# Episode 132 - Score Motors - Exhibit **Source:** For Amusement Only EM and Bingo Pinball Podcast **Type:** podcast_episode **Published:** 2015-07-21 **Duration:** 13m 52s **Beat:** Pinball **URL:** https://foramusementonly.libsyn.com/episode-132-score-motors-exhibit --- ## Analysis Nick Baldridge provides technical guidance on soldering switch adjustments in electromechanical pinball machines and delivers an in-depth explanation of score motor mechanics in 1930s-1940s EM games, particularly the Exhibit Supply Company's 1947 Mystery machine. He discusses how score motors use rotating cams to handle complex multi-step scoring scenarios, addresses maintenance challenges related to Vaseline-based lubrication hardening over 70+ years, and recommends proper oil-based lubrication practices. ### Key Claims - [MEDIUM] Score motors were likely introduced to coincide with the rise of multiple types of simultaneous scoring in games around the 1930s — _Nick Baldridge speculating on score motor introduction timeline based on game design evolution_ - [HIGH] The Exhibit Supply Company's 1947 Mystery machine uses a score motor with three different cams to handle 1,000, 5,000, 10,000, 100,000, and million-point scoring — _Nick Baldridge describing his own 1947 Exhibit Mystery machine in detail_ - [HIGH] Exhibit Supply Company recommended Vaseline as a lubricant for score motors due to post-WWII oil shortages — _Nick Baldridge explaining historical manufacturing constraints and lubrication practices_ - [HIGH] Vaseline hardens into a cement-like substance after 70 years of air exposure, requiring complete removal and re-lubrication with proper oil — _Nick Baldridge discussing maintenance challenges with original Vaseline-lubricated motors_ - [MEDIUM] Similar stacked cam motor designs were used by Gottlieb and United for many years — _Nick Baldridge mentioning future episode on Gottlieb and United score motor designs_ - [HIGH] Soldering should only be applied to the backside of switches, not the contact face side — _Nick Baldridge providing technical correction/clarification at episode start_ - [HIGH] Soldering switches should only be done on low-intensity switches, not high-powered switches like flipper switches or end-of-stroke switches — _Nick Baldridge providing technical safety guidance_ ### Notable Quotes > "The score motor is essentially, when you boil it down to its essence, a rotating mechanism that will allow for multiple scores in a single point type." > — **Nick Baldridge**, ~5:30 > _Core definition of score motor function in EM machines_ > "Now, Vaseline is petroleum-based, and so, similar to oil, it will lubricate to some extent. But the problem with Vaseline, as you may know or have surmised, is that over time it will harden into cement." > — **Nick Baldridge**, ~13:00 > _Explains historical lubricant problem and degradation mechanism_ > "So what they suggested because again oil was not something that was readily available was to lubricate the score motor with Vaseline." > — **Nick Baldridge**, ~12:30 > _Provides historical context for post-WWII manufacturing constraints_ > "You should only do this on switches which are relatively low intensity like that score motor actuator switch that I was talking about." > — **Nick Baldridge**, ~1:15 > _Safety/technical guidance on switch soldering limitations_ > "Most of the relays needed slight adjustment, and then the game played perfectly until I had to switch give out just recently." > — **Nick Baldridge**, ~9:30 > _Personal anecdote about ongoing maintenance challenges with 1947 Mystery machine_ ### Entities | Name | Type | Context | |------|------|---------| | Nick Baldridge | person | Host of For Amusement Only EM and Bingo Pinball Podcast; EM pinball enthusiast and collector with technical expertise in machine repair and maintenance | | Exhibit Supply Company | company | 1940s pinball manufacturer responsible for the Mystery machine discussed; described as one of the major manufacturers from the 1940s post-WWII era | | Exhibit Mystery | game | 1947 electromechanical pinball machine manufactured by Exhibit Supply Company; subject of detailed technical discussion regarding score motor mechanics and maintenance | | Gottlieb | company | Major EM pinball manufacturer that used similar stacked cam motor designs for many years | | United | company | EM pinball manufacturer that used similar stacked cam motor designs; mentioned as subject for future episode | | For Amusement Only | organization | Podcast focused on electromechanical and bingo pinball machines; hosted by Nick Baldridge | ### Topics - **Primary:** Score motor mechanics and design, Electromechanical pinball machine maintenance, Switch adjustment and soldering techniques, Lubrication practices for vintage pinball machines - **Secondary:** Post-WWII manufacturing constraints and material substitutions, 1940s pinball manufacturers and design practices ### Sentiment **Neutral** (0) — Educational and technical in tone; Nick provides straightforward technical information without emotional valence. Shows mild frustration about lawn