(Topic ID: 335908)

EM Pop Bumper Switch Gaps?

By mdo1998

11 months ago


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Topic Stats

  • 34 posts
  • 13 Pinsiders participating
  • Latest reply 10 months ago by mdo1998
  • Topic is favorited by 2 Pinsiders

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#1 11 months ago

Anyone have any advice regarding ideal switch gaps for EM Pinball’s, would like to see if my mid 70’s machines are set correctly.

#2 11 months ago

Gap them and play a game. If they fire when other stuff is hit or when the flippers flip they're gapped too closely. If they don't fire when a ball rolls over the skirt they're gapped too far apart. Trial and error until they fire perfectly. I think 1/16" is a good starting point.

#3 11 months ago

Mine are working, I was thinking more about the power, if certain gaps were likely to increase or decrease their power.

Matt

#4 11 months ago

That's kind of a 2nd level effect. If the switch is gapped too close, it's possible that the pop bumper will fire when the ball is barely under the ring. A wider gap would let the ball get further under the bumper before it fires giving the dropping ring more contact and a better kick on the ball. It can be a subtle adjustment.

/Mark

#5 11 months ago

What EM? Some Williams went to DC for the pops and slings and they kick like the dickens when set up right and the pops mechanisms and switches are clean.

#6 11 months ago

Power for the pops on some machines is fed through the relay that gets energized when the switch triggers. Cleaning, gapping and filing those large contacts may be in order. Looks like yours with DC pops just feed through the switch without a relay involved.

A pop rebuild kit might also help if linkages are worn, coil sleeve is old, etc.

#7 11 months ago

It’s a Gottlieb Sure Shot, just finished installing the PBR rebuild kit, and don’t see any meaningful improvement, the bumpers are just weak. I’ll do some testing with different gaps and see if anything helps, the balance of the bumpers seems fine. Nothing broken or cracked.

#8 11 months ago

Anyone ever notice an issue with decreased power due to spring strength? I’ve adjusted the contacts on the Pop Bumpers and the their associated relays, and the two Pop Bumpers where I have NOT performed a PBR rebuild are working very well, the one with the rebuild kit installed remains sluggish, pushing down the rings manually I noticed the original two have far less spring pressure to overcome on the down stroke as compared to the unit with the rebuild, I’m going to put the original spring back in tomorrow, and see what happens, just wondering if anyone has seen springs as an issue in their experience.

#9 11 months ago

Could be that your coil on the sluggish pop has a higher resistance to that on one of the others. Try un-soldering the 2 wires on the sluggish one and a faster one and compare the readings with a multi-meter. If one is obviously high, replace it. PBR sell - or certainly used to, higher powered coils for pop bumpers ( they had a red wrapper on them). So if you have a bad one, maybe upgrade the lot and have better performance across the board. Or playfield even
I would also clean/file all the high current switches in the pop circuit so that you are getting a decent current feed too.

#10 11 months ago

Another way to find out what if any part is at fault, is to swap parts between the good and bad pop bumpers

#11 11 months ago

Did anyone mention to make sure the EOS switch is gapped to allow a full stroke of the armature?

https://pinside.com/pinball/forum/topic/em-pinball-circuits-basics-to-not-so-basic/page/3

#12 11 months ago
Quoted from Garrett:

Did anyone mention to make sure the EOS switch is gapped to allow a full stroke of the armature?
https://pinside.com/pinball/forum/topic/em-pinball-circuits-basics-to-not-so-basic/page/3

EOS on a pop bumper? I mentioned making sure the switch is clean in post 5.

#13 11 months ago

You could move the wires to "High Tap" on the transformer.

#14 11 months ago
Quoted from schudel5:

EOS on a pop bumper?

Yes, pop bumpers do have EOS switches.
Sometimes I think they cause more harm than good but they do have them.
Some particularly weak bumpers can benefit from an adjustment allowing it to open at the very bottom of the stroke, but be careful not to overdo it or you could cause your coil to lock on.

#15 11 months ago

To clarify, AC powered pop bumpers are usually powered by relays that send power to the pop bumper coils. The relay fires when the spoon switch under the pop bumper closes and remains active until the normally closed EOS switch under the pop bumper opens. It's a common lock in circuit that keeps the pop bumper active through its entire stroke.

DC powered pop bumpers use only the spoon switch below the pop bumper to send DC power to the pop bumper coil. When the ball rolls away the switch opens and power to the pop bumper coil is cut. The normally open switch at the bottom of the pop bumper fires a point relay to award points, fire the chime, etc.

#16 11 months ago

Part of the obvious issue here you are expecting your Gottlieb’s to play like your Williams games, that’s never going to happen here. Especially when comparing an Aztec & Big Deal play to a Sure Shot. I restore and clean all my games the same, which is very through. Gottlieb games are just going to appear slow compared to your Williams. Everyone who plays my machines notices this when bouncing from a Williams to a Gottlieb.

#17 11 months ago
Quoted from Mikala:

Part of the obvious issue here you are expecting your Gottlieb’s to play like your Williams games, that’s never going to happen here. Especially when comparing an Aztec & Big Deal play to a Sure Shot. I restore and clean all my games the same, which is very through. Gottlieb games are just going to appear slow compared to your Williams. Everyone who plays my machines notices this when bouncing from a Williams to a Gottlieb.

