EM Gottlieb: Ball Return not kicking ball out to shooter - one cause | EM Pinball Tech

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15

#1 9 years ago

OP

GTB

DirtFlipper

Inactive member

Twin Cities, MN

12y 43,900 6,190 38

Howdy,

From time to time we see posts about the ball not getting kicked out to the shooter lane reliably on a Gottlieb EM. Either it takes several attempts, or if it does make it, it does so slowly.

There can be several causes involved, but I thought I'd share some detail on one cause that may not be so obvious.

Here's a standard ball return kicker:
Ball return kicker
2014Nov07 005.JPG
2014Nov07 006.JPG

Looks pretty decent, yes? It's clean and shiny, the fork is straight and isn't burred/mushroomed, and the plunger and linkage are tight. It even has a new spring on it (and the correct one).

But with this kicker, the ball would not make it to the shooter reliably (if at all). So some quick checks: the coil was correct (A-1496) and working great - new sleeve and all. Kicker isn't gunked up, and the spring is good. Score motor contact at 4C was clean and making good contact (as was the contact on the 'O' relay).

So why wouldn't this apparently good kicker get the job done?

Well, the way these things work is that when the coil activates, it pulls in the plunger with a rapid stroke, actually fast enough for the spring to stretch and store some energy. This 'shock absorbing' effect then takes that stored energy and moves the fork to launch the ball forward. The key here is that it launch the ball forward, and up into the ball trough ramp. If it's too weak, or shoots up, it either can't make it up the ramp, or (more likely), the ball is knocking on the underside of the apron and losing momentum.

A quick check is to lay your hand on the apron when the ball kicks out. If you can feel a thunk from the ball, it's hitting the apron. If you take the apron off, you'll see a skid mark from where the ball has been hitting it. (And actually, if you take the apron off, then the ball launch may actually start to work a bit.)

So what's going on then?

Taking the kicker apart further reveals the problem. At some point in this game's life, the original spring probably broke, and an incorrect substitute was used. And the kicker just got a whole lot of mileage on it (this particular game has at least 150K plays on it). Despite all that, it still sorta kinda worked, but not very well.

Worn out!
2014Nov07 009.JPG
2014Nov07 010.JPG

Running the kicker for that long under those conditions takes a toll on the post and the holes. Note how the post is worn down on two notches, and the post hole is enlarged.

When this happens, there's too much play between the sliding plates, and the energy is lost, such that the spring can't provide enough force. In this case, the ball was launching up into the apron underside, and then knocking back down onto the trough.

Unfortunately, there's not a whole lot to do about this but replace it with a good one. But in doing so, make sure the correct spring is used (the back of the '78 parts catalog will indicate which spring is correct for the games covered there). The wrong spring will result in the incorrect force too.

So the next time a game exhibits the weak ball return kick behavior, here's something else to check.

Good luck!

0

#2 9 years ago

MAO

MikeO

Pinside member

Overland Park, KS

11y 88,400 3,625 41

Nice write up, Dirt. Thanks for sharing.

0

#3 9 years ago

CJ

Chrisbee

Pinside member

11y 66,150 3,054 8

How are you going to fix that?

0

#4 9 years ago

OP

GTB

DirtFlipper

Inactive member

Twin Cities, MN

12y 43,900 6,190 38

Quoted from Chrisbee:
How are you going to fix that?

Replace it with a new one. One could attempt all sorts of voodoo with different springs, putting a sleeve over the post to take up the slack or such, but far easier to just replace.

0

#5 9 years ago

SDM

EMsInKC

Pinside member

Kansas City, MO

10y 79,550 4,024 22

PBR has these. That's the easiest fix.

0

#6 9 years ago

CJ

Chrisbee

Pinside member

11y 66,150 3,054 8

Quoted from EMsInKC:
PBR has these.

That's good to know.

0

#7 9 years ago

PMJ

PM_Jeremy

Pinside+ Frequent

10y 90,800 1,741 7

Excellent tip! I have run across this issue. Next time I will have to look closer.
--
Jeremy (central WI)

0

#8 8 years ago

MFS

goldenboy232

Pinside member

Alamo Heights, TX

9y 79,300 1,816 4 15

Dirt, the link on my Atlantis seems to be sloppy -- the little bakelite link at the top of the plunger can slide back and forth too much (I believe) on that post between the little "c" clip and the side of the mechanism. As far as I can tell, that's the only part that's worn out. The rest looks good to me. Should I just replace the plunger/link or the whole assembly to be safe?

0

#9 8 years ago

SDM

EMsInKC

Pinside member

Kansas City, MO

10y 79,550 4,024 22

Even when you replace it, you can still sometimes have issues. It was just not a really good design by Gottlieb. I've never had a Williams or Bally game have issues like this, but the Gottliebs seem to generally always have it.

0

#10 8 years ago

MFS

goldenboy232

Pinside member

Alamo Heights, TX

9y 79,300 1,816 4 15

Quoted from EMsInKC:
Even when you replace it, you can still sometimes have issues. It was just not a really good design by Gottlieb. I've never had a Williams or Bally game have issues like this, but the Gottliebs seem to generally always have it.

