(Topic ID: 74772)

tech: repair found for AC/DC autofire plunger getting weaker and weaker

By playernumber4

10 years ago


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  • 88 posts
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  • Latest reply 1 year ago by j69
  • Topic is favorited by 35 Pinsiders

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There are 88 posts in this topic. You are on page 1 of 2.
#1 10 years ago

It started being weak occasionally about a month ago, and now is consistantly too weak to get the ball up to the top of the playfield.
I just wondered if anyone else had this problem and a suggestion before I start tearing things apart, ordering coils etc. Thanks!

#2 10 years ago

It has something to do with a bushing in the auto plunge assembly. I don't know if you can just re-secure it or if you have to replace it.

I have not personally looked into mine yet, but I have noticed the auto-plunge not consistently getting it up.

#3 10 years ago
Quoted from Allibaster:

I have not personally looked into mine yet, but I have noticed the auto-plunge not consistently getting it up.

Isn't that what Cialis is for?

#4 10 years ago

You need to pull the apron off and look at the actual mechanism. Either the coil has come loose and is now pinching the plunger, or the coil sleeve is worn and needs to be replaced.

edit: sorry, I don't have a manual nearby and now I'm thinking mech is under the playfield which will make it easier to inspect it's function.

#5 10 years ago
Quoted from gweempose:

Isn't that what Cialis is for?

It was probably fixed with the Luci edition.

#6 10 years ago

Mine has the same issue. I stared at it a bunch but that did not fix it.

Seriously though it's not something I could just look at and fix I see the shoehorn thing that makes contact with the ball but don't know how to adjust what is attached to it. Auto launch rarely makes it to pop bumpers let alone the jukebox hole. Paging LTG!

#7 10 years ago

There is a thread on this somewhere. I'll try to find it.

#9 10 years ago

Well, it gives me a few things to look for tomorrow thanks.

It kind of sounds like a common problem that nobody has managed to fix yet.

#10 10 years ago

Bump

#11 10 years ago
Quoted from starbase:

Mine has the same issue. I stared at it a bunch but that did not fix it.
Seriously though it's not something I could just look at and fix I see the shoehorn thing that makes contact with the ball but don't know how to adjust what is attached to it. Auto launch rarely makes it to pop bumpers let alone the jukebox hole. Paging LTG!

I'm thinking something came loose that takes the brunt of the kickback when the coil fires. I was going to get into it today, but now will have to wait a few days. There must be something loose in the anchoring of the coil or assembly.

#12 10 years ago

I started one awhile back also. http://pinside.com/pinball/forum/topic/acdc-pro-auto-launch-is-it-always-a-random-strength

Ultimately I am still having some issues with mine also, but haven't ever tried a new bushing and I haven't checked the tip contact with the forks in awhile. It is better than when I originally posted though.

#13 10 years ago

I had this issue on my acdc, the problem was that the "forks" on the autoplunger was to far apart so the ball wasnt resting evenly on them. It was fixed by bending them with a plier just a little.

#14 10 years ago

This an inconvenience on home-use machines. When you are trying to beat a high score(on site or in tournament) it becomes quite handy - just keep tapping the plunger to delay the balls from launching.
Another handy hint: use strips of bacon as skin grafts when your pig grazes itself.

#15 10 years ago

Yes, I would just prefer to be able to dis-able it. Of course I would like to be able to enter a custom message on it too but it does not look like Stern is going to give us any new code with those options in it.

#16 10 years ago

My SM has always bin like this, but not bad until several games have bin played. I bought a new coil and was going to replace it but never did. I just thought I'd throw my two cents worth in because in my case it seams to be fine for a few games until something gets over heated evidently because it gradually gets slower at that point. It gets weaker during a few multi balls. I've put up with it because it's the worst during multi balls, but with SM the ball doesn't have to go all the way up. A weak launch will just come down in the middle

#17 10 years ago

Yea.. multiball mode gets extra insane if they punch out and don't go up to the pop bumpers, but rather just dribble out the shooter lane and straight down toward the right flipper. Also I think if you could turn off autolaunch that for this game it would make multiball mode dang near impossible to play.

