The hopper Arc switches

[OldReno]

The hopper Arc switches.

Sometimes hoppers will have a set of switches on the back side of the payboard, which are operated by the step up arm.
They are normally open, and close when the step up arm physically pushes them closed.
Actually I don't know what they are called, or even if that is their stated function, however I have noticed from trial and error that by adjusting them properly, it does seem to cut down on the amount of arc-ing that happens on your payboard.
If you see little half-moons at the ends of your hopper pay segments, then you may want to adjust your arc switches.
They should fully open AFTER the inboard wipers step fully off the pay segments.
You should be able to adjust visually.
The problem with arcing is that it will eventually force you to adjust your hopper board to make up for the missing foil, and will find that often your machine is paying a coin short on some pays.
My understanding is that they help dissipate some of the energy from collapsing current at the end of pays as the payout relay and other coils de-energize. That energy has to go somewhere, and rather than through the payboard (melting your pay segments) the arc switches dissipate that energy, as long as the open AFTER the pay fingers leave the hot pay segment on the payboard.

Now it may very well be that I'm full of BullS#!t, too, because I've never run across any info on these guys.
But I thought I'd post anyway, because perhaps some other old timers here can help us all out to understand this circuitry.
Thanks.

[Op-Bell]

You explained it right, you just didn't quite get it. The contact shorts out the wiper board to keep the win relay held in as long as there's a coin on the ramp. That does several things. One, it ensures the motor keeps running until the coin is driven all the way out. Two, because the wipers move when the coin leaves the ramp and not when it enters, it provides an alternative path and the wiper is never relied on to pass current while it's moving. And three, as you say, when it's properly adjusted it makes sure the current doesn't break until after the wiper steps off the end of the track, so avoiding arcs and sparks that could damage it. It's always the last contact to break that gets the spark.

The fat resistor across the relay coil also serves a spark suppressor, and slightly delays the relay dropping out to make sure it doesn't chatter and arc as the hopper steps.

[OldReno]

@Op-Bell,
That's really an awesome description.
Thank you for sharing it. Will re-read your post several times....
Very nice.

[frenchmarky]

Speaking of these burned payout traces...

Awhile back I had to do a little fixing of a couple of the high-occurence payout traces on my 873 (like 2 coins and 5 coins, something like that).  This was where the end of the trace had been burned off a little from heavy use or as you say, the misadjusted arc switches.  It even degraded the bakelite a bit after the arc points and started to pit it there.  All I did was sort of tack onto the ends of the burned traces with solder, then filled in any remaining bakelite pit with superglue and then finally carefully leveled off the repair with a fine file.  Anyway I basically HAD to do this as otherwise it was impossible to adjust the whole trace board to where every payout always paid out correctly.  If left unfixed I'd have to compensate the position of the board so that those paid right, but that threw the board out of whack to where it could end up skipping onto a false additional payout after the first one was supposed to end.  Or vice versa.  That adjusting was driving me insane until I realized okay gonna have to do something to these trace burns or it's just never going to work right.  I doubt I'm the only guy in here who is driven crazy unless something like a slot machine pays out perfectly every time like it's supposed to, but I hope some of you are like this too  : )

Are there better ways to fix this sort of thing with burned trace ends than what I did?  I also adjusted the switches as the manual suggested to prevent future arcing on the payout traces.

[OldReno]

Other than replacing the board, that's what I'd do.  Sounds like you did ok.  Is it working fine?
If you had some fine thin copper foil, you might be able to glue them down and then solder, but sounds like you did good as it is.
Cool!

[frenchmarky]

Once in a blue moon it might pay an faulty payout, where it manages to eke past the end of the correct pay and pays a few more, but nothing like before the fix.  I might crack it open again sometime and try tweaking the board position again but invariably it seems to just cause a different but similar problem.  Part of it is the design of the 873 and other multiline payers where they are prone to this just by how the pays are layed out on the board traces.  A correct payout can happen, then if you pulse the counter one more time by hand, bingo, it ends up on another (false) pay, and that's what's happening without the manual pulse sometimes... I don't think this kinda thing can't happen on a simpler machine like a 1-line one.  I should probably pull the darn thing out one more time and tweak the wiper positions a little more too and get them lined up absolutely perfectly.

[OldReno]

As I recall the 873 is a pretty complex payboard.  You might get out your Xacto knife and try a little trimming on those edges.
Otherwise a very impressive job I would think.  Good at ya!

[frenchmarky]

Thanks!  I also shaved the bottoms of the wiper contact points a little to make them skinnier vs. the spaces between the traces.  That also helped.  This was because the contacts were well worn down to 'flat rounds' instead of a small point of contact like a new point, so they were more likely to bridge over to the false payout depending on the pay circuit in play, timing, minor slop in all the old parts etc.  I got a new wiper blade but found out it doesn't really fit right on this old of an 873 unless I started hacking at it or the mounting, so if I get out of my perpetual lazy mood I might try pulling all the new contacts out and transferring them to the old wiper, but that is beyond my level of initiative right now, maybe later.  Right now it is working good enough, doesn't bother me anymore with constant pay screwups.