Read this if you haven't already. The chart in the thread is directed towards Gottlieb, but I'm sure it was the same for all manufacturers.

https://pinside.com/pinball/forum/topic/modern-equivalents-of-gottliebs-white-lube-black-lube-and-fine-oil

teflon is somewhat new... when did teflon pans come out?
I use it extensively on my pins, have not had an issue.
It will not short, or block a signal.
used sparingly, it leaves a fine coat behind, which reduces friction.
And yes, it is a vast improvement to ...what was that stuff??? whale tallow?
what ever it was, it got hard as dry glue with age.
don't worry about it, just use it! great stuff.

Games used to come with little white tubes of contact disc grease, sometimes called "MBI Grease". It's no longer made, but Steve at Pinball Resource partnered with another company and produces a new product he calls "PBR Grease". I haven't tried it.

http://www.pbresource.com/tools.html

What's wrong with your stepper? Intermittent electrical connection between the wiper and rivets, or is the stepper actuation sluggish, intermittent, unreliable?

If it's a Gottlieb stepper sometimes you have to loosen up the allen screws on the shaft to give it some play or it won't work properly. Considering the design differences not sure how/if this would apply for other manufacturers.

Curious. Never done this, how would this help?

You should be able to actuate steppers easily with just light pressure on the lever from your fingertips. The only resistance you should feel is the return spring pulling the lever back. Once you stop applying pressure with your finger, the lever should snap back with zero hesitation. If it feels like there is any "dragging" in either direction, there is probably old grease that has solidified under areas where metal-on-metal pivots. You'll need to clean out this old grease and apply some teflon lube in its place. Applying light lubrication to these areas is not a hack, but stretching return springs certainly is. Steppers were precisely engineered so that return spring strength doesn't inhibit the work needing to be done by the electromechanical force of the solenoid coil. Once your stepper is clean, lubricated, and actuating freely, you might need to re-adjust the spring you shortened.

Here is a good thread on cleaning stepper units:
https://pinside.com/pinball/forum/topic/dirty-stepper-units

If you cleaned out the old gunk, it sounds like just a little lube is all you need at this point. I hope it makes the difference!

It's sometimes a vexing puzzle to find all of the many ways friction can sneak into stepper operation. The biggest stepper headache I had was the thermometer apparatus for Centigrade 37. It has to pull that ribbon up to the top and then fully retract when it resets. 5-6 little things needed tweaking to get it working just right.

Ok, I have an extra 2 cents, so...
if you have a sluggish/sticking step unit, remove the wiper from the shaft, and place it on a flat surface.
the wiper fingers shud all touch with little or no pressure applied.
sometimes, the short wipers get too much bend in them, and will bind.
if you see this on your step unit, bend the blades at the hub a little, till they all press down about the same.
you do not have to worry so much about the long wipers, they usually have enuf spring in them, to work without dragging.
but the short blades, catch on everything if they are too tight.
just a thot...

when new, yup, no lube needed...40 years later...well...

Teflon was first used on cookware in the mid-1950's.

Maybe a pic of the stepper would add more people's insight as well.

Is it a woodrail stepper?

If not re-setting can take hours adjusting brackets and position of coil bracket to get it 'just right'. Well, it takes me hours

Certainly think a little more info on what game it is in/at least era (pic or 2) is really going to help people get an idea of what is being dealt with.

Hence shapeshifters comment.

Fair enough. Was just trying to help with the specific one mentioned.

Myself, I do really like the super lube gel...sparingly of course. Found it at Ace hardware in automotive aisle strangely enough.

Double post. Sorry

I have used it and it's good stuff. However Superlube seems to work just as well. Either one....

It's always helpful to mention the game name and specify which stepper you are working on.

For all GTB small steppers made from the late 1940s through 1980, the torsion return spring on the stepper gear shaft should be wound exactly four times around and then attached to the frame spike.

As others have noted, the original unmodified drive spring should have more than enough power to index the stepper forward, and the torsion return spring should have plenty of power to return the stepper to the zero position, once the stepper is clean and lubricated and assembled correctly.

I also just want to mention that many times a spring will lose almost none of its "springiness" over time unless someone has manually stressed it beyond its normal operating range. The drive spring and torsion return spring used on the GTB small stepper are good examples. I've rebuilt many of these steppers on late 40s and early 50s games, and the original springs are nearly always in excellent operating condition.