#18 10 years ago

I found a fix. There is so much slop in the factory mechanism that replacing the plastic bushings would do no good. The forks can fall into any position as a result of this slop. The easiest fix is to tighten up the tolerance before the shaft in the coil activates the fork to hit the ball. A simple spacer of any type accomplishes this. I used a soft half of velco, and it obviously will not hold up. The hard plastic half of it might. I will glue in a metal shim later. But for now I ran it through 12 games and everything worked perfect. Here is a picture. You can adjust how far you want the ball to go by using a different thickiness spacer. Good luck to all....

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#19 10 years ago

I'll have to take a look at mine and try that. I know I have a few squares of velcro (both types) lying around here. Seems like a thin hard rubber foot meant to put on the bottom of bowls or maybe cabinet doors might do the job and be more durable. Not sure how thin you can get that stuff. I'm wondering if maybe a piece of plexiglas the right thickness with some double sided tape (with no foam) might do the trick also. I'm pretty sure metal on metal would work, but seems like somehow using something softer for the fix might be safer for the "real" working parts of the game.

#20 10 years ago

Im a bit confused on the fix. I think you say the primary issues is wonkiness in the mech... So how does that tiny strip of velcro help eliminate the wonkiness. Is the wonkiness in the shaft that goes up and down in the coil, in the pivot (blue in your picture), or in the main rotation point (far top) of the pic. Sorry i am a newb and just trying to understand.

Thanks.

#21 10 years ago

I don't understand how this solves the problem either with all the play still in the pivot.

#22 10 years ago

I don't know either. Maybe it just takes some of the slack out of the mechanism. But however it does it....the fix works and the game is now back at 100%. When the velcro gets torn up I will have a more suitable material available. This was just a wild assed guess for the fix and it worked perfectly so I did not pursue it any further. I would like to know what the actual permanent fix would be if anyone ever finds out.

#23 10 years ago

As luck would have it, mine literally started doing this for the first time last night in the middle of a great game. It started launching balls during multiball, and most of them were barely making it out of the shooter lane. Gonna try some of the suggestions above to see if I can fix it.

#24 10 years ago

I haven't had time to try the Velcro or similar thickness style fix like this yet. Might later today.

#25 10 years ago

I've been looking online for the past hour and all the manufacturers for flanged oilite bushings seem to be in the UK! I will go to a well stocked machine parts supply place I know of in Detroit after the holidays and see what they have. I'm pretty sure those crummy plastic split sleeves need to be replaced with a sintered bronze bushing in standard dimensions.

#26 10 years ago

Ok.. I've now looked at my ACDC and at my Avatar machine. They both have the same autolauncher and have what appear to be equal slop IMO. Avatar however has worked 100% every ball for my ownership time of almost a year. I haven't checked, but that is probably close to 1200 plays. I did another generic search on here for "autolaunch" and found one talking about the fork linkage piece that they sell here: http://www.pinballlife.com/index.php?p=product&id=657
Based on the slop I DO see I don't hardly see how a brass/titanium/unobtanium bushing in place of the plastic ones would do anything at all. I also still don't understand how a velcro square could do anything either. The slop I see is more of a side to side slop which is MOSTLY in the linkage section where the blue piece shifts side to side on the pin that goes through it. I would sooner think that some sort of a soft foam in the shooter lane keeping the fork alignment would do the trick... that or maybe some other way to put a groove in the center pin in that linkage and keep it dead center. IMO if that linkage was all cinched together with a closer tolerance it would work a lot better.

I'm gonna take a look at the shooter tip contact with the autolaunch forks yet again and try a piece of velcro. What I THINK happens with the velcro is that by putting that extra buffer up there it alters how far the forks travel in some fashion that either helps straighten out the travel or something. Seems that the less it moves (and still has enough travel to make the jukebox shot) the better.

