Gottlieb Volcano system 80, model 667

I've been having two issues with the subway kicker:

• Sometimes, but rarely, it takes several attempts for the kicker to get the ball back onto the play-field
• The ball almost always goes down the drain or very close to going down the drain when it shoots back onto the play-field

When I examined it, I discovered somebody installed an A-19300 coil (7.8 ohms) on the subway kicker and the fire-pit. The schematic shows that these coils should be A-4893 (2.1 ohms). So I replaced them both with the correct coils and sleeves from PBR. (The fire-pit was also ejecting balls down the drain, but the correct solenoid coil fixed this and it's consistently knocking the ball into the pop bumper instead of the drain.)

Now the ball is shooting out of the subway harder and mostly going towards the right flipper as it should. However, during play, I got a multi-ball and 1-2-3... all three balls shot straight down the drain.

It also seems like this solenoid is not always firing as hard as it should. The other issue where sometimes it's not able to kick the ball all the way out is still happening occasionally. The ball rolls back down and when this happens, it takes a couple more attempts before it's ejected.

Took the metal cover off and can see what's happening. When the ball stays in the groove between the two rails, it shoots out where it should. When the problem happens, the ball leaves the groove of the track and exits the play-field opening from on top of the left side track rail, which leads it straight down the drain.

There does not seem to be any adjustments in any of the mechanisms here, short of bending metal or drilling new holes. I am just not understanding what's causing this problem. It looks like the hammer might be extending too far and hitting the ball off to the side instead of keeping it centered. However, this too has no adjustments. The solenoid plunger stop is about 5/16" long, but I don't know what it's supposed to be.

I still have absolutely no idea why sometimes it shoots out like a bullet, and other times it takes two or three attempts to eject one ball. And no clue if it's coming out of the track groove because it's being hit too far, too hard, or too soft.

What I've done:

• Cleaned and waxed the metal tracks, guides, etc.
• Buffed, cleaned, and waxed the hammer head that hits the ball
• Slightly bent the metal side walls to help guide the ball up the center and stay in the groove. (I left a little clearance because I did not want the ball getting pinched.) EDIT: I only did this on the upper end near to where the ball exits.

It's still not working consistently.

The video and photo shows the ball coming out of the groove and onto the left rail while being ejected.

Any tips, hints, clues appreciated.

Thank you!

out of the groove

EDIT: Read this entire thread to the end since there are a few red herrings in between as my idea of the theory-of-operation evolves.

Thank you for your response.

I have an original full Volcano manual and there's nothing in there about adjusting the rails.

I was reading it online someplace a few weeks ago but can't remember where.

On full stroke, it's not perpendicular... it's past perpendicular. But the striker arm is very thick metal and nothing is going to bend. The solenoid itself has no adjustments other than to make the coil tight. The assembly is mounted on a long bracket and in order to rotate it enough to make the hammer perpendicular, it would have to be moved large amounts on the order of an inch or so.

Unless the solenoid plunger stop was changed and it's not the correct one? I don't know where to find out what stop it's supposed to have. But if I can get the plunger to stop about ⅛" short, it should get the hammer stop position close to perpendicular.

I'm hoping I'm missing something simple, because getting this to hit perpendicular is going to require a lot of modifications.

Otherwise, I am at a complete loss.

Any thoughts on why it sometime does not seem to fire strongly enough? Could a failing transistor cause this? Although all of mine were tested last time I worked on driver board. Then again, maybe it's just shooting the ball sideways at those times?

No, those parts are original and not very worn. The 5/16" stop is still riveted and when I measured it, noticed very little wear.

IMG_8968 (resized).JPG

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To get the hammer to stop perpendicular would require a screw hole in the playfield exit, where there is no play-field. The assembly would have to rotate so much that it may interfere with the cabinet itself. I just can't see why this is like this.

IMG_8976 (resized).JPG

You are correct. I tried to shorten the stroke of the solenoid by slightly bending the plunger-stop bracket. Disaster... no balls were kicked up... just kept bouncing up and down the ramp. I was able to get that back the way it started.

None. That was first thing attempted. They are slotted in the long direction, not in the "making the groove wider" direction. Using those slots I have the metal rails even with the play-field surface, no gaps. No idea if this is correct. If you make the groove wider then the bottom of the ball is going to wear into the edge of the play-field even more. The groove narrows to bring the bottom of the ball up to even with the play-field surface.

