April 2024 UFO

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  • Soft Baked Cookies
  • Trading Cards

Please login to view codes if you received this months UFO.

Subscriber @tsiolkovsky created a neat trading card holder for the top of the printer to hold the card for the sample you're printing with!
Download Card Holder

Filament Samples

All filament samples are at least 20 meters in length (actually more, I increased the length to eat up the extra filament being left behind on the rolls)

Those looking for a sample spooler, MadMonkey designed this one and it's been my favorite so far https://www.printables.com/model/36621-expandable-sample-spool-holder

DSK has also made a sample spool specifically to fit the samples from the new machine: https://www.printables.com/model/428314-sample-spool-snap


150MM Digital Calipers

It's been 4 years since I included calipers, figured it was about time to include them again =P


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+Nano version of the UFOs received an ESP32-WROOM

Coin Sorter/Counter

Files on Printables
Arduino Code

I thought this would be a fun project as the only other time IR sensors have been used is with the line following robot.

A couple notes:

  1. While planning out this project I miscalculated how many wires would be needed, I included 20 but realistically it needs 24 - =(
  2. It could really use a reset button... something I didn't think about when planning it out.
  3. As of this writing I haven't been able to figure out a good way to debounce the sensors - sometimes it will read more than 1 coin when only 1 coin passes because it reads too quickly >.< - working on it still but code is functional.
  4. I MAY relocate the sensors in the future if time permits. I just think they may work better under the track rather than in the tubes.


  • 4 x IR Sensor Modules
  • 128x32 OLED SCREEN
  • Stepper Motor
  • Stepper Motor Driver
  • Mini Breadboard
  • 10 x M3 Bolts
  • 10 x F to M Jumpers
  • 10 x F to F Jumpers


+ from Driver to VIN of Control Board
- from Driver to GND of Control Board
IN1 from Driver to D27 on Control Board
IN2 from Driver to D14 on Control Board
IN3 from Driver to D12 on Control Board
IN4 from Driver to D13 on Control Board

VCC to Pin D26 on Control Board
GND to GND on Control Board
SDA to Pin D21 on Control Board
SCL to Pin D22 on Control Board

Mini Breadboard:
The way the breadboard fits into the case, rows are shared connections.
3.3v from Control Board to top row of Breadboard
GND from Control Board to bottom row of Breadboard

IR Sensors:
All VCC goes to the top row of the Breadboard
All GND goes to the bottom row of the Breadboard
Quarter Out to Pin D15 on the Control Board
Nickel Out to Pin D4 on the Control Board
Penny Out to Pin D16 on the Control Board
Dime Out to Pin D17 on the Control Board

For some reason D2 wasn't working with the sensor so I skipped it, but tried to put all the pins on the same row and next to each other.

After everything is hooked up and programmed and powered on, the sensor boards will probably be reading HIGH as if it is detecting something. There is a potentiometer on the boards, rotate them counter clockwise until the right LED turns off (when looking at it from the sensors towards the pins)

I will get a wiring diagram and video up ASAP.

Programming the ESP32-WROOM Boards:

There are 2 ways you can program the board.

Arduino Web Editor:

One way is to use the Arduino web editor. You can create a project in the online editor and copy the code into it. Just follow the websites directions on getting the needed plug in installed. The board you would select is the esp32 dev module

Locally on PC:

First you will need the Arduino IDE installed on your computer. Which you can install from 
https://www.arduino.cc/en/software . If you are using windows 11 I would suggest to download and install the legacy IDE version as new one gets some access denied errors.

Once the IDE is up and running you will need to install the esp32 board.

First thing you will need is to install the Espressif esp32 board library. You can do so by following the tutorial on the website below: [Note for our board select the esp32 dev board]


After the board is installed you can open up the .ino file for the project.

You can the select the board Esp32 Dev Module and the correct port and click upload.

This should compile the code and send it to the board for you!

You can earn 5% of every renewal for referral subscriptions each month by referring new customers. Simply visit https://www.alien3d.us/affiliate-area/ to see access your link or code! Contact me if you'd like a custom code instead of the auto generated one.

Comments 10

  1. I have everything wired up as noted. I have the code on the arduino. I can trigger each of the coins and see them count. However, the motor doesn’t turn on. I have double checked all motor connections. Am I missing something?

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            Sorry, I didn’t get a notification that you replied back. I’ll send another board and motor, maybe one is bad ๐Ÿ™ sorry about that

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