#27 10 years ago

Ok.. I just took a few and tried a couple of things. First take a look at all of these odd velcro and rubber bits I had lying around in my junk drawer in the 1st picture. In the second pic you can see I tried the "velcro location" fix and I also at the same time slapped one of the same pieces of rubber right along side that sloppy linkage bit... right next to the blue link. I can say that it did take a bit of the horizontal slop out of the linkage, but ultimately resulted in WORSE ball launches. Just by chance I was fiddling around looking at the shooter tip and wondered... what would happen if I pressed the shooter rod forward till the tip is actually touching the ball. EVERY launch with the shooter tip protruding out to touch or even protrude the ball forward some results in a jukebox plunge. Yep.. having the ball out 1/4" suspended by the tip and hitting the fire button results in a clean launch. In looking I see that every other few shooter lane kickouts the orientation of the autolaunch forks looks wonky. Most of the time the right side makes contact with the ball and not the left which would result in an uneven strike and spend the energy in an odd way. I'm figuring that by pressing the shooter rod forward the forks have to travel further forward and by the time they have traveled further than they normally need to go that by then they are more straight due to the linkage straightening as it maxes out its range. Sound logical folks? I am likely gonna try removing one or the other rubber pads and see if either as a single solution works.

Here's the question.. if just moving the shooter tip further forward fixes this how can you make that outer shooter rod spring shorter since I don't believe trying to compress it would be enough to make a difference without leaning on the plunger. I played a game and went through 2 multi balls and the balls all launched good with me leaning my hip forward into the plunger.

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#28 10 years ago

According to the people in the post I linked below, if the manual ball shooter tip touches the ball, it hurts not helps the auto-launcher.

http://pinside.com/pinball/forum/topic/tech-potc-autolaunch

#29 10 years ago

Ok guys.. I left the part between the blue plastic piece and the metal in and took off the upper portion where playnumber had used the velcro and it worked great for 2 solid games. I just basically let them drain and re-shoot... so I got a good 12 launches in a row straight to the jukebox where with leaving both rubber pieces it couldn't hardly even make it out of the shooter lane after 12 attempts. It appears that the side to side slop appears to be more the issue than anything in this particular case for me. I imagine a small zip tie or 2 depending on the size could equally do the same thing as this 1 sided sticky rubber solution. I'll keep an eye on it and see how long this keeps working better.

#30 10 years ago
Quoted from bub2010:

The slop I see is more of a side to side slop which is MOSTLY in the linkage section where the blue piece shifts side to side on the pin that goes through it.

If the fork pivot bushing is close tolerance, the linkage you refer to will have nothing to do with side to side slop in the fork. Getting the slop out of the fork allows you to tune the "tines" of the fork so that they each have proper and consistent contact with the ball thus allowing good auto-launches every time.

#31 10 years ago

After a few games the good launches faded. The rubber may have fallen off. I'll check tonight. Racer rick....why don't you make some up and come up with a price. Seems like enough interest here for folks to want them and best I know these work on all stern auto launchers.

#32 10 years ago

Regarding the .318 OD.....8 mm is .315. Thats probably close enough for this application. Maybe it would be easier to use a metric oilite flanged bushing and simply drill out the ID? I was hoping the roads will be clearer here monday and to allow me to get to a supplier to check on a standard part number possibility. But he weather report of 8-10 inches of snow just came in for sunday, so I won't be able to check further on the bushings until mid week.

#33 10 years ago
Quoted from bub2010:

Racer rick....why don't you make some up and come up with a price.

The reason I have not offered to build these is that I am not a machinist. I just dabble on the lathe and eventually build what I need. It took me four tries to get the bushing right...

#34 10 years ago

Been awhile since I read through some of the upper text and didn't remember if you did it or if someone did it for you. #4 lemme know what you find out on that bushing... yea.. you guys are getting buried and it if friggan C O L D up there. We are getting that storm Sunday it appears and while we may only get 4" of snow it is gonna be like -10 before windchill come Mon/Tues and that is freaking cold for Ohio.... probably near a record low if I had to guess.