Interesting. Yeah my Top Card (similar era wedgehead) has no issues and that little bakelite link it nice and firm as it rotates on that post. So I'm either going to order only the link/plunger assembly from PBR, or a whole new unit.

0

#11 8 years ago

KJH

pinhead52

Pinside+ Frequent

Colleyville, TX

10y 91,050 5,223 13 2

Speaking of Bakelite.. whats wrong with this pic

Came out of a Buckaroo Im restoring, top 2 replaced by the bottom 2

20160204_172603_(resized).jpg

0

#12 8 years ago

BAM

monsonb

Inactive member

9y 46,900 414 8

Quoted from pinhead52:
top 2 replaced by the bottom 2

Where do you buy the bakelite sheets?

0

#13 8 years ago

MLF

stashyboy

Pinside member

High Falls, NY

11y 91,050 2,643 14 44

Quoted from monsonb:
Where do you buy the bakelite sheets?

PBR has both pre-cut/drilled links and uncut bakelite material that you can cut/drill to your specific needs.

0

#14 8 years ago

BAM

monsonb

Inactive member

9y 46,900 414 8

Quoted from stashyboy:
PBR has both pre-cut/drilled links and uncut bakelite material that you can cut/drill to your specific needs.

I should have checked there first. Thanks.

0

#15 8 years ago

MAO

MikeO

Pinside member

Overland Park, KS

11y 88,400 3,625 41

Quoted from pinhead52:
Speaking of Bakelite.. whats wrong with this pic
Came out of a Buckaroo Im restoring, top 2 replaced by the bottom 2

20160204_172603_(resized).jpg

The crank arms are not the same era between left and right. One is correct for that game and one is from a later model.

0

1

#16 8 years ago

REC

Cash_Riprock

Pinside member

Woodstock, NY

11y 51,050 1,782

To add to the list of what could happen, just ran across this kick-out problem on a pin(Ship Ahoy) I worked on for somebody.

Ball would take a few times and or slow to kick out. Upon inspection what had happened is, the separation in the chrome trim ring that is in the kick-out hole was lined up in line where the kicker arm rests....so what was happening was the kicker arm was sometimes getting 'stuck' in the separation(slot)in the chrome ring from the arm going back and not hitting the metal insert, and it was also wearing into the wood over time.

Just a heads up. I have never run into this before w/a kicker arm so maybe it will help somebody else.

0

#17 8 years ago

KJH

pinhead52

Pinside+ Frequent

Colleyville, TX

10y 91,050 5,223 13 2

Quoted from MikeO:
The crank arms are not the same era between left and right. One is correct for that game and one is from a later model.

A little drilling fixes it up

0

#18 7 years ago

???

KenLayton

In Memoriam

Olympia, WA

12y 83,400 5,965

Quoted from Chrisbee:
How are you going to fix that?

Could the worn post be drilled out and replaced with the appropriate size/length of a shoulder screw & locknut?

0

#19 7 years ago

JON

bronco-jon

Inactive member

8y 50,900 596 22

Okay, I was doing a search on ball return problems and found this. my Gottlieb King Kool, when credit button pushed the game resets all reels to zero but doesn't kick the ball out. I can hit the top of the right side rail (top of machine) with my fist and it will kick the ball out and plays fine until ball drains, then I have to hit machine again to get ball out to shooter lane. it does it every time ball drains. (just started doing this, was working fine). the points on the ball kicker are fine and making good contact. I can reach in the out hole and manually trigger the roll over switch and it will kick the ball out. any ideals?

0

1

#20 7 years ago

ZZZ

Wickerman2

Pinside member

9y 105K 6,825

Quoted from bronco-jon:
any ideals?

Maybe bonus unit...I think there's a switch that tells it it has completed checking for bonus or whatever. Clean that and make sure it's making good contact.

0

1

#21 7 years ago

JON

bronco-jon

Inactive member

8y 50,900 596 22

Quoted from Wickerman2:
Maybe bonus unit...I think there's a switch that tells it it has completed checking for bonus or whatever. Clean that and make sure it's making good contact.

Thanks Wickerman2! The problem WAS at the bonus unit.....I checked the switch points but not the contact disk lining up properly with the wipers.....sounds like you know ur stuff. Thanks Again! Jon

0

#22 6 years ago

???

Playdium

Pinside+ Frequent

Barnstable, MA

10y 82,550 2,164 6 2

When did Gottlieb introduce twin fork kickers? I have one as a replacement for a single fork kicker, however I'm not sure it's correct for the application. The mounting bracket is also reversed compared to the single fork mount. (Out hole kicker Gottlieb King of Diamonds)

0

#23 6 years ago

SYD

Eightball88

Pinside+ Frequent

Ottawa, ON

6y 60,550 628 6

Sorry to resurrect an old thread but...

My gtb Sky Jump has the double fork too, unlike the pictures in the OP (which is very useful btw). I’m wondering if this is original to this model or if it has been replaced. I’m having issues with the ball not kicking out...