maintenance delaying machine repairs but maintains professional podcast demeanor. ### Signals - **[restoration_signal]** Detailed guidance on proper lubrication of EM score motors, including removal of hardened Vaseline and application of appropriate motor oils (confidence: high) — Extended discussion of Vaseline degradation over 70 years and proper oil-based maintenance procedures - **[restoration_signal]** Technical correction on proper soldering technique for EM switch adjustment, with safety caveats about not applying to high-powered switches (confidence: high) — Opening segment provides specific guidance: solder only backside of switches, avoid flipper and end-of-stroke switches - **[historical_signal]** Post-WWII material shortages (oil, copper) forced pinball manufacturers to use alternative lubricants like Vaseline, creating long-term maintenance issues (confidence: high) — Nick discusses oil shortage after World War II and Exhibit Supply Company's decision to use Vaseline - **[design_innovation]** Score motors introduced to handle multiple simultaneous scoring types in 1930s-1940s games; specific cam-based mechanism for tallying multiple units of same score (confidence: high) — Detailed explanation of how 1947 Mystery uses rotating cams with multiple teeth to pulse steppers exact number of times needed - **[operational_signal]** Recommendation to check and lubricate score motors during any machine teardown or service, with emphasis on researching proper oil weight by manufacturer and motor type (confidence: high) — Nick advises checking score motor movement whenever tearing down a machine and researching proper oil weight before lubrication - **[historical_signal]** Exhibit Supply Company identified as one of the major pinball manufacturers of the 1940s, distinct from the 'big three' manufacturers of the 1950s-1970s (confidence: high) — Nick notes Exhibit is 'not one of the big three EM manufacturers of the 60s, 70s, and 50s this is one of the big manufacturers from the 40s' --- ## Transcript what's that sound it's for amusement only the em and bingo pinball podcast welcome back to for amusement only this is Nicholas Baldridge so a couple quick addendums to last night's podcast i should mention that you should only apply the solder to the backside of the switch, meaning not the side with the flat contact face but the opposite side. This is the point at which the switch pokes through the leaf and is normally compressed into place. Another thing that you can do, this is the second thing, is that you do not want to do this on a high powered switch such as a flipper switch or an end of stroke switch. You should only do this on switches which are relatively low intensity like that score motor actuator switch that I was talking about. Okay, so moving on to tonight's topic, I wanted to start talking about score motors. I'm not sure exactly when the score motor was introduced, but I do know that many games in the 1930s did not have a score motor, and I would imagine that it started to coincide with the rise in multiple types of simultaneous scoring. For example, on my 1937 game, you have two different types of lighted scoring. You have hundreds and you have thousands. There's only a single switch on the playfield, which will give you a step up on 1,000. Then you have a 100-stepper, which when it reaches 900, the next step will return that stepper back to zero, but increment the thousands. Now on a game that has 10,000, 100,000, and 1,000,000, you have multiple things going on. Beyond that, you may also have 1,000s. And so on the playfield, you may have items which score 5,000. And if you've ever wondered how the machine can keep track of that, here's the podcast for you. The score motor is essentially, when you boil it down to its essence, a rotating mechanism that will allow for multiple scores in a single point type. Anytime the machine has to think it going to go to the score motor Now most EM logic can be handled without turning the score motor There are only certain instances when the score motor has to be actuated, and those usually involve multipliers on a single type of scoring. So let's take my 1947 exhibit, Mystery, the machine I talked about hacking up last night. That game has 1,000 scoring, 10,000 scoring, 100,000 scoring, and a million scoring. It's rare that you just get 1,000 points. In that game, there are many passive bumpers, most of which score 1,000 on the initial hit, But then there are mini bumpers which score 5,000 points. There are also three trap holes in the game, or kick-out holes rather. And these kick-out holes score a random amount, and then we'll kick the ball out. Now, the game has to think in order to score the random amount. The game also has to think in order to score 5,000 points. The game doesn't have to think in order to score 10,000 points or 100,000 points or even a million points. It only has to think when there are multiples of a particular score. So, taking the 5,000 as an example, the game has to actuate the thousandth stepper five times. It can't be more than five times. It can't