Operation Moving IE!

This page is dedicated to our latest pinball toy project, making the Earthshaker institute move! This project has been talked about for years, but is now finally coming to completion in easy to add kit, for your non prototype machine!

Similar to our last project, making the Dr. Who Dalek head move for the Dr. Who pinball machine, our latest project adds life to a another playfield toy, that was omitted at the factory in production machines, most likely due to cost.

I don't know how many prototype machines were made, But the first "prototype" machines had an interesting feature where the Earthshaker Institute would sink into the playfield at certain spots in the game. Now you can have this feature back on your machine.

The following engineering pages, will document the history of this project, from beginning to end. A similar page was made for the doctor who project, and can still be found here


The first thing essential for a project like this is to obtain the proper pinball machine! I was lucky enough, to buy a production Earthshaker, and borrow a friend's prototype version that already had moving Earthshaker Institute.

Pair of shakers.jpg
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Upon pulling the moving prototype apart, I noted the construction consisting of one Opto board, two pillar is guiding the institute up-and-down, a roller / cam assembly and a 24 volt AC motor. the original motor spins at 12 RPMs

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Browsing through the catalogs to find a suitable motor was a more difficult than expected. We finally chose a 24 volt AC motor similar in shape in size to the original motor with the one exception that it turns at 8 RPM rather than 12.

The original tracks that supports the Institute, seems to have been made from either a cast resident or injection molded. Our reproduction will made out of black Delrin. The appropriate piece of Delrin was purchased and cut into the general shape of the original pillars. Similarly, aluminum was purchased to construct the mounting plate for the Delrin pillars, motor, and switches to feed back to the CPU.

First track cut into pillars.jpg
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First track cut into pillars 2.jpg
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Motor plate gets its first holes.jpg
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One of my main objectives with this project is to keep the cost down to a bare minimum. For this reason the pillars were constructed with the minimum of milling in our Bridgeport, as the simpler the part is made, the cheaper will be to reproduce. Once the tracks were cut in the pillars, and mounting holes put in the aluminum plate, the unit was assembled for the first time.

pillars - motor mounted on alum plate.jpg
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pillars - motor mounted on alum plate 2.jpg
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First fitting of the institute.jpg
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Although the initial fit looked good on the workbench, the thickness of the Delrin piece was too large to fit to the opening in the playfield. also, the chosen motor's driveshaft was longer than OEM motor used by Williams. new tracks had to be cut in two to Delrin pillar, and relief cuts had to be put into the pillars as well in order to make the Institute cleared the motor shaft and the entire unit it into the OEM playfield opening.

Once this was done and the unit physically fit into the playfield, the mounting brackets and plastic shield on top of the Institute were removed as they are in the prototype unit. Cam was cut out of acrylic,end to leave switches added to replace the opto board.

The Institute has its OEM mounting removed.jpg
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Must be removed.jpg
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Reproduction Prototype running down
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Reproduction Prototype running Up
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Major setback No. 1 is that the 8 RPM motor I purchased, does not have enough balls, to bring the Earthshaker Institute back the top the center.
The first thing you would think, when specifying the motor, is that if the original motor was 12 RPMs, and the replacement motor is to be 8 RPMs, that there is more gear reduction in an 8 RPM motor and the 8 RPM motor should have more torque.
Unfortunately this is not the case in my scenario. It seems that the way the motor manufacturer got the final output of 8 RPM, was too slow the actual RPMs of the main drive down, henceforth there is less reduction in my 8 RPM motor over the original 12.

