Electronic Tilt for Pinball Machines - Part 3

Just to keep you all updated on the progress, I’m ready to go full on with this project and allow sales of the electronic tilt. Message me if you are interested in acquiring one.

Beta testers have been using the prototypes for a number of months and I’m working on getting one installed in a retail location.

Latest blog post available at:


Can sensitivity be adjusted to different sensitivity levels, I mean from 1 - 10 for example? Usually TDs like a tighter tilt first and for the final round a more loose one.

Have you done anything to implement the design of the tilt bob into this? i.e. games are typically easier to nudge forward than left or right without a warning because of the Shepards crook effect. Does this simulate that?

I won’t deny that due to the shape of the tilt bob’s hook it makes a difference from which direction the force comes but I believe it to be tiny. I think nudging from the front results in less tilts bc the whole machine is more stable in this direction. Imagine we made a contest who can turn the whole machine for the most degrees with one powerful hit: Clearly a slap from the side (close to the flipper button) would move the machine more than a nudge from the front (close to the start button). Another factor is the position of the tilt bob or of the electronic measuring device. The closer the tilt device is to the nudge, the higher the measured force is (like measuring the strength of earthquakes). I believe though distance makes only a tiny difference but if the electronic device is small, it could be installed between the flippers, on the underside of the playfield.

Adjusting the sensitivity is the basis behind the design of the electronic tilt. However, instead of using a simple linear adjustment (ie 1-10 like a volume control), the electronic tilt uses real physics to calculate the sensitivity.

Just like a mechanical tilt bob, you adjust the mass up/down which affects the pendulous period. This is done as a software setting. Additionally, since the bob is triangular in shape, the electronic tilt has the ability to set the diameter of the bob within the ring which also affect the sensitivity. Got a larger/smaller ring? This can also be adjusted for in software. In other words it’s fully customizable so that you can mimic an existing setup or create a unique calibration to fit your taste. Part 1 of the blog covers this a bit

As part of my “To Do” list of future enhancements, I’m intending to have a drop down list of preset settings (i.e. Hard, Medium, Easy, Tournament, etc), but I haven’t had enough feedback yet from users as to what these presets should be

If you check out Part 2 of the blog at the end (Phase 11), I get into some details of the Shepard’s crook effect and what is being done to simulate friction in the X and Y axis. Each setting is independent of the other, so a nudge forward has a different effect than a side slap … again, fully customizable. Technically speaking, you could set the friction to maximum in one axis to completely ignore any bumping/slapping in that direction while minimizing the friction in the other axis so it will swing in perpetuity

The electronic tilt is designed to be mounted anywhere within the body of the pinball machine in any orientation. In most cases, people will install it where the mechanical tilt was installed.

The effect of a “Lever Arm” is inconsequential in most cases since the body of the machine is a rigid platform. Mounting on the left (standard tilt location) versus the right or even beside the coin box should yield similar enough results as to be unnoticable. Since the legs of the machine are the pivot points, you may see a slight difference between mounting the electronic tilt at the front of the machine versus the rear due to the length of the legs. However, I have not explored this in any detail since it is presumed that the bulk of the installs will be near the front of the cabinet for easy access.

Theoretically, mounting the electronic tilt a few centimeters higher/lower from the standard tilt location could change the angular movement in the lever arm … but again, this is rapidly becomes inconsequential when the pivot point (legs on floor) is a meter (~3.3 feet) away and the cabinet essentially moves fore/aft and left/right instead of rotating around the floor/legs

“Fully customizable” - ah great!
Before you work your ass off with a huge adjustment menu to mimic an existing setup we should ask if this makes sense. What was the intent of the mechanical tilt bob? It has been invented to prevent lifting, damage to the pinball machine & floor and to prevent annoying noise, while treating all players equally. More than 100 yrs the tilt bob has done a pretty good job. It’s not perfect though and now your electronic tilt is better in many ways.
Therefore it makes no sense to mimic the shortcomings of the mechanical device.
The shape of the Shepard’s crook never was a feature. It’s the way it is bc there was no better idea / other easy possibility.
From the player’s point of view nudging, quickly pushing sideways, single- or double slap-saving has the purpose of making the playfield slide under the ball while the ball continues its normal path (little friction aside). Therefore in a game-technical sense, measuring the force applied to the playfield is the prime objective.

I doubt that even the best players could figure out on which exact setting the tilt is when you offer 10 different sensitivities. Still, when factory tilt setting is 5, players will be able to feel how far they can go. A tournament setting is good. As I said, a general tournament setting and a final round setting with a bit more loose tilt would be perfect - maybe 3 or 4 and 6 or 7.

Probably you have to think of a way to prevent a slow lifting of the machine as then no strong force is applied.

Ideally you’ll find a way to integrate tilt settings in the general adjustment menu.