be less than five times. It has to be exactly five times. So there have to be five pulses sent to the step-up coil on the thousandth stepper. Well, the way this works is the score motor contains several cams. When the motor turns, and this is a pretty efficient design, by the way, when the motor turns, there are, on the Mystery, three different cams. There's one with many teeth, there's one with fewer teeth, And then there's one that's basically just a big single tooth. So let's talk about the one with multiple teeth. That one, the teeth are spaced in such a way that they actuate a switch. And guess what that switch does? If you guessed that it stepped up the thousandth coil, you're correct. Now, it's only going to do that if other switches in the game are active at the same time. Otherwise, that switch does nothing. Then let take the next highest switch or cam That cam has two functions One is awarding the mystery score and the second is to reset the machine back to a zero state. Now, both of those functions only work when certain switches on the playfield are active or in the reset relay which is attached to the trip bank. Once the reset relay drops out and the score motor stops turning the game is reset. The third cam actuates a single switch. that switch pulses the kick-out coil which actually kicks out all three holes at the same time. If any one of those switches is misadjusted then the game won't score. Much more likely, however, is that one of the switches in one of the controlling relays in the backbox is misadjusted. When I first got the game, the switch for the kick-out hole was slightly misadjusted, and that caused the kick-out hole never to pulse. Most of the relays needed slight adjustment, and then the game played perfectly until I had to switch give out just recently. Still haven't fixed it I spent all night tonight mowing the lawn Hadn't done it for a few weeks because it's been raining every single day Here in Richmond for the past several months it feels like So the grass was about 7 feet tall I did get it finished but that didn't give me time to work on the games tonight So, tomorrow, hopefully, I will change that switch But there's no guarantee At any rate, the maintenance on this score motor And we're only talking about this one game from the 40s Which is made by Exhibit Supply Company So this is not one of the big three EM manufacturers Of the 60s, 70s, and 50s this is one of the big manufacturers from the 40s and during that time you have to remember this is right after World War II had ended and many things were in short supply oil was in short supply copper was in short supply all kinds of things which are needed for the manufacturing operation of a pinball machine were not really available. And so they had to do what they could to make these machines get them on the street get them earning money so they could sell more games So what they suggested because again oil was not something that was readily available was to lubricate the score motor with Vaseline. Now, Vaseline is petroleum-based, and so, similar to oil, it will lubricate to some extent. But the problem with Vaseline, as you may know or have surmised, is that over time it will harden into cement. Not really cement, but it does harden, and this happens when it's exposed to air over a period of, say, 70 years. So, the fix for this is to chip all that away and then lubricate with a small amount of oil. Now, there's also a lubrication point in this particular type of motor, and we're talking about a stacked cam on top of the actual motor. A similar design was used by Gottlieb for many, many years and United, and I'll be going into that in a future episode. But in this one, there's a single lubrication point and a wick, which will allow you to use oil. so if you want your motor to run smoothly and quietly for many years to come it is a good idea to lubricate every so often anytime that you tear your machine down to shop it it's a good idea to check your score motor's movement and apply lubrication if needed but the best thing to do is to clean off the prior lubrication before applying new lubrication and your motor is going to depending on the rpm and the manufacturer whether it's a sealed motor or an exposed motor it's going to require different weights of motor oil so it's best to research that before just pouring in any old oil that you happen to have lying around for lubricating discs or the like well that's all for tonight thank you again for joining me my name again is Nicholas Baldridge you can reach me at 4amusementonlypodcast at gmail.com or you can call us on the bingo line 724-BINGOS1 That's 724-246-4671. You can listen to us on iTunes, Stitcher, Pocket Casts, via RSS, on Facebook, on Twitter, at Bingo Podcast. You can follow me on Instagram at nbaldridge, or you can listen to us on our website, which is 4amusementonly.libsyn.com. Thanks very much for listening, and I'll talk to you next time. _(Acquisition: groq_whisper, Enrichment: v3)_ --- *Exported from Journalist Tool on 2026-04-13 | Item ID: d4c4510d-1c8b-4ffd-9885-da334c2a6ed6*