This stuff is pretty spiffy, I have been using it in various places at the recommendation of many threads here.

Super Lube 21030 (resized).jpg

I think it is pretty well known that this is called a dielectric grease. What does dielectric mean, exactly?

Dielectric. physics. Dielectric, insulating material or a very poor conductor of electric current. When dielectrics are placed in an electric field, practically no current flows in them because, unlike metals, they have no loosely bound, or free, electrons that may drift through the material.

So basically, it does not conduct electricity very well.

I have used it in various places, shooter rods, spinners, etc. Whenever I do use it, I apply the absolute minimum I possibly can, just barely a bit more than nothing. This seems to make a nice lubricating layer that makes things smooth as silk.

Here is where I used it in a typical application I have seen. A super thin layer on these contacts on a 00-90 stepper disc. After I got it cleaned up and just slightly buffed I put it on the brass rivets so everything would glide smoothly.

00-90 unit back clean 4 (resized).jpg

Then I started thinking, wait a minute. I just added something that is basically insulating compound between 2 surfaces that need to conduct electricity. That seems to be the exact opposite of what I should do. Apparently everyone does it and everything seems to work well. What am I missing on the theory here? Or am I just overthinking things as usual?

Excellent, thanks! There is a lot of confusion and misinformation floating in that thread. The best piece by far is this article:

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

That's a nice analysis from someone more OCD than me. He concludes that he uses this (and similar dielectric greases) on electrical connections and it works great and causes no issues, in fact it is beneficial.

Specifically:

Permatex Grease

Nye Grease

super lube

All of these dielectric greases, and virtually all from other manufacturers, both improve insulation and preserve electrical connections. They do this by sealing contaminants, moisture, and air out of connections. They also seal insulators, keeping moisture and contaminants out of insulation. They are as effective at preserving connections as "conductive" grease, and will not harm insulation.

Well that answers that.

I'm in agreement with you on this idea. Especially for our pinball machines in home use. This condition is totally different than what they were originally used for. We have a pristine environment and low plays. Plus they tend to be treated well, and for that matter, carefully maintained. Just think, how many times do you get a machine that is 40-50 years old and is still in mostly original condition? It has never really been cleaned or gone through, maybe hacked a bit here and there to keep it running. Its filthy and gunky all over inside. And everything is still basically working as it should even after all those years, all those plays, all those moves from one place to the other. Maybe its a little slow here and there, and a score wheel is sluggish, or one function doesn't work as it should, but overall it all works. Now you religiously go through everything, disassemble and clean the stepper units, rebuild the pop bumpers, etc. Everything is tweaked and clean and snappy. How long with the dang thing last now in the home environment?? I mean that's got to be good for at least another 40 years. It will probably be humming along smooth as silk when we kick the bucket, even without any lubrication.

Also, the action of the things on a pinball machine are very robustly designed and executed. As an example, when you go in and use your finger on a solenoid plunger to test the action of a stepper unit, you might feel that it is a bit sluggish. Then you clean it all up, and when you move with your finger it feels "smooth and snappy". But that action is nothing at all like what happens when the machine actually runs. You don't come close to the speed at which it happens, when that thing gets the signal that solenoid jumps FAST and everything moves in an instant with a very positive action. I've been working on some of these ideas with stepper units including videos. That's going to be my next EM project I will post about, stay tuned!