3DWelderPCB

3DWelder

This is an overbuilt 3D pen designed to be used for "welding" 3D printed parts together using 1.75mm filament. This project is funded by Hack Club as a part of the Highway program.

Keep in mind for time being PCB is not working, I'll update soon.

This design uses a CHC Pro hotend and a custom Orbiter extruder adapted to use a DC motor. This DC motor's speed is controlled by a drill trigger adapted into the handle. It has a small screen and a rotary encoder for adjusting and showing the temperature target. The whole thing is powered by a drill battery to make it more portable and easier to use. This project is currently completely untested.

Why?

So, why did I choose to make this ridiculous thing anyways? Well, the best way to join 3D printed parts together if they can't be screwed is by literally joining them together with the same plastic they're made of. This can be very difficult with a normal 3D pen though, as they're quite low powered and actually can't even melt many higher temperature plastics. I wanted a solution to this, so I decided to basically make a regular 3D printer extruding setup, but make it portable. It has some other uses aswell, if you use EVA filament, it could function essentially as a hot glue gun. It could also theoretically be used as a 3D pen, but not that well.

PCB

The pcb was designed using KiCad, and it is only 2 layers. The pcb controlls everything except for voltage control and the motor, which is controlled by the drill trigger. It uses screw terminals and jst-xh connections. The brains of the whole thing is an Arduino Nano.

Wiring/Assembly

All 3D printed parts screw together using M3 heatset inserts and various M3/M4 screws. For wiring, 2 spade connectors are used as terminals on the battery. From there, there's 2 ways of wiring everything else. You can either put the buck converter inside the space above the battery, then have wires coming off of that to the drill trigger and pcb, or have the buck converter up by the pcb, then have wires going back down to the drill trigger. Having the Buck converter in the handle is much cleaner, but may be very difficult to fit inside that small space.

Code

#include <PID_v1.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <Wire.h>

//Defines screen width/height
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32

//Not using a reset pin
#define OLED_RESET -1

//Creates a display named display, gives it parameters
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// EC11 code
const int EC11PinA = 8;
const int EC11PinB = 7;
volatile in encoderPos = 0;
in lastEncoded = 0;

/* -----------  USER SETTINGS  ----------- */
const int   thermistorPin   = A0;
const int   heaterPin       = 6;     // PWM pin

This is the firmware to be uploaded to the Arduino Nano. It's purpose is for PID control of the heater via the thermistor readings and mosfet. It has temperature control via the EC11 rotary encoder, and the temperature target and current temperature are displayed on the 0.91 inch OLED screen.

BOM

Total(No shipping/taxes): $148.12
My Total: $157.54 (with shipping/taxes, excluding owned items)