Gottlieb King of Diamonds (Gottlieb, 1967) roto wheel

[Jonas 11]

Hi I have a King of diamonds pinball machine . The roto wheel I’m having a issue with . When hitting targets when roto moves every once in a while it will not line up properly with contacts so when target is hit it doesn’t score point. It will score when the ball goes through another rollover it will reset and work it happens periodically . I have loosen allen screws on the shaft and lined targets up . Then tighten them back up I still have issues any help ?

 

[pinballdaveh]

Hi I have a King of diamonds pinball machine . The roto wheel I’m having a issue with . When hitting targets when roto moves every once in a while it will not line up properly with contacts so when target is hit it doesn’t score point. It will score when the ball goes through another rollover it will reset and work it happens periodically . I have loosen allen screws on the shaft and lined targets up . Then tighten them back up I still have issues any help ?

I’ve never worked on the horizontal type of roto unit, but it looks similar to the vertical type.
With roto units it’s all about the return springs strength. The gear return action of the spring must be strong enough to return arm and plunger to the stop plate consistently and always align fingers on the rivet board. Cleaning and lite Teflon gel lube on the rivet board might help with friction.
If that’s not the problem and constant adjustment is often needed, the weld where the shaft meets the gear may be starting to crack, allowing slop in the unit. To check hold gear with one hand and hold the wiping disc with the other hand, and check for tightness.