I believe what Otaku was talking about in post #5 is the situation where the metal spider that holds the wiper disc has its inside edge riding very tightly against the frame bearing. This is a bad situation and will cause binding. There should always be about 1/32" of end-play in the gear shaft where it goes through the frame bearing so that this binding doesn't occur. If the spider is tight against the frame bearing, the fix is to loosen the spider set-screws, re-position the spider slightly farther back on the shaft to create a small gap between it and the frame bearing, and then re-tighten the spider set-screws. The spider must always be firmly attached to the gear shaft. The stepper will not work if the spider is loose on the shaft.

If you've done all this and the stepper is still binding, then it seems likely that a less-common problem is happening. For example, you might have ridges cut into the teeth of the stepper gear, and that is hanging things up. Pictures would probably help in figuring out what is wrong.

- TimMe

I have trouble understanding how if there is enough pressure between the spider blade contacts and the disc to make good electrical contact then lubricant actually does anything at all. It seems to me that either one or the other true, not both. ie: strong direct contact without interference or a thin layer of lube assisting movement.
Is there an explanation for for how this works ?

I don't believe the lubricant is used to help electrical contact. It is used to reduce friction so the spider slides over the contacts easier, reducing binding and sluggish movement. By using lubricant to reduce friction you can apply enough pressure to the spider to get dependable electrical contact with out binding.

Lubricant is there to keep parts from wearing out and to ease movement. If there is not enough spring pressure to insure the blades make good contact on the rivets, it is easy enough to replace the springs or what I do is remove them and stretch them a bit.

I have always used Super-lube.
No problems.

The very thin layer of lubricant is conductive. Almost everything conducts electricity at some level.

No.

No.
Think of Air- large gaps of Air are not conducive, but as you reduce the gap (or increase the voltage) the Air will conduct electricity. The Air acts similar to the lube.

But, it works.

At some level it does weaken the connection. But is so small that is doesnt effect the operation. I doubt you could measure it with a common Ohm meter(maybe- never tryed) The benefits of lube far outweigh the minute reduction of connection.

Everything conducts electricity at some level-
At some level everything has resistance-

I never use grease on steppers. Its not like these things turn at 6000 revs. It just collects dirt and causes problems. Cleaning is what frees them up. If there are switches on steppers I undo them because they get stiff with time and hold back the unit. After cleaning steppers with alcohol they should free up. Shoulder bolts usually need removed to be cleaned. Usually the only shafts I have to remove is to clean grease off. After stepper is free then adjust any switches that put pressure on unit. On large steppers sometimes I give them an extra turn on the spring if they wont reset.

If your getting stuck on this point and cannot live with the thought that you may slightly effect conductivity- without effecting function! Then use a conductive grease designed for contact points. It's completely unnecessary here and probably a semi bad idea as it will almost certainly gum up the works faster than suggestions your receiving. The fact is you can put almost any grease you can think of and it will not interfere with electrical function barring an incredibly thick coat. I routinely spray mine with a non conductive PTFE dry lubricant that leaves a nice slippery dry white coat of high tech "insulating" polymeric lube. Electrically my steppers all work perfectly and have for many years.

Conductive vs non conductive is not a real helpful way to think of these things when your dealing with what amounts to a molecular layer with high current and combine that with a dragging mechanism that rubs the contacts together. They are not especially useful terms here.

Just don't do something stupid like cover the whole thing in a conductive graphite or something! Only mentioning because I've seen it...

I still like thin layer of teflon gel, it has a high dielectric strength (so not going to short anything out) and offers a little protection from wear on those old bakelite pieces. There is a tight enough mechanical connection on a properly adjusted unit to allow wiper to displace most off the contact point so not really much electrical interface there, but helps it glide over entire stepper unit as it goes between contacts as well.

http://www.super-lube.com/multipurpose-grease-ezp-82.html

Superlube works wonderfully. The most important thing I can tell you is use sparingly. As in the lightest coat possible.

So I am somewhat curious at what speed a stepper contact runs at. So I decided to do a small experiment.
I used slow-mo on my phone and recorded a stepper reseting. With that I could time the speed of the wiper.
Here is what I found-
The stepper resets at 300rpm.
The wiper arm contact moves at-
3768 inches per minute-
314 feet per minute-
63 inches per second-
5 feet per second-
This seems fairly fast! Fast enough to need some lube.

Medium size write up about conductive vs dielectric grease...again, just someone elses opinion, but interesting...last line or two is a basic summary.

https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

Rufessor, the downvote was only in disagreence to ever using/suggesting a conductive grease. I like the explanation in the link about using it on a terminal if desired, but I don't personally like the idea of adding a potential for multiple contacts to short. In fairness to you, you did clarify and state you didn't think it was a great idea either.