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Final Project


Also you can see original files, slide and video.

What does it do?

I love pinball machines, But they are too big to put in my house. So I decided to make small and portable pinball machine by digital fabrication techniques.

My FAB-ALL PIN-BALL partially contains electronical mechanism and processing by microcontroller, input and output devices. You can play with this machine, launch styrofoam ball from 3D printed plunger, move flippers by pushing buttons, and if the ball passes certain points, photo reflectors detect it and pop bumper will bounce back the ball.

This project and files for making is shared under Creative Commons CC-BY 4.0 license as I think Assignment18. Invention, intellectual property and income.

More detail and first initial plan are written in my tracking page and project development.

Who’s done what beforehand?

I did an initial research in 1st week. DIY makers made their own homebrew pinball machines, and there is some commercial homemade pinball kits. Also some people tried to make in HTMAA/FabAcademy, but looks it couldn’t be completed.

PinBox 3000





Zaria Smalls’ Pinball

zaria's work

In my final project, I made wood-based small machine. It contains not-analog, digital input sensors, buttons, flippers and pop bumpers.

Components and Fabrication

This section contains answers for

  • What did you design?
  • What parts and systems were made?
  • What processes were used?


Considering the size and production efficiency, I designed and made the enclosure during the week of Assignment8, Computer-Controlled Machining by using Shopbot. I made 2 parts but I used only underside for final project. This is one of my subtractive Fabrication.




Play Field

Playfield, I mean the place ball will run around, are designed by mainly Adobe Illustrator, vector “2D Design”. To create curved wall, I cutted MDF by laser cutter with repeated slit lines, so called kerf bending.



Game Objects

I designed many game objects in Rhinoceros, 3D Design tool. Also using 3D printer,it means additive fabriation.

3D Printed Plunger

Plunger is a device for launching a ball. But it was a little big and not easy to get in Japan, so I made it by 3D printing in wildcard week. I made PLA plunger that tretches and contracts like a spring.



Fippers have to play the ball and flip away. The operation is, to press the button to flip, to release the button to undo it. I used solenoid to push the flipper, replace it by rubber band. I bought commercial switch (looks like in game center), designed 3D sockets and printed them.





The power is not strong… so I decided to use styrofoam ball instead of metal one.

Pop Bumper

If the ball passes certain points, photo reflectors detect it and pop bumper will bounce back the ball by solenoid placed under the play field. Pop bumper consits of 3D printed parts, spacer, and laser cutted acrylic plate on the top. (At first I made them all by 3D print, but it was hard to watch the ball move. Also the ball didn’t ride on it. So I added raster engraving by laser cutter to create a gap on playfield.)





I wrote detection and push-back program for my ATtiny3216 based board, using Arduino Language(show on next section).

Circuit Boards

I designed two circuit boards by EAGLE, and milled it by SRM-20. This part contains electronic design and fabrication and embedded microcontroller, interfacing and programming.


One is for Flipper with no microchip. It controls the flow of current to the solenoid by detecting the ON/OFF of the switch. I already tested it before, so I just arranged it for 3 photo reflectors and 2 switches.


The other is for PopBumper with ATtiny3216. I also made the testing board for photo reflector, so I changed its shape to be in the proper position. It is screwed to the back of the Playfield, the three photo reflectors face the surface. If the values they detect exceed the threshold, it will send a signal to the pop bumper’s solenoid to move.


int PR1_OUT = 0; // PA4
int PR1_IN = 1; // PA5
int PR2_OUT = 2; // PA6
int PR2_IN = 3; // PA7
int PR3_OUT = 4; // PB5
int PR3_IN = 5; // PB4
int SOL_OUT = 10; // PC0

void setup() {
  pinMode(PR1_OUT, OUTPUT);
  pinMode(PR2_OUT, OUTPUT);
  pinMode(PR3_OUT, OUTPUT);
  pinMode(PR1_IN, INPUT);
  pinMode(PR2_IN, INPUT);
  pinMode(PR3_IN, INPUT);
  pinMode(SOL_OUT, OUTPUT);

void loop() {
  digitalWrite(PR1_OUT, HIGH);
  int valPR1 = analogRead(PR1_IN);
  digitalWrite(PR2_OUT, HIGH);
  int valPR2 = analogRead(PR2_IN);
  digitalWrite(PR3_OUT, HIGH);
  int valPR3 = analogRead(PR3_IN);

  if (valPR1 < 870 || valPR2 < 870 || valPR3 < 870 ) {
    digitalWrite(SOL_OUT, HIGH);
    digitalWrite(SOL_OUT, LOW);
    digitalWrite(SOL_OUT, HIGH);
    digitalWrite(SOL_OUT, LOW);
    digitalWrite(SOL_OUT, HIGH);
    digitalWrite(SOL_OUT, LOW);

PR1_Out, PR2_out, PR3_out. Are they for pull up of photo reflector. 3 photo reflectors get values every loop, and if one of them goes below the threshold (photo reflector’s value depends on brightness and if the ball pass through on it, readed value will goes low), pop bumper’s solenoid moves 3 times.


