Design and Fabrication of Automated Embroidery Machine

Project Title

Design and Fabrication of Automated Embroidery Machine

Project Area of Specialization Mechatronics EngineeringProject Summary

The project revolves around designing and fabricating an automated stitching system. It works by producing stitched designs or embroidery patterns from any digital image, without any considerable human intervention. This is a product-based project and can be simplified into three major aspects; mechanical, electronics and software. The first aspect is associated with mating a conventional sewing machine with a 2-axis linear actuator mechanism, this acts as a replacement for manually moving the cloth about the needle, in order to impart the design the cloth is held firmly along the actuator by the help of an interchangeable hoop/ clamp. The second aspect revolves around development of a control system for automating the needle movement of sewing machine. As for guiding the actuators and continuously controlling the power delivered to the sewing machine control system, a program code translates the input image into vectors and transmits power to the respective motors accordingly. A digital image can be uploaded onto the software through an easy to use graphic human interface. This synchrony of 3 functions result in an effortless transition of a computerized image onto the cloth through intricate stitch patterns.

Project Objectives

-To design and develop a cloth movement mechanism with a minimum linear movement resolution of 0.5 mm till December 2019.

-To develop an efficient microcontroller firmware for controlling mechanical and electrical sub-assemblies till December 2019.

-To design and develop a control system for controlling the sewing machine at high speeds, up to 800 stitches per minute till January 2020.

-To develop a Human Machine Interface through which the user can control the machine till January 2020.

-To complete documentation at each phase of the project by employing project management skills.

-Completion of entire the project within a timeframe of 9 months.

-Total cost of the project to be kept under PKR 40,000.

Project Implementation Method

After observing a tailor embellishing a shirt using sewing machine, it occurred to us that in this advent of automation, this person still spends an extensive amount of time on such task. If this task would somehow have been automated, he would’ve spent this time on other important tasks. On top of this, the ever-increasing demand for embroidered adornments, kurtis, patterns etc. due to the rich culture of our country led us to the inspiration for this project. In the long run we could make an impact on both the economy of our country as well as create financial opportunities for countless individuals.

To realize this idea, we applied our engineering knowledge and project management skills. Our team consist of 4 persons from multiple disciplines of engineering catering the diverse technical requirements of this project. After problem identification, we started researching existing literature and performed a detailed market study. It was also made sure that documentation at each phase of project is properly done, therefore a Needs Assessment, Benefits Management Plan and Project Business Case followed by a Project Charter were drafted in the conception phase. After pitching various concepts to overcome the problem, the most appropriate concept was selected based on Analytical Hierarchy Process and SWOT analysis.

Entering planning phase, we undertook a very meticulous approach towards designing. Initially a Work Breakdown Structure was drafted, tasks were distributed among the team members accordingly. Critical Path Method was incorporated to prevent timeframe problems and Asana software was used for effective work management. In embodiment design, CAD model and circuit designs were finalized. Selection of most components required extensive design calculations. For instantaneous speed control and motor start/stop we designed a control system followed by a detailed selection of appropriate components. For controlling the cloth movement, a two-axis linear actuator was designed. 

In the procurement phase, we performed a detailed cost analysis and critical path method with the main objectives being the end product within budget and the deliverables on time. Procurement included importing parts which were ordered so as to not disrupt activities on the critical path.   

In the fabrication phase, individual components like electronic and mechanical parts were fabricated according to the design checklist and interfaced with a microcontroller to ensure smooth operation. For the machine to be interactable we programmed a user-friendly Human Machine Interface using Python. After this, all the components were assembled according to the designed route for assembly and selected tolerances. Trials were conducted to ensure that the software was compatible with our hardware and produced desired results.

