First Time Disassembling & Reassembling a Stepper Unit

I've been fighting a cold and am resting as much as I can to get well but in the meantime I wanted to share the video Pinballorama made on cleaning stepper units. You get to see the stepper unit being disassembled and cleaned.

I'd forgotten about that after reading Clay's guide! Thanks for the reminder.

This is an important warning: NO steel wool for anything in an EM game, especially a stepper unit. The little steel wool "hairs" like to hang around and catch on fire.

Replay Stepper Unit reassembly:

The weather warmed up to where I was able to clean the frame with naphtha out in the shed that has better ventilation.

markg Thanks for the tip. I can see some uses for mineral spirits.

wayner I'm happy with how this stepper is coming after using naphtha and the ultrasonic cleaner.

The cog gear wheel is back in the frame with a little teflon lube and it spins easily. Tomorrow the other parts go back together and I'm using the photos in this thread as a guide.

Replay unit back together.

billc479 You're right about the shoulder bolts. It felt like I could easily strip the threads when I was threading the nuts, especially while tightening them. For the next stepper units on these games, I'll just leave them screwed in and clean around them unless they're really bad.

Naphtha and ultrasonic worked well for cleaning and I used a light coating of teflon lube where it's metal against metal.

Someone took the coil, coil stop and linkage from this game in the past. I used the replay unit on the other game as a guide for assembling the two arm linkages. I also have a new coil and coil stop from PBR ready to use with it.

The Replay Stepper Unit is done. Next is the Points Stepper Unit which is similar to the relay unit in that it increments and decrements.

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Pictures to help me remember how the Point unit goes back together. That coil sprang apart like a jack in the box lol. I ordered a replacement from PBR.

I left the shoulder bolts and switch stack alone this time. I plan to clean the shoulder bolts and other parts with naphtha then lube and reassemble.

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Two down. Three more to go. 10,000 Stepper Unit is next.

It's getting easier after doing the second stepper. I'm seeing how they're supposed to go together and caught one small spring I'd hooked up wrong on the Replay unit.

10,000 Unit done. Doing the Replay Score Unit now.

I'll post pictures after finishing the steppers. I only had to take a couple pictures of the 10,000 unit.

So far so good. The 100,000 Stepper Unit (last one) parts are being cleaned and lubed and it's a big one! Will post photo of it soon.

I'm taking a picture of the assembled unit first. Then a picture of the disassembled parts in in separate groups. This makes it easier for me to put it all back together.

This Ultrasonic cleaner is by far the best way to clean that I know of. It cleans deep where you can't reach.

Naphtha is great for cleaning the steppers and parts before lubing.

Five stepper units done. I'm getting the mechanical panel ready to put in the backbox.

Thanks to

zacaj
steveintexas
pinheadpierre
way2wyrd
briehl
billc479
spinal
phil-lee
markg
wayner
chas10e

for all your help and support with this endeavor. I put off doing this as soon as I found out the other game was available last spring so I can use the second game as a guide for disassembly/reassembly. I didn't have the confidence to do this otherwise.

I hope this helps others doing this for the first time.

Pictures of the rest of the steppers while I was working on them.

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Thank you. I'll post a picture of the board with all the steppers back on it after I replace the three burnt out coils with new ones from PBR.

Here is a photo of the cleaned and lubricated steppers as promised. I just need to solder the new knocker coil in and it looks like I'll need to replace two other burned coils.

It's actually easy to disassemble these steppers. The only scary part is forgetting where the springs, screws, etc go when you put them back together.

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