0

#24 5 years ago

DJP

Sea_Wolf

Pinside member

Louisville, KY

5y 85,550 1,809 16 7

OP
Quoted from DirtFlipper:
Howdy,
From time to time we see posts about the ball not getting kicked out to the shooter lane reliably on a Gottlieb EM. Either it takes several attempts, or if it does make it, it does so slowly.
There can be several causes involved, but I thought I'd share some detail on one cause that may not be so obvious.
Here's a standard ball return kicker:
[quoted image]
[quoted image]
[quoted image]
Looks pretty decent, yes? It's clean and shiny, the fork is straight and isn't burred/mushroomed, and the plunger and linkage are tight. It even has a new spring on it (and the correct one).
But with this kicker, the ball would not make it to the shooter reliably (if at all). So some quick checks: the coil was correct (A-1496) and working great - new sleeve and all. Kicker isn't gunked up, and the spring is good. Score motor contact at 4C was clean and making good contact (as was the contact on the 'O' relay).
So why wouldn't this apparently good kicker get the job done?
Well, the way these things work is that when the coil activates, it pulls in the plunger with a rapid stroke, actually fast enough for the spring to stretch and store some energy. This 'shock absorbing' effect then takes that stored energy and moves the fork to launch the ball forward. The key here is that it launch the ball forward, and up into the ball trough ramp. If it's too weak, or shoots up, it either can't make it up the ramp, or (more likely), the ball is knocking on the underside of the apron and losing momentum.
A quick check is to lay your hand on the apron when the ball kicks out. If you can feel a thunk from the ball, it's hitting the apron. If you take the apron off, you'll see a skid mark from where the ball has been hitting it. (And actually, if you take the apron off, then the ball launch may actually start to work a bit.)
So what's going on then?
Taking the kicker apart further reveals the problem. At some point in this game's life, the original spring probably broke, and an incorrect substitute was used. And the kicker just got a whole lot of mileage on it (this particular game has at least 150K plays on it). Despite all that, it still sorta kinda worked, but not very well.
[quoted image]
[quoted image]
[quoted image]
Running the kicker for that long under those conditions takes a toll on the post and the holes. Note how the post is worn down on two notches, and the post hole is enlarged.
When this happens, there's too much play between the sliding plates, and the energy is lost, such that the spring can't provide enough force. In this case, the ball was launching up into the apron underside, and then knocking back down onto the trough.
Unfortunately, there's not a whole lot to do about this but replace it with a good one. But in doing so, make sure the correct spring is used (the back of the '78 parts catalog will indicate which spring is correct for the games covered there). The wrong spring will result in the incorrect force too.
So the next time a game exhibits the weak ball return kick behavior, here's something else to check.
Good luck!

Realizing ‘Dirt Flipper’ is no longer on Pinside, I was wondering if anyone else could expound on this thread. I recently picked up a nice Williams Space Mission for a good price and have resolved all the issues it had (thanks to a couple of fellas on here) except for the one brought up by the OP. Rookie here and haven’t been able to figure out the weak ball return. It’s not launching upward, it’s just weak. I cleaned the 4 A switch on the score motor as someone suggested and checked it but it didn’t help. After taking the apron off and manually tripping the switch underneath without a ball laying in the outhole, the coil fires and the kicker kicks forcefully but when you let a ball drain into the outhole, the kicker struggles to move with much force against the weight of the ball. It may take 5-7 times normally before it can get it up and over to the shooting lane and not forcefully at all like my Aladdin’s Castle. I took a smaller tilt ball and let it fall into the outhole and it can usually get it the shooter lane but still not with much force. Seems to me like it’s something mechanical but I’m too green to know for sure. I will be glad to post a video of it when I get home from work. Thanks for any advice.

0

#25 4 years ago

HRG

poppapin

Pinside member

12y 135K 11,332 6 7 1

Quoted from Sea_Wolf:
Realizing ‘Dirt Flipper’ is no longer on Pinside, I was wondering if anyone else could expound on this thread. I recently picked up a nice Williams Space Mission for a good price and have resolved all the issues it had (thanks to a couple of fellas on here) except for the one brought up by the OP. Rookie here and haven’t been able to figure out the weak ball return. It’s not launching upward, it’s just weak. I cleaned the 4 A switch on the score motor as someone suggested and checked it but it didn’t help. After taking the apron off and manually tripping the switch underneath without a ball laying in the outhole, the coil fires and the kicker kicks forcefully but when you let a ball drain into the outhole, the kicker struggles to move with much force against the weight of the ball. It may take 5-7 times normally before it can get it up and over to the shooting lane and not forcefully at all like my Aladdin’s Castle. I took a smaller tilt ball and let it fall into the outhole and it can usually get it the shooter lane but still not with much force. Seems to me like it’s something mechanical but I’m too green to know for sure. I will be glad to post a video of it when I get home from work. Thanks for any advice.

Was this ever resolved?

0

2

#26 35 days ago

CTE

essmeier

Pinside member

Tooele, UT

11y 30,650 182 12

My problem on my Atlantis appears to be due to part wear.

My spring was good, but the post hole on the plate to which the spring is attached is worn and is no longer round. That's preventing the mechanism from having smooth motion.

I've purchased a clean used replacement part. That should fix it.