Project Multicolor 3D printing

• 3D Printed products are usually monotonous in colour
• Inability to print object in a variety of colours in the same build
• Enable products to closely emulate the original and make it consumer friendly

• To provide a proof of concept of mixing of heated filaments in the extruder to achieve varying grayscale outputs
• To show that multicolour 3d printing can be achieved at much lesser cost than that is commercially available

Code arduino to run stepper accordingly
File name : decoder.py 🔗
Libraries used :

• numpy pip install numpy
• PIL pip install Pillow
• pyfirmata pip install pyfirmata
• scipy pip install scipy

Input : A single color gray image or gray intensity (0-255)
Output : Two stepper motor extruding PLA (black and white) at speeds to give the input grayscale variation

• resolution : how close to input gray image // high resolution increases voxel length is not good
• min_speed : maximum time delay for nema17 stepper motor maximum time delay minimum speed
• step : array of white and black step number

def create_image 🔗

Creates a test image not required to be executed download image from this link and save it in same directory of python file(decoder.py)

def get_intensity 🔗

Fetchs gray scale intensity of image assumme image to be mono-colored for testing purpose just input required gray scale intensities in color_grad variable at At line 140 of decoder.py . color_grad is an array containing different voxel color informtion for one voxel just input one item in list color_grad = [200]
For Example

color_grad = [0]*10 + [128]*5 + [200]*1 
This will print out 10 voxel of gray intensity 0 , 5 of 128 and 1 of 200

def motor_white / def motor2_black 🔗

Takes N number of steps to be executed as variable and runs the stepper for N times

def step_genertor 🔗

For a certain gray value we figure out how many steps should black/white motor runs say W,B
Divide W,B as sum of W = w 1+ w 2+ w 3 .... and similarly for black
For particular gray scale returns an array of which have reduced number steps in format [[w 1,b 1],[w 2,b 2]........] where w,b correspond to white and black .

White stepper runs w 1 steps
Black runs b 1 steps
again
White runs w 2 steps
Black runs b 2
goes on .............

def pixel 🔗

Same as step_generator just cares of edge cases and gives final array of steps required to print one voxel

def printer 🔗

Actuates motor and start printing . Receives one array needed to print a voxel

• Install Python 3.6(Python3.+ would work) and pip Check Here for installation
• Download project
• Open cmd in project directory Blenders>pip install virtualenv
Blenders>cd venv/Scripts
Blenders/venv/Scripts>activate.bat
Blenders/venv/Scripts>cd ..
Blenders>python decoder.py Run this command while you are connected to arduino uno check port by default its COM5 in decoder.py line 150 change it as in your System

Arduino Uno

• Ravindra Sagar ( BTech ME , IITB )
• Nishant Venkatesh ( BTech ME , IITB )
• Sujeet Singh ( BTech ME , IITB )
• Prakhar Joshi ( BTech ME , IITB )
• Maurya Patel ( BTech ME , IITB )
• Sheryas Bhatt ( BTech ME , IITB )
• Himanshu Singh ( BTech ME , IITB )
• Aman Gautam ( BTech ME , IITB )