What principles are used behind a GOOD airhockey table?
I know you can get cheapy ones that have air but not much else.. More interested in the scoring side of things .. Whats a reliable way to detect a puck entry? Optical sounds dodgy, but so does press switches, too easy to not trip .. given the angles and different speeds the puck could come in at ..
Anyone know what the arcade machines use? Also, for the air system, what kind of system runs it? Never hear much of a pump/compressor noise from the arcade machines, so i'm guessing somethign small suffices there? Anyone know much about the sytsems used? Is it just a pump sealed into channels in a base, with a top overlaid with holes drilled through?
The air system is a simple squirell (sp?) cage on a 1750 RPM motor. Filter on the inlet side so the holes don't get full of crap. Doesn't take a large volume of air out the many holes to float a plastic puck. My tables all had a micro switch with a blade that the puck tripped to advance the score. Largest pain in the arse is the bottle caps, matchbooks, playing cards, etc that you have to fish out every week.
I havent seen one of these units since the mid 1980's. At the time I was 1/2 owner of an amusement centre - and we used to muck around with a LOT of different gear !
We bought a not working air hockey table for $100. Would have been early 70's vintage, and the electronics that controlled the scoring, game time etc didnt work.
The machine had a 117v blower that was mounted in a metal box, that had an air filter on the side that would have been about40cm x 20cm. (unfortunately a rat had died in this enclosure, which was why the thing had been sold so cheaply, as the smell that came through the air holes when the motor ran was putrid - it wasnt easy getting rid of the stench). I would estimate that the blower was about the size of a large home vaccum cleaner motor ?
The top of the table involves a thick sheet of wood, with many channels about 1cm x 1cm routed into it - these are directly under the rows of air holes. A sheet of laminex (playing surface) is glued over this wood sheet - and then the air holes are drilled/punched into it over the channels
The unit used a microswitch for the scoring (the microswitch had a trip wire on it - that the puck would hit as it rolled past) and there was a small solenoid in each end that would pull in to allow the puck to return back to the player, otherwise it would lock it in the end. Due to dirt etc - I wouldnt use an IR sensor.
Unfortunately the electronics in the thing were unknown type logic IC's that couldnt be obtained, and as a result - I got the job of designing a circuit to run the thing. In the end a 555 timer IC was used to set the game time - and for the scoring, 2 4017 ics were used. Each one ran 10 LEDS that were mounted under an existing bezel that had previously housed 6v bulbs.
A Relay was used to switch the mains to the blower. When the coin slide was pushed in, and then was pulled back, the game would start (this would stop it from being jammed in and allowing constant free play)
The game was not an outstanding earner - but it sat in the centre for about 8 years before it closed and CONSISTENTLY earned about $80 a week - unlike video games etc - there wasnt any expense involved in upgrading PCB's and such - and very little maintenance.