Coin Entry Horseshoe Magnet

[RameGoom]

I have a question for the experts. Is that magnet at the coin entry on an old slot really necessary? I believe it's there to reject slugs, which I probably won't be using in my machines.

The reason I'm asking is, I have a Jennings gooseneck that I'm working on, and the magnet is missing. The brass plate is there along with the screws, but no magnet. Seems to work fine without it.

Also, is it really necessary to have that little rod that pokes thru checks? One Jennings machine I have is missing that rod, the other has it.

Well, that was two questions, not one...

[marsonion]

I have a question for the experts. Is that magnet at the coin entry on an old slot really necessary? I believe it's there to reject slugs, which I probably won't be using in my machines.

The reason I'm asking is, I have a Jennings gooseneck that I'm working on, and the magnet is missing. The brass plate is there along with the screws, but no magnet. Seems to work fine without it.

Also, is it really necessary to have that little rod that pokes thru checks? One Jennings machine I have is missing that rod, the other has it.

Well, that was two questions, not one...

Neither the magnet nor the check separator are necessary for home play, unless you're a purist or an exonumia collector with lots of holey tokens you're eager to play with. On the other hand, I think everyone on this forum would prefer our vintage slots to be as mechanically and functionally authentic and complete as possible. That's probably why so many collectors here are obsessive about back doors and cash boxes, locks and keys, etc. But the slug rejection and check separation mechanisms are often very interesting and ingenious in their own right, and they had to perform a consistent and rigorous data processing function under very brutal conditions... that's why I hate to see them go missing because some previous "restorer" pitched them.

These days, of course, no slots-style gaming device requires any sort of token check or slug rejection mechanism. You'd even have trouble finding a slot machine that takes a coin in a modern casino. I can foresee a day when you'll have to somehow convince the machine that you've got a good credit rating before it'll let you spin its reels!

[RameGoom]

OK, then I guess the next question is, who carries those magnets? Any parts supplier that would have new, or used? That would make the coin system complete.

I imagine I could search some science store online and find the magnet, but just want the one that's supposed to fit, so an original would work.

[marsonion]

OK, then I guess the next question is, who carries those magnets? Any parts supplier that would have new, or used? That would make the coin system complete.

I imagine I could search some science store online and find the magnet, but just want the one that's supposed to fit, so an original would work.

A quick Google image search of "horseshoe magnets" reveals all sorts of shapes and sizes available from retail sources, even Home Depot. I don't know from Jennings goosenecks exactly what size and shape you're looking for, but someone else here on this forum might? One thing to be a little careful about these days is many modern magnets are of the rare earth (Neodymium) variety, and are very, very sticky... remember that the slug rejector magnet is intended to deflect the slug, not grab hold of it and never let go!

[randyjaco]

OK, then I guess the next question is, who carries those magnets? Any parts supplier that would have new, or used? That would make the coin system complete.

I imagine I could search some science store online and find the magnet, but just want the one that's supposed to fit, so an original would work.

In the dozen or so machines that I have had a chance to scrutinize the mech, I have yet to find a magnet of any type. I would also like to get the proper magnets. Does anyone have pictures of Jennings, Mills and Buckley magnets? I wouldn't know a OEM magnet if it stuck to me.

Randy

[RameGoom]

Found out something interesting today while experimenting with magnets. Apparently, the magnet serves two purposes; one, to detect and divert steel slugs, and two, to actually steer a coin via "Eddy Current".

Magnets are commonly used in mechanical coin comparitors in slots and vending machines. One of the main reasons is, when verifying correct coins, the magnet plays a role in slowing down the coin ever so slightly, to assure the comparitor of its weight and mass. Using a permanent magnet, a non-magnetic object passing between its north and south poles will develop what's called Eddy Current, which is essentially a magnetic pull placed upon that object - even though it's non magnetic.

So, today, I was trying to get my coin mechanism on this old Jennings machine to work properly with dimes. Seemed an awful lot of them were diverted back to the coin return. I could not explain why, until I installed a horseshoe magnet where it belonged. Oddly, the coin mechanism worked almost flawlessly, keeping the valid dimes in the correct path, to the mechanism, and not routing them to the coin return chute.

It appears that the magnet plays a role in preventing the valid coin from going back to the coin tray, by slightly diverting it into the slot that it belongs in. I've always heard that dimes are the most difficult coin to manage, and this may be one of the reasons!

So, check your magnets.

[marsonion]

In the dozen or so machines that I have had a chance to scrutinize the mech, I have yet to find a magnet of any type. I would also like to get the proper magnets. Does anyone have pictures of Jennings, Mills and Buckley magnets? I wouldn't know a OEM magnet if it stuck to me.

Randy

Here's the magnet on an old Mills FOK mech I've got...

[MONTI]

Maybe I missed it further up in this thread but what year and model Jennings are you dealing with?
Post a picture of the coin acceptance head if you would.

[RameGoom]

I'll post pictures in the morning. The magnets measure 2 in. long, 1 in. wide, and have an unusual curve ground onto one side of each pole. They're mounted into the acceptor, just outside the path of the coin return chute, with two screws and a brass cover plate. The rounded end of each pole is positioned toward the coin path if that makes any sense. And, when adjusted properly, the coin just misses the magnet as it passes thru the slot.

After some testing, I'm convinced the magnet serves two purposes; to detect and divert steel coins and to also verify and channel, via Eddy Current, a valid coin.

The slot I'm working on is a Jennings/Pace 10c "Butterfly" revamp, which is almost identical to my Jennings/Pace 25c "Twin Jackpot" revamp.

[marsonion]

Using a permanent magnet, a non-metallic object passing between its north and south poles will develop what's called Eddy Current, which is essentially a magnetic pull placed upon that object - even though it's non magnetic.
So, today, I was trying to get my coin mechanism on this old Jennings machine to work properly with dimes. Seemed an awful lot of them were diverted back to the coin return. I could not explain why, until I installed a horseshoe magnet where it belonged. Oddly, the coin mechanism worked almost flawlessly, keeping the valid dimes in the correct path, to the mechanism, and not routing them to the coin return chute.

In order to understand what you're saying here, I'm going to assume you mean "non-magnetic" rather than "non-metallic" in the first instance; I don't think any "eddy current" would be induced into a wooden nickel. With that proviso, I think you're saying that an instantaneous electromagnetic effect is induced into the coin as it passes through the magnetic field of the horseshoe, and that this in turn causes the coin to take a slightly different path than it would otherwise, maybe by "riding the rails" of the gooseneck or something. That's an interesting idea (and I wouldn't put it past any vintage coin-op design engineer's acumen) but I'd like to hear more about it. Are there any references to this particular invention/application patented or published anywhere? It's really an interesting and ingenious notion. For my part, years ago when I pulled a horseshoe magnet out of a dime machine (in order to play little steel washers as if they were dime trade checks, natch) it had no effect whatsoever upon the reject rate of the coins I played; i.e. no valid dimes (silver or otherwise) ever got rejected, irrespective of the presence or absence of the horseshoe-in-the-gooseneck, but all ferrous discs and washers did get rejected by the magnet, bigtime. That's just that one configuration on that particular make/model of coin entry, though-- I'd like to hear more about this eddy-current/induced electromagnetic coin deflection thing. Any more experts, please chime in!