Quoted from hank35:
OK. After this fix, I went 50 for 50 on the auto plunge and had two perfect games with the auto fire working the way it was designed. I've tried every fix mentioned here and spent dozens of hours tweaking this.
Here's what (for now) finally worked.
Make sure your playfield is level.
Make sure both your auto fire prongs are touching the ball "at rest" and at the end of its cycle.
Clean and wax your playfield prior to adjustments.
MAKE ALL ADJUSTMENTS WITH YOUR LOCKDOWN BAR ON AND LATCHED.
Trust me on this one. Bar on and off produces different results.
1. I loosed the nut under the playfield that holds the top of the rail down.
2. I loosened the hex nut that adjusts the rail.
3. I inserted a plastic wedge to (slightly) move the rail more towards the playfield.
4. I adjusted the angle of the ball's trajectory with the wedge.
Pushing the wedge (down) towards the player moved the trajectory up towards the left mini flipper, while moving the wedge (up) away from the player moved the trajectory towards the rubber post.
5. After final adjustments, i'd say both screws on my machine are not loose, but they're also not snug. Tightening the nut under the playfield AND the hex screw at the end of the rail tight (like you'd expect) returned the game to erratic auto firing.
6. My final adjustments were with the wedge. I spent two hours yesterday and three hours today coming up with this "why does this work" fix.
If you're having problems, give it a try. Hopefully it'll work for you too.
Thanks for sharing all your experience with this issue. My shooter was working well until the 150th play or so and then started to misbehave "big time". Given all the MB's that depend on auto-launch working, this is a pretty major problem for this particular game layout.
Here's what I did that seems to improve the auto-launch behavior for me:
- The shooter guide screw closest to the gate has "play" to dial it in. After loosening the nut under the PF, I was able to move it away from the post ~1/8". I then tightened both screws.
- My left loop ball guide was loose. I tightened all 3 screws which had the effect of moving the guide 1/8" closer to the post in back of it (which gives the ball more room to roam).
- I dialed the Auto Plunger Power down from 255 (the max) => 245.
From my perspective, any approach that avoids tightening screws isn't optimal. Since my auto-launch worked nearly flawlessly for 150 games, it's clear that screws/nuts loosening up led to my game regressing in this regard.
I still have some issues with manual launch, however that's undoubtedly different and related to where the plunger is striking the ball (which seems off ever so slightly).
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