#35 10 years ago

Well, the velcro spacer is still there and now the autolauncher is weak again. It got weak right when my white GI lights went our during gameplay. They are still on as normal during the attract mode. I must have one issue causing both problems. All the fuses check out perfectly with a meter and detached from the game.

Any suggestions would be appreciated.

#36 10 years ago

Mine is still launching better. I removed the rubber piece where you had your velcro and left the one that was helping take the slop out of the linkage and so far it is quite an improvement. Seems to make it to the jukebox most of the time, but not always. I can already tell that multiballs last longer due to the balls getting to the pops 90% of the time. Any word on the bushing player#4?

#37 10 years ago

Not yet...we just started unthawing today and my street got plowed. I should be able to get down that way tomorrow.

#38 10 years ago

Fully working or not I just got a personal high score. Hell's Bells was the starting song and for awhile it got friggan nuts!

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#39 10 years ago

OK, I had to work on the game tonight to determine why the white GI lighting went out....looks like the driver board. So while doing that I took apart the whole mechanism for the autolauncher and found two .050 thick washers in my misc. can in the garage. I put them on the shaft as shown in the pictures (one on each side) AND rotated the white plastic split bushings at the pivot shaft so that the split in them was at the side as the shaft pivots.

I reassembled and again the auto launch is working perfectly. I think the problem has been properly diagnosed earlier as those split plastic bushings being too sloppy. But being that I have to call pinballife tomorrow to order the driver board I am also going to order a pair of those split bushings (part #545-5423-00) in case I cannot find a standard oilite bushing to fit tomorrow. I checked the blue connector on the plunger and it is not cracked. At least with throwing in a couple of new factory plastic bushings I will be good to go for another couple of hundred games which will give me time to have my nephew machine up a special brass bushing sometime later as his schedule allows. I will post if I have any luck tomorrow.

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#40 10 years ago

Nice.. yea.. I need something on the other side of the blue linkage to make it 100% I believe. In having mine on just the side that connects to the metal linkage on the left I think that only solves about 1/2 of the slop. I'm gonna try to put a piece directlly on the blue part and see if that gets me up to 100%.

#41 10 years ago

Wanted to add something if I may.

Had very similar issues with my TRON Pro and although I did not try any new bushings, velcro etc... I DID notice that I had a very weak solder point on the Diode that controls the auto launch feature. (see image) RED arrow is actually pointing to the Diode that is in your machine, GREEN arrows show solder points.

So, when 1st firing the machine up, things would be normal for the most part, but over time, bad launches, flipper auto launch was taking like 4-5 pushes before launching ball, multi-balls would sit in shooter lane for several seconds before luanching etc... as some describe above with the AC\DC Pin, were happening to me as well on my TRON.

Once I discovered the bad solder point (which IMO got worse as the machine heated up, was played and bumped more) and touched up the Diode with a splash of solder onto the far right contact... Wa Bam! All is well now.

I borrowed one of your images playernumber4 (thank you) to illustrate where the Diode and solder points are. This is not an image of my actual (fixed) problem.

Yes, mine is STILL just as sloppy as all the others described above, but it is now making full launches, nothing sits in the shooter lane, and the flipper launch works as it should on 1st press of button.

Hope this may help some.Ball Launch Diode.JPGBall Launch Diode.JPG

#42 10 years ago

Hrm.. that is indeed an interesting situation. I've sometimes wondered if mine launches more wimpy as I play, but so far have not determined that to be the case. I think it depends on how good a ball I'm having and if multi ball is going on also. Obviously shorter ball play time and multiballs will make it have to do more work. I'll have to check that out on mine also.