“…the bulk of the installs will be near the front of the cabinet for easy access.”
I admire your expertise, passion and the work you have and still will put in this project. Now don’t let yourself get carried away with unnecessary simulations and thoughts that anybody wants to see or touch your device. The best feature of the mechanical tilt bob is that it needs (almost) no maintenance. Copy that and your success will be inevitable.

Thanks for the input … Oddly enough, the input I get from others is foundation of new ideas to be implemented in the future. For example … a simple angle can be derived from the Z axis acceleration to see if the machine was lifted. Similarly, it can also detect a drop. Items I have already or will implement

The whole idea of mimicking a mechanical tilt bob is so that the electronic version can be a drop in replacement. Additionally, settings can be standardized around the world, so a person in London has the same tilt as someone in Sydney. It just so happens that the electronic version also offers options that are unavailable in the mechanical version. i.e. tilt warnings for older EM machines.

Just like an actual machine, there are numerous settings … and just like the machine, there will be settings that you will never change and others that you will. I’d rather over engineer the available options with many left at default than to minimize the amount and have people asking “Why can’t I change this?”


“…a simple angle can be derived from the Z axis acceleration to see if the machine was lifted.”
That’s what I thought. But has to be ultra-sensitive bc people will try this trick in slow motion.
I started playing pinball seriously when Gottlieb’s Surf Champ (EM) was still on location. When we tilted this machine with the ball still on the playfield we quickly lifted this heavy machine 2 cm off the ground and let it go. With quite some noise it hit the floor. The GI was flickering and we had a 2/3 chance of having the ball untilted. When the flickering ended with the GI being off the ball was tilted and we had to repeat the procedure. When we got caught by the owner spying through the backdoor in this side room, it meant 2 weeks house ban.
Not proud of it. Just saying: If something can be cheated, it will be cheated.

Easy replacement, standardized settings, 2 tilt warnings and no pendulum calm down time - that’s all great. What is not great is when someone mimics the long time swinging pendulum bc he thinks it’d be so vintage, adjusts to no or only 1 tilt warning, brings his machine to a tournament, forgets to adjust these settings and the ultimate MCA happens. In the future people might not trust for example the auto-calm down and we again see them taking a full minute until they finally start playing even if the tournament dictated electronic tilts for all machines - very boring. Don’t tell me this won’t happen. Alone at Pinburgh we see time after time tournament machines with ridiculous tight tilts. What can be screwed up, will be screwed up. And the blame might be on you. Therefore I’d make the device as idiotproof as possible.

Pls don’t get me wrong. I don’t want to dictate anything. I just think that bc you know all of the technical possibilities and are fascinated by your product, you somehow want to create something amazing out of it even though it doesn’t make sense for 99% of the people. I could’ve been you when I was younger but I believe now that I see your project from a beneficial distance and am not distracted by feelings. What should it be good for if someone can simulate a tilt bob with a Saturn-style ring and a friction of Venus’ gas atmosphere?

Important is that you think about mass-production. As you can’t copyright it, you’ll have to offer your electronic tilt to Stern and probably some more pinball producers just slightly over cost + shipping bc otherwise they will copy your idea and make it on their own. Only so they might let you have the niche market of owners of current and older pinball machines with standard tilt bobs. And while you earn a few bucks with these customers, you could be annoyed by stupid emails asking you why parameter 27b seems to be not working properly. Alone from this perspective I’d keep things simple.

In the near future I’ll visit the US for a pinball tournament tour. As it’s a lot of work to find out where the most and the best tournaments take place, I wish I had an app assisting me. Ideally I’d click check boxes that I like 5$+ entry fees, 100% payout (may include IFPA fees) and only tournaments where higher ranked players aren’t charged higher entry fees. Then the app would suggest me a few possible routes while keeping pretty much the base direction I entered at the beginning.

But all there is is the Pinball Map app which tells me where I can drop my coins. I won’t deny that it’s great to see where pinball locations are and how many machines they have. BUT Infos on lame flippers are completely uninteresting to me as ahead of tournaments machines usually get checked. Ok, Pinball Map also provides infos on tournaments but for my purpose it’s not much better than what I find on Google.
Why can’t I have it my way? Bc unfortunately here I’m in the 1% while the 99% are fine with Pinball Map…

“…But has to be ultra-sensitive bc people will try this trick in slow motion…”
slow motion or fast motion makes no difference, as the Z axis is sensed independently of the X and Y. It’s easier to sense a machine being dropped with an accelerometer than without. The same goes for lifting. The mechanical tilt bob only can sense X & Y axis and when the machine is lifted, the Z axis is transposed into the Y. It can not tell the difference between a lift and a bump. An accelerometer, on the other hand, gives us the ability to distinguish if the acceleration in the Y axis was caused by a bump or lift since we can compare 2 frames of reference.

