austin_dern (austin_dern) wrote,

I'm painting the room in a colourful way

Some time back the drop targets on our Tri Zone pinball machine broke. They're prone to breaking; Williams used a novel design for the drop targets that did not become an industry standard. Normally they're fixed by adjusting how well the copper contacts attached to the target touch a circuit board mounted to the frame. It has to be just hard enough and no harder, or gentler. This time, no amount of fiddling helped.

The problem turned out to be that the little U-shaped hook of the contacts had broken one of its legs off. So there'd be no contact across the circuit board whatever happened, and thus the game wouldn't work. There were replacement contacts for sale, from Marco's pinball supplies, which has everything you might ever need for any game. And after some time spent thinking about whether we could legitimately buy anything else so as to make the shipping costs not so great a fraction of the total sale, we got replacement contacts. Ones for all four drop targets, since someday they will all break.

This would give me a modest adventure in pinball machine repair, one without instructions so far as I knew. The first challenge: taking the drop target assembly apart. The drop target itself is a long rectangular slab most of which is below the playfield. There's a thin-diameter coil that connects the bottom of that to a metal bracket on the circuit board. This is what makes the thing slide down and stop smoothly, and pop back up sharply. There's a metal crossbar that keeps the drop target assembly from just falling down into the well of the machine the way the drop target assembly did when I removed it, losing all my sense of how the spring and the slab fit together. Oops.

Also it turns out the U-shaped contact didn't look like the pieces we got from Marco's because (a) you have to add a fold and a counter-fold into the legs of the U to reach from where the thing mounts on the drop target slab to where it touches the circuit board and (b) the particular broken U-shaped contact was itself a hacked-together repair job done by some forgotten earlier owner. So it didn't look anything like the new part, leaving me confused about how it was supposed to fit in place.

But I finally got the contact in place, I thought. And reattached the crossbar and then the spring (there wasn't a better way to do it) and found ... success! With the playfield lifted, the way a car hood does, for repairs, I could get that drop target to fall smoothly and to pop back up when it ought.

Not so much during actual play, with the playfield down and in place. The target would fall all right. It would pop up sluggishly, maybe not all the way. This turned out to be my fault: when I hooked the tiny-diameter spring back up, I'd looped a couple of coils around the bracket. That was easier than getting just the final hoop looped around and after all, what difference could it make? All the difference in the world, turns out. So there was a follow-up repair session and another feat of the drop target assembly falling into the well of the machine.

But with that done in that fiddlingly perfect ``correct'' way ... well, it's magnificent. The drop targets work, making the game much more interesting and much more playable. And I did it!

... Well, sometimes you knock down all the drop targets and it doesn't register right away. That's the normal problem with these targets, though. A little time fiddling with how the contacts touch the circuit boards should fix that.

Trivia: The average department store profit, in the late 20s, on a $2 sale would be between 4.6 and 8 cents. Source: Service and Style: How the American Department Store Fashioned the Middle Class, Jan Whitaker.

Currently Reading: The Day The World Discovered The Sun: An Extraordinary Story of Scientific Adventure and the Race to Track the Transit of Venus, Mark Anderson.

PS: two historic rides at Six Flags over Texas plus something for chefmongoose.


There'd been a show going on while we rode the carousel, and it broke up about as our ride ended. Here techs do ... tech stuff to the stage afterwards.


One of the park's oldest and most beloved rides: the Sombrero. It's a Trabant ride, with a theme that is exactly what the name suggests. It had the longest line of any non-roller-coaster that we went on, and we kept overhearing people talking about childhood memories of it.


La Vibora! The snake-themed bobsled coaster visible from the outside and defying all your mnemonics about red-touches-yellow versus red-touches-black.

Tags: pinball, six flags over texas

Posts from This Journal “six flags over texas” Tag

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