Sticking slingshot FIXED

[BMHouze]

Checkpoint has a slingshot that occasionally stays out after deploying. I can hit the flipper button and it will return. I can wait it out and it will return.
I am not having any humming so I will assume the coil is not on.
I took off the coil cleaned up the coil stop and sleeve.
Wondering if it may be the spring on this feature as it is a original part.
I have also swapped out the transistor to this area.
When I originally got the machine this area didn't work. Worked after the transitor swap.
Wondering if I have got to the root cause of the inherited problem.
Thanks for the input,
Brad

 

[Menace]

When the sling gets stuck out, turn the machine off. If the sling goeas back to rest, the issue is electrical. If it stays out when you turn the game off it's a mechanical issue. Once you know which type of issue you are dealing with, then you can begin to form a logical plan of attack.

Update the thread once you have the above figured out and we can go from there.

D

 

[Seven]

Yup. Turn the machine off when it sticks and see if it returns.

Since it sometimes returns when you hit the flipper, I'm going to guess this is mechanical.

Try moving the assembly manually. Does it move freely? Does the spring pull it back? I've seen coils that previously overheated and melted the inner plastic sleeve just enough to create drag on the rod - or lock it up entirely. Sometimes it's as easy as replacing the plastic sleeve if it isn't stuck in the coil.

I had one where the coil sleeve was stuck and I didn't have a replacement coil. It was swollen right in the middle. Not much, but enough to not allow free movement of the rod. I found a drill bit the same size as the hole and carefully worked it by hand through the coil. I only needed to shave off about 1 MM - if that. I figured worst case I'd still have an unusable coil. Best case, it would work. It worked and I've been using it without issues ever since.

 

[Menace]

I've seen assemblies like this with grease on the pivot points from the factory that pack up pretty good. If that's the case just disassemble the whole sling mech, degrease it and reassemble. No real need for grease on this mech in a home use game.

D

 

[BMHouze]

I was a bit suspicious when the coil sleeve wouldn't come out.
I didn't have a large enough drill bit.

After looking through my pinball trash parts box I fould a flipper coil plunger assembly from the old bally atlantis that just fit the sleeve at the ends. I could feel the swelled spot in the middle of the coil and worked the piece through until it was moving freely once again.
I couldn't feel the tightness when it was installed at the start so I am guessing the slingshot coil arm is a bit smaller diameter than a flipper arm..
Now I just have to do some playtesting to be sure it is gone for good.
Thanks for the help.
I have one spare generic coil and can swap it in as long as I don"t end up needing it somewhere else in this machine.....
Now I just have to see if I can get the dmd to screw up again. But its another here today gone tomorrow issue.

 

[Menace]

I would be careful about using a flipper coil in place of the sling coil, unless they are the EXACT same part#. Usually sling coils are much higher resistance (read weaker) than flipper coils for a reason. If these are not the same it will work in a pinch, but you should really order the correct coil replacement for the sling.

D

 

[BMHouze]

I just used the old shaft from the flipper to strech the inside of the plastic coil sleeve. It was just sticking the off time.
Works great now.

 

[Menace]

Gotcha. Where the coil itself has swollen, the issue could come back at which point you will want to replace the coil to fix the issue permanently.

D

 

[BMHouze]

Yeah, I have a spare coil. Just needed to be sure that was the only issue going forward.
Planning on some downtime on this machine in the near future to address a few things.

 

[Seven]

Good to hear it was something simple.