The tilt bob swing is immediately zeroed after a tilt is achieved … zero wait time for the next player. In the case of a tilt warning, the tilt bob simulation will settle normally. Should you wish to zero the tilt between players then it can be done wirelessly with your phone or via other methods

That last bit would be great for shortening game times during tournaments. Imagine if a player could make a move that elicits a danger or two, then trap up to demonstrate control and ask a nearby td or “tilt attendant” to instantly zero out their virtual tilt bob so they can resume play. No more phone timers on games and 60 second countdowns after every hard move.

Would be even more fun if spectators or stream watchers could watch a rendering of the virtual bob as the player is playing (obviously kept out of sight of the player themselves). Virtual tiltcam. Might have issues with the crowd inadvertantly alerting the player how close they came to tilting though…

I’d think this would be more pronounced than you think… if the e-tilt is mounted in the far rear of the cab and someone smacks the front of the machine a quarter-inch to the left, there won’t be much leftward movement where the e-tilt is placed.

Excellent point about the mounting

I was only thinking fore/aft where the entire body will move in unison. The left/right will pivot/rotate to a lesser degree when mounted in the rear

The “live stream” can be viewed via wifi. It’s a web page interface updated in real time. I did a crude display in javascript, but anyone could make their own.

Can’t be cheated by lifting slowly then - great.

Ofc the electronic tilt shall never (simulate to) swing or after-swing at all. It simply shall trigger the 1st tilt warning when a nudge exceeds the predefined acceleration of x nm (Newton Meter). On the next nudge which exceeds x nm it shall give the 2nd tilt warning and a 3rd time means tilt. Again, to make this once and for all clear: A series of nudges with the strength of 0.99 x nm shall trigger neither a tilt warning nor a tilt.

The knowledge of better soft-nudging after a strong nudge due to the after-swinging of a mechanical tilt bob is not really an art. The little advantage an experienced player can squeeze out of it compared to an unaware player is more than equalized when difficult game situations occur in a short amount of time and he needs to continuously nudge hard and power slap-save and then he gets punished for no reason by a tilt. Therefore an electronic tilt shall not mimic swinging at all.

Or just set the damping to something reasonable, so the (virtual) tilt bob settles in 10-20 seconds.

“…if the e-tilt is mounted in the far rear of the cab…”
That’s why I suggested to mount it on the underside, between the flippers. This is the closest to where the playfield is attached to the cabinet, close to where nudges come from and symmetrical.

“Virtual tiltcam. Might have issues with the crowd inadvertantly alerting the player how close they came to tilting though…”
Not sure if even a tiltometer displayed on the pinball machine screen would be of great help to the player. Could be. Should be tested. Anyway this is future music and not important.

“Imagine if a player could make a move that elicits a danger or two, then trap up to demonstrate control and ask a nearby td or “tilt attendant” to instantly zero out their virtual tilt bob so they can resume play. No more phone timers on games and 60 second countdowns after every hard move.”
You don’t understand how it works. An electronic tilt doesn’t swing or after-swing at all unless it’s programmed to mimic such behavior.

QUOTE “Ofc the electronic tilt shall never (simulate to) swing or after-swing at all. It simply shall trigger the 1st tilt warning when a nudge exceeds the predefined acceleration of x nm (Newton Meter).”

I’ve programmed two types of tilt methods into the device. The first one mimics that of a mechanical tilt bob (Classic) and the second uses a basic Newton Meter (Simple). It’s up to the owner which one they choose to implement … Classic vs Simple … again, fully it’s customizable based on the wants and needs of the individual. You can leave the individual settings at default or change them at will. I’m not going to force one method/configuration on everyone. That being said, you appear to have a preference for the Simple method which is easily accommodated for. Personally, I prefer Classic … That’s the basic concept of “fully customizable”

@JShop Well stated. The damping/friction variable can be changed to achieve this … and to delve a little deeper, this can be set individually on the X and Y axis to mimic the Sheppard’s hook effect that was mentioned earlier.

Bc 10 - 12 sec is better than zero sec?

You prefer classic bc you like staring at the ceiling until the tilt has settled or do you play right away bc you don’t care when your ball gets tilt? Do you also like when by appropriate nudging suddenly a tilt occurs bc it happened by coincidence that the pendulum or simulated pendulum was accelerated a few times in a certain direction?

Note that these questions aren’t offensive but indeed very valid.

Let me start off by saying that I don’t like instant replay to make calls in sports because the referee making mistakes is part of the game. Similarly, the players making mistakes is also part of the game.

When it comes to tilting, it’s just part of the game. I don’t wait 60 seconds unless the previous player did a rage tilt, otherwise I’ll play immediately. The time it takes to switch players is generally sufficient enough for the tilt mechanism to settle

I LOVE the fact that repeatedly bumping the table has the ability to have a cumulative effect on the tilt … this is what makes it great in my opinion. The “Simple” method eliminates the cumulative effect of bumping and caters more towards the novice pinball player