A standard Gottlieb against a Williams, yes, I'd agree. But, and assuming that pop mechs are as good as can be, etc then by using higher powered coils from PBR, or, by removing a couple of turns off a pop coil : http://www.pinrepair.com/em/index3.htm#perform works very well (in my experience anyway) on Gottlieb machines. High tap? Can't say I've tried that route only as I'd be bothered about increasing power to a machine that might already be receiving the correct input voltage? Would that do more harm than good?

#18 11 months ago
Quoted from Mikala:

Part of the obvious issue here you are expecting your Gottlieb’s to play like your Williams games, that’s never going to happen here. Especially when comparing an Aztec & Big Deal play to a Sure Shot. I restore and clean all my games the same, which is very through. Gottlieb games are just going to appear slow compared to your Williams. Everyone who plays my machines notices this when bouncing from a Williams to a Gottlieb.

This has been my experince as well.

#19 11 months ago
Quoted from 2manypins:

You could move the wires to "High Tap" on the transformer.

Nah, don't do that. Find and fix the problem. Needlessly high-tapping a game isn't a good thing.

#20 11 months ago
Quoted from Vintage-Pinball:

High tap? Can't say I've tried that route only as I'd be bothered about increasing power to a machine that might already be receiving the correct input voltage? Would that do more harm than good?

Yes, you are correct. If the line voltage is adequate, don't high-tap. It's much better to install hot coils if you must, or remove about 40 turns from pop bumper coils to make them stronger. High-tapping stresses non game play components, such as steppers and score reels. You should only do it in situations where the line voltage is low, but in those rare cases, I'd just use a variac or a buck/boost transformer to bring the voltage up.

#21 11 months ago

Something else to consider is the ring and shaft. Later games used a longer shaft. I’ve experienced weak pops when a late 70’s pop assembly has the ring and shaft replaced with the shorter unit. It might be worth it the see what your machine has installed.

#22 11 months ago
Quoted from kangourou:

Here is a pic. Left is for "BEFORE Surf Champ" and Right is for "AFTER Surf Champ". Dimensions in millimeters.
A4754 is a substitute for A1316.
The solution : Buy a A4754 and put some washers.
http://www.pbresource.com/pfbumpb.htm
[quoted image]

https://o.pinside.com/f/67/23/f6723fbc90318d0c7eff92dd7f632315f8ab49fa.jpg

#23 11 months ago

Looking into it more, Sure Shot comes before Surf Champ, so I’m probably wrong and it requires the shorter shaft anyway.

#24 11 months ago

Thanks everyone for the guidance as always. I think part of the issue is the Gottlieb vs. Williams topic, but with one sluggish as compared to the other two within Sure Shot clearly something on-going. I’m going to swap the coils and see what that does as I’ve set the switches and relays for all in similar fashion.

#25 11 months ago

PS going to start with that EOS switch, I had thought that was a point scoring switch only, if like on a flipper it’s cutting the power, this may be the issue. Thanks everyone.

#26 11 months ago

Helpful Pinsiders, I’ve noticed the two EOS switches for the two upper Pop Bumpers only have contact pads on the top portion of the switch; these two bumpers run from a single relay, whereas the sluggish Pop Bumper run from a different relay, has a contact pad on each of the switch blades of the EOS switch, I would think this would be a better connection, and perform better, but performance is not better, any thoughts, any impact or cause of the sluggishness? Picture below of one of the single pad switches. In addition the sluggish Pop Bumper had the largest travel time to the EOS switch, and the smallest gap, so this setting would seem not to be the issue.

IMG_4135 (resized).jpegIMG_4135 (resized).jpeg
#27 11 months ago

What does the coil paper look like on the problem pop? Burnt or not?

The contact pads should be there for best long term operation. You can get new leaf switches or just the contatcs and solder them in. Some people will just blob solder in the hole where the pad once was.

#28 11 months ago

The paper wrap looks fine, and the switches missing the contacts pads are the better two performing Pop’s, so I guess I’ll leave as is, was just wondering if lack of a pad would improve performance as that’s what I’m seeing, although I suspect not related. Just a coincidence.

#29 10 months ago

It's either electrical or a mechanical issue. If you've inspected the coil sleeve, plunger, correct ring/rod, etc then it must be an electrical issue. I'd look at the contact points in its relay. The larger contacts are those that supply current to the coil; try carefully filing them clean to remove any pits caused from arching so that they are supplying maximum current.

Even if the wrapper is sound I'd still take 5 minutes to deseolder the wires on a good coil and compare against the sluggish one to at least eliminate the possibility of it being out of range.

As for the EOS switch, it's designed to have a contact, so I'd just fit a new one. Personally, I wouldn't use a blob of solder because the high current perhaps might melt it. And look at how those on the faster pops are set up against the slow one and adjust it to match.

#30 10 months ago

Thanks, I’ll do that, I’ll recheck those areas.

#31 10 months ago

I don’t have that schematic, but if there’s an end of stroke switch, then there’s also a pair of hold contacts on the relay, so those should be inspected as well. I have definitely replaced my share of relay contacts for pop bumpers, both the high current ones and the hold circuit ones. You’ll probably find them burned or totally missing.

Dave

#32 10 months ago

Thank you Dave, greatly appreciated.

#33 10 months ago

I would assume you have moved the pop assemblies by hand to feel for any noticelable difference in slop or friction? Is the pop body still in good condition or is it starting to wear through?

#34 10 months ago

I have not fully disassembled the pop units, but no damage is visible nor do I feel any abnormal resistance when disconnected from the under playfield connections, all three Pops move easily without snags. As I’ve rebuilt them already, I’m going to focus on the switches driven by the relay that drives the sluggish Pop.

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