(Topic ID: 104700)

Strange Science - Upper flipper coil?

By movingpictures

4 years ago

Topic Stats

  • 9 posts
  • 5 Pinsiders participating
  • Latest reply 2 years ago by Thrillhouse
  • Topic is favorited by 1 Pinsider


Linked Games

#1 4 years ago

I am currently restoring a Bally 1986 Strange Science.

My main issue right now is the upper flipper not having enough power to make the Atom Smasher (Ball lock shot).

The coil in there currently is the factory spec:

A-24-570 / 34-3600
(Bally/Midway part no AC70-0026-0000)

I would like to replace this with the strongest compatible coil.
Can any Strange Science or coil experts please chime in?
I'm not sure how to find the strongest compatible coil.

Thanks !

#2 4 years ago

I'm no coil "expert" but I can tell you the factory coil is more than strong enough to punch the ball up that Atom Smasher ramp loader. The trick with these is a total rebuild. Bally Linear flippers are notorious for getting terribly sloppy when they wear out. Always replace the sleeve AND the nyliner that supports the end of the plunger in the frame. The next biggest wear is the plunger and flipper pawl. The nylon roller on the pawl gets flattened causing a lot of play and the notch in the plunger can mushroom causing more slop. Lastly, get the tungsten contacts on the EOS switches filed nice and clean so that both sides make good solid contact. This is where the coil gets its juice and this switch set is daisy chained from the lower right flipper switches so clean and file those too.

I converted mine to the old style plungers and fiber links with old style pawls and while it makes them snappier (due to being lighter and less drag) it didn't seem to make them any stronger. Even with the original flipper mechs I'm able to load the Atom Smasher with all 5 balls, one right after the other.

Best of luck!

#3 4 years ago

Thanks Cliffy.
I cleaned the sleeve, coil stop bracket and plunger.
Didn't notice any mushrooming.
I will try a new coil sleeve and see if that helps.

Perhaps it is a worn out nyliner.
These Bally Linear's are tripping me up, I've never worked on a 6803 before and they are definitely not what I am used to.

I lightly filed the EOS switch contacts and they seem to be making good contact.
I tried to gap the EOS so it activates at the last possible second, but I am still having power issues.

Even with the glass off and perfect feed to the upper flipper, it simply does not have the power to make the turn-around 90 degree flip to load in the smasher.

#4 4 years ago

Make sure you don't have the incline too steep too and absolutely get 'er level side to side. Check the flipper bushing that the bat goes through. If it's cracked (VERY common) the energy will get lost in the bushing. WAAAAY back when I first restored my SS I had to have Steve Young machine new flipper bushings for me as they were NLA 20 years ago. They may be more available now but if not Steve can make them for you.

#5 4 years ago

There's no such thing as too steep. Someone told me that once. I forget who it was.

#6 4 years ago


The shot is finally make-able (yet very difficult) after the following tweaks:

- New nyliner
- New coil sleeve
- Much lower slope
- Adjusted EOS to last possible millisecond
- Waxing
- Superband on upper flipper

Thanks for the advice Cliffy!

And steve, now that the slope is very flat and the game plays slower, maybe you have a chance of putting up a good score? I know your reflexes aren't what they used to be

2 years later
#7 2 years ago

Ok, Digging up an old thread.
My question is related, but with all the coils.
My flippers all move free, and very clean, new sleeves, good pawls and i'm getting 46 volts at the coils. However, the power just doesn't seem enough.
I filed the eos switches and cabinet switches... Do I just need new ones?
I lowered the playfiled angle to about 4 degrees, but even that is a struggle to get the ball up the ramps.
What is the correct angle anyway?

#8 2 years ago

Bump. Still looking for answers.

#9 2 years ago

I had the same issue with mine. Try reflowing the solder on all the coils. Have you replaced your flippers lately? Make sure you have the correct style and that the screws are tight.

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