are lucky you may find them at a local hardware store). Alternatively, you can just screw the nut back on from the back and leave the side alone, but I'd only do this on a backglass that has been sealed so you can't scrape off the ink when sliding it out.
Note, if you do this, just be careful who may try and get into the machine. When I was a kid, I broke into a pinball machine we had in the basement and removed the lock pins. I then thought the machine would be a great place to hide all those things that parents shouldn't find. Worked great for a few years until a friend of the family with a big ring of keys thought he would play GI Joe Junior Locksmith. Naturally, the first key he tried turned the lock. Fortunately, the bottle of 8 year old scotch could have gotten into a 18 year old machine before my time :-)
See also the charlie carroll method.