For ease of maintenance, the enclosure and the board inside are made separately and can be easily removed. The photo is in the middle of development, but I was checking the size and actual behavior on it.


The main board is screwed to the back of the game board. All cable ends are connected with heat-shrinkable tubes and connectors so that they cannot be easily pulled out. I think it is my work for System Integration and Packaging.


The white cable connected to the mobile vattery, it doesn’t fixed to machine.

BOM(Bill of Materials)

This section contains answers for

  • What materials and components were used?
  • Where did they come from?
  • How much did they cost?
Part Material Quantitiy Price Subtotal Company/Shop
Enclosure Lauan Plywood 1820x910x18mm 1 5,000 5,000 ex.Rakuten
MDF 450x300x4mm 2 253 506 Tokyu Hands
Game Objecs PLA filament(orange) 1kg 1 2,880 2,880 Pxmalion
PLA filament(white) 1kg 1 2,980 2,980 Pxmalion
5V Solenoid SSBH-0830 3 1,200 3,600 TAKAHA
Transparent Acrylic plate, 100x100x4mm 1 647 647 ex.Monotaro
Switch 2 189 378 Sengoku
MainBoard Copper Board 100×150×1.6mm 946 1 946 Sunhayato
ATtiny3216 130 1 130 Digikey
PhotoReflector LBR-127HLD 50 3 150 Akizuki Denshi
ChipDiode 1000V1A GS1010FL 10 1 10 Akizuki Denshi
MicroUSB connector for power supply, MRUSB-2B-D14NI-S306 30 1 30 Akizuki Denshi
1uF Capacitor 1 1 1 Akizuki Denshi
0kΩ jumper 0.5 5 2.5 ex.Akizuki Denshi
75Ω resistor 5 3 15 ex.Marutsu
220Ω resistor 2.6 3 7.2 ex.Ali Express
1kΩ resistor 20 3 60 ex.Akizuki Denshi
10kΩ resistor 5 3 15 ex.Marutsu
L shaped 6 Pin header 2 109 218 ex.Switch Science
FTDI-Serial cable, 5V 1 1950 1 Akizuki Denshi
FlipperBoard Copper Board 100×150×1.6mm 946 1 946 Sunhayato
MicroUSB connector for power supply, MRUSB-2B-D14NI-S306 30 3 90 Akizuki Denshi
75Ω resistor 5 2 10 ex.Marutsu
10kΩ resistor 5 2 10 ex.Marutsu
L shaped 6 Pin header 2 109 218 ex.Switch Science
Mobile Vattery Canvas 3200mAh 5 2,500 12,500 cheero

Total prices is 31,527.7 yen. It’s about the same price as a Nintendo Switch.

What questions were answered?

How to detect ball hit?

→ I tried to use a metal ball and a copper foil sheet for electrical detection, but it didn’t work. Finally, we decided to use a styrofoam ball with a photoreflector to detect it.

Who can play? Playable for children?

→ It is difficult for young children. Control of ball launching is not easy.

What worked? What didn’t?

All function I made worked. Flippers with button, pop bumper with photo reflector are fine. But the flipper power was a little weak, and I couldn’t hit the ball back as far as I was supposed to. The score display and sound effects that I had wanted to create were not completed due to lack of time. It was difficult to make the ball fly where I wanted it to. It was necessary to change the position of the plunger and the guide rail.



The packaging for the part that controls the buttons and flippers, and vatteries are on the way at 1st spiral. I need to 3D print cases that fits them and can be placed under the board for 2nd spiral and so far.

Also I need to change place of photo reflectors. I put them all together at the top side of the game board, but If put one at bottom of board, it can detect player’s failure.

How was it evaluated?


Rico-san, one of my instructor played with it. It looks a little uncomfortable with acurate control, but could simple playing. I think it meets minimum function of pinball machine.

What are the implications?

  • Make plunger that works more properly.
  • Make more strong Flippers.
  • Change the place of photo reflector to detect player’s failure.
  • Refine packaging.
  • Add score and sound systems.

I feel it is just a first spiral. I want to brush up playfield and game object’s design. Fun game need score count and light/sound effects. There are many points to improve, I want to work on it slowly, over a long period of time.


The left is the initial concept and the right is the final result. I didn’t accomplish half of what I imagined! I realized that it is very difficult and take much time to create something, however, it is NOT impossible. This is one of the major things I learned at Fab Academy.






Pop Bumper

Circuit Boards (Main board)

Circuit Boards (Flipper board)

Last update: July 11, 2021