Yeesh...Yea, it COULD be done, but it would probably cost you more to build one than to buy one. You'd have to build a ramp (Which would be no small feat itself), setup the point zones triggers, rig up either a pre-made "CPU" or program your own...Sounds like it would be more trouble to build one that it's worth.
Funny this was mentioned....
My brother and I actually WERE going to try this. We got measurements, drew up some sketches, etc.
That's when we began pricing wood, materials, labor, and looking at the actual scope of the project.
Needless to say, it never got off the ground...
Our project took about three steps before we abandoned it. Here they are for anyone else who would like to try:
1. We went to a local arcade here and measured a skee-ball unit. (The owner is a friend of ours, so he let us climb on it...) The dimensions are flat-out ridiculous. Not all machines are the same, but the one we looked at was HUGE. And when I say huge, I mean, stupid big. The ramp, before getting to the scoring platform, is just over 8 feet in length. Then you've got to measure the actual platform, which is just under 5 feet, including the pedestal for the scoring display. Thickness is another issue. 3/4" MDF, similar to a lot of people's cabinets, just won't cut it here. That platform was nearly 3 inches thick. I don't know of any lumberyards that carry 8 feet by 4 feet by 3 inches in any kind of wood.
2. Most skees, though not all of the newer ones, contain a significant amount of steel (or aluminum, depending on the year of the unit.) According to our friend, he has to actually contract a machine shop to get him parts for the unit. That's pretty difficult to do. Of course, you wouldn't have to go the authentic route, but we really wanted to make it as close to original as possible.
3. The unit needed to be engineered to disassemble and reassemble quickly. Again, pretty tough to do, considering the part that couldn't be reduced in size is the ramp.
Anyway, we gave up. I still have a dream to build my own skee, but with my first child on the way, my wife pretty much says forget about any other arcade projects. I'll try to find our old plans and maybe post them if anyone else is interested in trying this.