#43 10 years ago

OK guys....after a half tank of gas an 6 hours of driving all around Detroit I found what I was looking for. It all came out perfectly except for one minor problem.....it did not fix the weak autolaunching problem. Looks like its time to call in someone who knows what they are looking for to see if there is a low voltage problem going to the coil. I don't know how to check that stuff. I do know that my LED driver board is shot but do not know if that would have anything to do with it. I cannot find any weak solder joints or other bad connections to explain this.
I'll post pics of the new sleeve tomorrow. I'm too bummed out about the whole day of work put into this for nothing at this point tonight to bother.

#44 10 years ago

Wel, here is the really nice looking and redesigned fulcrum pivot point with much less slopautolauncher 007.JPGautolauncher 007.JPGautolauncher 006.JPGautolauncher 006.JPGautolauncher 005.JPGautolauncher 005.JPGautolauncher 003.JPGautolauncher 003.JPGautolauncher 002.JPGautolauncher 002.JPGautolauncher 001.JPGautolauncher 001.JPG

I used an oilite bearing .250 ID, .375 OD and 1/2" long with a thin nylon washer with a slightly larger ID than the .375 of the bearing to keep consistant side space between the two brackets. Now the mechanism was consistently not launching hard enough but nowhere near as loose and full of slop as before. So some of the boys came over last night and had a few beers. Out came a pair of pliers and someone bent the left fork in more towards the center. Bingo! The game is now launching perfectly.

I used a .375 drill to open up the hole on the bracket and a dremel with a stone to clean it up and make it just barely big enough to get the bushing thru. The 1/2 length of the bushing is perfect with the nylon bushing being a slightly larger ID thanks to using a .375 drill in my hand to just scoop out a little bit of plastic to make it slightly larger so it loosely slips over the OD of the bushing.

If that arm bends again now I will flame harden it with the acetylene torch and a quench. I have 9 more bearings if anyone else feels ambitious.

#45 10 years ago

The bushing takes out the free play allowing you to adjust the arms of the fork so they contact ball properly. The fork is kind of soft so I expect it will need to be tweaked once in a while. You can't flame harden the fork because it is made of non-magnetic stainless steel which is not heat treatable.

#46 10 years ago

Ah....thank you very much for that information RacerRik! You just saved me from buying a new factory part!

Before changing to the bushing I was getting some success by spinning the splits in the factory plastic bushings around to the sides, but eventually they would move into the wrong position again and mess up. It sure is nice to have consistent ball launches again with a game that it really matters on.

#47 10 years ago

I played an AC/DC a couple weeks ago which had an autoplunger so bad it never once made it to the juke box. There were several pinheads talking about it and many people started complaining that their Stern games (not AC/DC) used the same mechanism and had the same problem. I don't understand why this has not been fixed after being a problem on so many games. Actually, I heard Star Trek uses a new design so maybe Stern has finally addressed the problem.

Happy to hear yours is working well cause it sure sucks the fun out of a game when it does not work right and you can't figure out how to make it better.

#48 10 years ago

Mine was so bad it would never make it to the jukebox...and it happened all within one day! They must have changed materials in the forked bracket or switched manufacturers. My SM, FG, Elvis and Xmen have never had a problem. I did not look under the playfields on how those mechanisms work though. Maybe the problem got worse from a change they made in that pivot point.
Think about it...if it goes sideways far enough the ball would just be pushing that tang sideways and bending it out. I think we saved some future problems be tightening up that pivot fulcrum area with our bushings.
I wish I knew how to change the title of this topic to "tech fix found" instead of "tech help please" now that we fixed it.

#49 10 years ago
Quoted from playernumber4:

I wish I knew how to change the title of this topic to "tech fix found" instead of "tech help please" now that we fixed it.

If you just edit the post and scroll up to the top you can do it...

#50 10 years ago
Quoted from bub2010:

If you just edit the post and scroll up to the top you can do it...

Done! Thank you very much bub. I've been trying to figure how to do that after seeing people changing their FS posts to SOLD posts. I'm more of a wrench and screwdriver guy than a geek to say the least but its always nice to learn something new.

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