Bottom line is I've ordered a new motor. The replace the motor is to be 12 RPMs, identical to the original but will run on DC rather than AC. the bad news is that the motor is five times more expensive than the motor on prototype No. 1. the other bomber is that now the AC needs to be rectified before it needs to the new motor, which also adds yet another part :-(


Well with some free time awaiting the new motor, I took the time to update drawings. Typically, projects start on cocktail napkins, make their way to graph paper then to cad.

drawing updates.jpg
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Switch bar now on CAD.gif
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Cool! The motor came in… The mounting is different, but that was to be expected. More holes were added to our prototype motor plate. Also, the overall shaft length is very different then the original motor, so the slot rails for the building to slide in need to be moved as well
The first prototype is named ALPHA one and is the unit I typically keep for may machine, Once all the parts fit and work on one unit, we build BETA one, which is the first unit built off of the final prints to insure they are 100% accurate … But I'm getting ahead of myself here

Replacement motor.jpg
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Modified plate for new motor.jpg
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New motor mounted with dual switch bar.jpg
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Ok, Next hurtle to Overcome! Its funny, trying to reverse engineer and interpret how the logic of the software in pinball machines are written. The Original unit uses 2 cams and 2 optos. Both opto are on when the building is full down and remain in that state till the building hits fully up where at that point one of the 2 optos is blocked. As the building sinks into the playfield, the second opto is blocked at the 10 o'clock position where the previously off opto turns back on at the 8 o'clock position. Both Optos are on again at fully down and the process repeats.
Trying to cheat fate I attempted to do single cam setup in hopes that the positioning was not as critical as I had hoped… BUZZZZZ….. Wrong answer!
Seems that 2 cams in unavoidable. This means that the originally chosen switches are too big and that they need to be moved. This means that the switch bar piece is wrong and needs to be remade and we need an additional cam, This also makes the spacing of the building wrong again as now there is more to fit behind the building so yet another slot needs to be milled for the building to move in. The Last picture shows that it all fits now with the exception that the switches are still too big and need to be moved.
My intent is to début this at the Pinball Wizards Convention in Allentown PA in less then 2 weeks so I'm running out of time….. An A hook up harness need to be constructed too!

First failed cam set up.jpg
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New cams mounted.jpg
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Success! After choosing smaller switches and remaking the mounting bar, this unit works! I made a harness for it too. The parts came in JUST in time to wire it up for the Pinball convention. The pictures below are close to what you get in the kit. Beta one will actually be more accurate to the end product as it wont have all the extra holes and slots as Alpha one. You can see some of the extra slots in this picture. The original unit uses a separate relay board, but our unit will be self-contained with the relay and rectifier to run the motor mounted on the switch bar. We have mounted it in on the playfield and it all fits. The only issue left is the motor speed. Although the original motor was 12 RPM and my motor is 12 RPM, my motor is running raster that the original prototype when you see them run side by side. The addition of a 100-ohm power resistor should slow it down to the correct speed… Off to Radio Shack

final modifications.jpg
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final modifications back side.jpg
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Cleaned up and mounted on the playfield.jpg
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Harness is plug and play - no soldering required.jpg
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Interface cable is made and plugged into the moving unit.jpg
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The speed issue was not too hard.. 100 ohm power resistor seems to do the trick! Check out the videos below. You will need the latest Real Player to see these. I tried making Mpegs of of them, but the image was to small and the file size was triple the .RM format Stills are on the Left, Videos on the Right. We also finished The Beta One unit, which, as stated before is the same unit without all the extra mistake holes and slots and is build of the CAD prints. This is also are back up unit if the Alpha prototype breaks at the Pinball convention. Next stop, Pinball wizards Convention for some Torture testing!

Side by side Earthshakers.jpg
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Side by side Earthshakers.RM
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Earthshaker close up one.jpg
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Earthshaker close up one.RM
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Earthshaker close up two.jpg
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Earthshaker close up two.RM
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Earthshaker bottom view.jpg
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Earthshaker bottom view.RM
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Earthshaker top view.jpg
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Earthshaker top view.RM
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Cams in action.RM
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Cutting to the chase, the Pinball torture test was a big success! This year I brought the William's prototype Earthshaker machine with the moving Earthshaker Institute and our replica of the moving toy, in my standard machine. Our reproduction handled the constant play very well as the rest of the machine shook itself apart. After day one I needed to resolder a handful or wires non the coin door, replace some ramp switches and repair the shaker motor. Looks like is time to start making production parts and make a manual!

Video and still of the reproduction moving toy below in Real Video format

Earthshaker @ PWC 2003.jpg
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Earthshaker @ PWC 2003.RM
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