Actually, this is the only progress made. I observed that the ball was not sitting in the groove all the way because the switch arm was pushing and holding the ball to the side... this was causing the kick-up failures because the hammer was not striking the ball squarely. The switch arm was very sloppy and out of whack... I tightened and adjusted it to be like the others. It was difficult, but now the ball seems to be getting down into the groove without the switch arm wire interfering as much... not perfect and it still failed a few times. This is a difficult problem because it can only be tested in the down position and only be tweaked in the up position... endless trial/error with little progress.

And the original issue where the ball just shoots out wherever and however it wants ... no progress at all!

I even totally took everything apart... the rails were polished like mirrors.

Maybe I need to go back and bend the side-walls inward some more near the bottom of the well? Keep the space narrow enough from top to bottom so that the ball is forced to stay on the center of the track? And on the other hand, maybe this is the problem... the ball is deflecting off the opposite wall when it ejects? LOL!!

I have no idea!

Yes, side to side level. Front to back slight slope forward.

I found it!

I was previously too focused on narrowing the exit-end of the sidewalls to "funnel" the ball back into the groove. Instead I should have focused on keeping the ball in the groove from start to finish. Even though I also had a problem with the switch, both problems (ejection strength and direction) were caused by this:

The sidewall on the right side (of the photo and play-field) shows a dark wear line. The video below shows how the ball was striking this wall immediately when kicked, and getting pushed up out of the groove and towards the left (more drain). When you hear a click in the video, that's when the ball hits the edge of the sidewall; and you can see a gap where the ball is pushed up out of the groove.

After making some adjustments to how these walls are bent, maybe now ~1/16" clearance on both sides of the ball while it's in the groove over entire travel, it stays in the groove during ejection. The spacing might not even be critical as long as those metal side walls aren't pushing the ball out of the groove.

I used a strong automotive extension magnet (magnet on a stick) to hold and move the ball up and down the groove while the play-field was up.

sidewall pushing ball out of groove

It hits exactly where the track groove is pointing, which is the RH flipper.

Also verify subway kicker is using the proper solenoid coil. Mine was replaced with something else - I put original part number back (A-4893) so it shoots out harder too.

Not really. The one sidewall was bent too far towards the center-line, which knocked the ball out of the groove whenever it was kicked. If it's not in the groove, its trajectory will be wrong. So that sidewall needed to come outward. At that point, I adjusted the sidewalls to make sure the ball rides in the groove with very minimal, but equal, clearance on both sides. As per video, use a ball on a magnet stick with the play-field up and the flapper door removed to verify clearances.

PinballAir and Robotworkshop - Here is an illustration of the issue and solution.

Ball was striking the sidewall on the right, deflecting ball towards the left, coming up out of the groove, and riding up on top of the left rail giving it an unpredictable path that led to the drain more often.

Adjust the sidewalls parallel to track with just enough clearance to eliminate any ball contact while ball is in the groove.

Volcano Subway Kicker path

EDIT: Not full solution. Image should be labeled "Not Good" and "Almost - Not Quite"

Look for wear lines. I had very deep and heavy ½-¾" long wear lines on the RH sidewall where the ball was impacting & sliding for many years (see white arrow in my photo above). Whenever the ball took several kicks to eject, you could hear that tong sound of the vibrating metal (in my video above it's the impact clicking) ... I always wondered what was causing that before I discovered this issue.

Here's the Gottlieb On Target technical newsletter from July/August 1981 that explains in great detail all the necessary Volcano subway adjustments on page 3:

https://web.archive.org/web/20190926012714/http://www.ionpool.net/arcade/on_target/ontarget_julyaug81.pdf

Notice steps 4 and 5:

"4. ... Insure the ball does not hit the side guides. 5. ... The ball should be kicked to the right flipper. If the ball drains between the flippers, pull the left ball guide slightly toward the kicker track."

page 3 of July/Aug 1981 On Target newsletter

I was still getting the occasional ball drain so I went back to the service bulletin to review and readjust.

This is such a tedious process.

At one point, I adjusted the side-guides too close to each other, which caused the ball to bounce between them and never shoot up hard enough to leave the subway. However, when another ball was pushing up against the ball in the subway, it prevented this bounce and it would shoot out hard.