Benefits of the Project

The motivation behind this project is simply the lack of any locally manufactured products and competition from the companies that sell sewing equipment or machines. Brief market studies in Karachi Saddar and Shafiq Morr (Hubs for retail outlets and OEM showrooms) proved that not only is there an absence of such a product, but those with similar functionality were either on an industrial scale or imported form international markets costing between 0.3 to 0.7 million PKR. Our project on the other hand costs a fraction of that sum while boasting additional features such as a completely modular design which can be disassembled and re-assembled, can be effortlessly installed onto any conventional sewing machine, is portable and takes up less space compared to the industrial sized automated embroidery machines and due to a minimal design can be easily manufactured on an assembly line. An entrepreneurial aspect of our project’s implementation is to target working women, that is it can be setup in cottage industries, giving them an additional means to generate income while uplifting the socio-economic conditions of said industries.  There are limitless untapped benefits linked to this project if implemented on a national level.

Technical Details of Final Deliverable

The final product is categorized into mechanical, electronics and software part as following:

Mechanical part:

A lightweight linear actuator mechanism is designed for rapid horizontal movements of clamped cloth. The mechanism movement is controlled through NEMA 17 stepper motors, one for each axis. Timing belt is used for converting rotational motion of stepper motors into linear motion of the mechanism. 3D printed parts are used to rigidly constrain the mechanism while close tolerances were set so as to achieve a stable structure. The entire mechanism is modular and thus adjustable according to requirement including the hoop onto which the cloth is clamped. Current configuration of mechanism provides a cloth stitch area of 280mm x 280mm.

Electronics part:

Sewing machine will be powered through a single-phase universal motor. Universal motor is controlled in a closed feedback loop by using PWM Chopper control method to maintain synchrony between vertical motion of needle and horizontal motion of cloth while operating motor at user defined speeds. The entire control logic consists of PI controller, power driver circuit and a rotary encoder which is attached to the motor spindle for feedback. PI controller sets the output value according to the measured encoder pulses and user defined speed value, the resulting PWM signal from Arduino is then transmitted through an optocoupler to the power driver circuit. In the power driver circuit, AC line voltage is first rectified and then switched by a power MOSFET, which is driven by signal from optocoupler, this in result generate time varying voltage for the motor.

Synchrony between needle and actuator movements is maintained so that actuator does not move while needle is inside the cloth. This synchrony is achieved by transmitting real-time information of needle position to microcontroller for triggering actuator movement in the right moment. For reading needle position an incremental encoder is developed using two phototransistors and an IR LED.

Software part:

Firmware for Arduino is developed on C-language. Main segment of the code is related to controlling movements of actuator mechanism, which is achieved using principles of computer numeric control by converting the user fed g-code into steering pulses for stepper motors. Other features of the code include PI controller logic and interfacing with needle position sensor using interrupt.

Human Machine Interface is developed on Python 3.x and uses Tkinter for GUI, it can run on any computer or embedded computer like Raspberry Pi. The main features which application offers are setting the speed limit of stitches per minute, thread colors required according to the fed image, notify when thread change is required, setting workable area of cloth and manual overriding functions during the process.

Final Deliverable of the Project HW/SW integrated systemCore Industry OthersOther Industries Manufacturing Core Technology RoboticsOther TechnologiesSustainable Development Goals Decent Work and Economic Growth, Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	33199
Sewing machine	Equipment	1	6500	6500
Stepper motor NEMA17	Equipment	3	350	1050
Stepper motor NEMA23	Equipment	1	1730	1730
Stepper motor driver DRV8825	Equipment	3	220	660
Stepper motor driver TB6600	Equipment	1	1150	1150
CNC shield	Equipment	1	220	220
Smooth rod	Equipment	4	900	3600
GT2 belt	Equipment	3	250	750
Pulley and bearing	Equipment	1	2389	2389
3D printed parts	Equipment	1	7800	7800
Arduino Uno	Equipment	1	800	800
Wood work	Equipment	1	4000	4000
Electronics(resistors, capacitors, transistors, diodes etc)	Equipment	1	660	660
Sewing machine cargo	Miscellaneous	1	1890	1890