How I made CNC drawing bot in 21 days .

Cnc drawing bot is my first mini-project I did in my second year of engineering

There were many difficulties, but we managed to complete the project in 21 days and we were lucky enough that it got selected in the yearly technical fest we have in our college.

In this article, I will share the journey with you and also tell you how we solved calibration problems and what we intend to do with it in the near future.

Project Abstract

We have observed rapid growth of technology, the usage & utilization of CNC machine in industries were increasing to automate manufacturing process. We are fabricating low-cost CNC machine to reduce cost and complexity of the machine. The motive behind our project is to design a low-cost CNC drawing bot, the lower cost is achieved by incorporating features of ATMEGA 328 controller in an Arduino. We have used a G code library for whole system operation.

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Technical Approach

A pen touches the surface & prints the pixel for logic 1 and lifts up in the air for logic zero & the base changes its position for next commands through the input. our plotter is one-dimensional (1D) plotter that uses a single ink to print and in one dimension only.

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Working - The G code is interfaced with ATMEGA 328 microcontroller which is used to convert the code in convenient controller code i.e. USB to serial controller. Hence it acts like interfacing module between laptop input to Arduino. The G code is passed to stepper motors through serial communication which converts the code and as per the coordinates, the stepper motor moves accordingly. We need three axis’s X, Y, Z which operates the motors.
z-axis - to control the movement of pen vertically upwards or downwards
y-axis - to control right movement
z-axis - to control left movement

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PROCEDURE in BRIEF -
1.Dismantle the stepper motors from the DVD drives.

2.Adjust the printable area of 4 x 4 cm.

3.A temporary chassis of cardboard was made to test the initial drawings.

4.Separate motors were used at first which led to calibration.

5.Final chassis designs were made, acrylic was chosen as the chassis material.

6.Beard-board was replaced by a custom designed PCB.

7.Final calibration was made to the motors and the arm.

8.A dedicated IP cam, projector was utilized to project the Drawing live on a bigger screen.

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Social Benefit:
CNC bot is extensively used in industries, for wood carving, industrial manufacturing processes, it also used nowadays in health sciences and for sculpting statues.

The scope of the project in future :
Bringing the CNC bot to a larger model with reduced cost can truly help small-scale industries and the 3d printing industry.

Further Improvements:

• Our intention is to make a smaller bot at first, and once we are confident of the mechanical aspect we are thinking to take it next level (large size, more accuracy, direct link from inks cape without burning the code.)

Program Code (Assembly / C file)

https://codebender.cc/sketch:146939?referrer=mi.vasilakis

PROJECT COMPONENTS AND EXPENSES

COMPONENT	EXPENSES(INR)
1. DVD writer x 6	5000
2.Arduino uno	450
3.small servo motor	215
5.PCB board	115
6.Acrylic sheet	200
7.Male headers and other mechanical parts	500
8.stationery.	470
9.Encloser box	350
10.Miscellaneous	390
Total	INR - 7690(117.472 USD )

Working video

References
http://www.instructables.com/id/CNC-Robot-Plotter
https://en.wikipedia.org/wiki/MakerBot

Image Sources: All images were taken from my camera.