So I ended up pushing the guides farther apart on the bottom end and narrower at the top. I get a lot less drains, but the ball wants to hit the RH slingshot instead of the RH flipper as intended.

I am disappointed in how difficult and tedious these adjustments can be. Too much guesswork and I practically have to do full disassembly to make each and every adjustment.

The part where step 4 says "Insure the ball does not hit the side-guides" is impossible. I think it means to say "Insure the ball does not 'touch' the side-guides when in the track". The kicker knocks the ball to the right and it always hits the side guide no matter what adjustment is made. Other than moving the guides around, the tech bulletin is not much help. I wish they would have included measurements to help with positioning everything properly.

The part where step 2 says to "pull the right guide as far away from the track as possible" is very unhelpful. There is almost no adjustment in the screws and I could literally bend this guide any way I want. How far away from the centerline of the track would be nice to know.

After a lot of experimentation, this new drawing is how I ended up. The guides are "funneling" the ball. There is no ball contact when ball is in the groove, but the way the ball is struck, there is inevitable ball contact with the guides... there has to be or the guides could be removed entirely.

Gottlieb Subway Kicker-2 (resized).png

As of now, I am getting mostly hard contact with RH slingshot. Occasionally contact with RH flipper, but still sometimes a drain.

This is my dilemma. If I adjust to aim more towards the RH flipper, it's moving it closer to the drain so I believe I am going to get more drains.

I do not know what mental misconception about the physics of this device is preventing me from finding the sweet spot.

I hit it again. This time trying to follow the steps in the newsletter.

"1. Lift & support playfield."

done.

"2. Pull the right guide away from the subway kicker track as far as possible."

Very subjective! There is almost zero play in the screws but you can bend this a lot in either direction. I removed my funneling strategy and lined it up more with the outside edge of the track. The ball is kicked towards this right guide no matter what you do. It seems that the swing of the kicker initially pushes the ball to the right and it glances off the right guide. I took some slow motion video and there are no possible adjustments that can prevent this. However, moving the right guide towards the track is definitely the wrong thing to do as this glancing blow becomes so hard the ball will not exit the subway.

"3. Loosen the ball trough and move OVER the subway kicker track as far as possible."

Ok. This one depends on how the playfield was constructed. Why would it be constructed with slotted holes in the first place if the procedure is to move it all the way over as far as it goes? Just build it that way in the first place. Slots imply that you may need to move it left or right, not all the way over to one side.

"4. Set the playfield down and test. Watch that the ball is dropped onto the center of the subway kicker track on top of the rollover switch. ...."

So what if it doesn't? Since the track is moved all the way over, there is no way to fix it if it doesn't. I am not even sure how or why this matters. Once the ball is dropped, it settles into the center of the groove before it's kicked anyway. Seems like a moot point.

"4. .... The ball will be kicked onto the playfield. Insure that the ball does not hit the side guides."

Impossible. If the ball didn't hit the side guides, then you wouldn't need the side guides. Maybe they mean make sure it's doesn't rub on them during travel in the track? Again, no explanation about what to do in case this test fails.

"5. Ball should be kicked to the right flipper. If the ball drains, pulls the left ball guide SLIGHTLY towards the track."

I decided to "start over" and moved the left guide all the way over to the left too. It's counter-intuitive, but adding all this extra clearance, did not cause the ball to drain more. I did follow the instructions and slightly moved the left guide inward to push the ball more towards the right flipper.

Problems/Causes/Solutions:

• Ball is draining all the time or most of the time. It seems that the ball is riding up out of the groove and up onto the left side track. The guides are completely out of whack and aiming the ball way too far to the left.

• Ball is unable to leave the subway. It is kicked but it rolls back down the track. The right guide is way too close to the track. The ball is striking the right guide and there's not enough momentum left to shoot out. Move the right guide towards the right.

• Ball is shot out and hitting the right slingshot most of the time. Ball is riding up out of the groove onto the right track. Even when the guides are aimed like a funnel towards the center groove, the ball bounces off the right guide and hits the left guide and by that time, it's moving towards the right. Open the guides back up.

It seems to be working a lot better and the present ball guide positions are shown in the photo below.

Gottlieb Subway Kicker-3 (resized).png

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