Coin Pusher machine

thingiverse

This is a mini coin pusher machine. It's designed to play with 1 euro cents and 2 euro cents coins, but you can use any coin with similar dimensions (15-25mm diameter and 1.7 - 2mm height). I built it around what I had lying around, especially a NEMA 17 stepper Motor, a stepper driver salvaged from a 3D printer, and an ESP8266. These might not have been the best choices, but I wanted to stick with what I had on hand. You can see it in action here: https://youtu.be/FeP9LR1BNm0 ## BOM - 12 M3 X 30mm screws - 4 M3 X 10 mm screws - 4 M3 X 20mm screws - NEMA 17 stepper motor - Stepper driver (Pololu or equivalent, the application is really simple, anything capable of making a stepper driver make 360° turn with decent torque is sufficient) - ESP8266 or any micro controller you are used to (Arduino) - Power supply around 12V - 1A. I used a 15V .4A from a broken hair clipper. Not ideal but it works. - All the printed parts ## Printing - Dozer might need support for the slide under the plate - I've tried different orientations for the right and left sliders, I printed them "facing up" so I didn't need supports but you might get away printing them "flat" with supports. - Every other piece: Shouldn't need any particular attention. - I mostly used .2mm layer height and a .6mm nozzle. These shouldn't influence the result. ## Assembly - Start by assembling the motor to the motor support. - Then screw the motor support to the base plate. - Add the pacer and the crank to the motor shaft - Start screwing one of the side guides on the base plate, slide the dozer sideways and then screw the other side. - After that, there's no particular order to mount all other pieces, I hope it is quite intuitive. ## Electronics - Wire your stepper driver to the micro controller - Plug the stepper motor to the stepper driver - Add power ## Code ```c++ #include <Arduino.h> #include "BasicStepperDriver.h" #define MOTOR_STEPS 200 #define RPM 15 //120 // 1=full step, 2=half step etc. #define MICROSTEPS 1 #define DIR D8 #define STEP D7 #define SLEEP D6 BasicStepperDriver stepper(MOTOR_STEPS, DIR, STEP, SLEEP); void setup() { stepper.begin(RPM, MICROSTEPS); stepper.setEnableActiveState(HIGH); } void loop() { stepper.rotate(360); } ``` I used the "StepperDriver" by Laurentiu Badea library in Arduino IDE. Link to the Github: https://github.com/laurb9/StepperDriver Read the readme file for more informations, especially for wiring: https://github.com/laurb9/StepperDriver/blob/master/README.md ## Misc thoughts Obviously there's a lot of room for improvement, I'm not really familiar with 3D CAD software. Some choices are limited by my 3D skills. I tried to make everything simple to print (no supports needed) and I split some parts for ease of prints and modification (especially around the motor so you can use other kinds...). I used Tinkercad - once again, maybe not optimal but it was convenient. Feel free to remix, edit, modify, make your own version. Some pictures of the guts of the machine: https://imgur.com/a/489ZpE2 Source if you want to remix or customize: https://www.tinkercad.com/things/e6SbyxiWyx2