Projects
B.Tech Project: Concrete filled steel tubes as machine elements
As a part of my B.tech Mechanical Engineering course, we did a project in which we analyzed if the buckling strength of a hollow steel tube can be increased by adding an inexpensive filler in the core like concrete.
The experiments showed that the concrete filled steel tube with held a bending force ten times larger than the same hollow tube.
For the detailed report and explanation, click here.
The entire project is explained in a different web page which can be viewed by clicking here
Letter of appreciation from my professor: click here
Motor Propeller system for data generation
I did this project under (Prof.) Dr. N. R. Raykar during my 2nd year's summer vacation.
The system has a motor and a controller. Once the system is programmed to run in a certain way, the sensors in the device monitor various parameters vs input/time.
The parameters that are monitored are- Input, Motor speed, Thrust generated by propeller, and the current drawn by the motor.
click here for a detailed pdf report, here for additional pictures
Who doesn't like springs? Nice elastic members which can give force when required or store mechanical energy for you. They are pretty simple yet amazing.
But when it comes to buying springs, it is not at all an easy task. Especially if you are looking for springs in small numbers and/or you are on a budget. I had previously made an apparatus to check the spring constant. In this project, I made a spring bending machine.
This machine can create a spring with any diameter that you would like with any number of turns. It is a bit different than the machines shown for hobby use created by our friends like Jiri Praus. One of the major cons with his machine was that it required two stepper motors, stepper drivers and micro controllers. While I am comfortable using stepper motors and micro-controllers, I wanted to make a machine without them to keep the cost low. My machine resembles the process used to manufacture springs in large numbers. A wire is forcefully extruded through a hole and it is forced onto a roller or a metal wedge which bends it as soon as it exits the hole.
In my view, the gripper is by far the most complicated of all the components of the machine. It is important that this gripper grabs the wire hard enough to push it against the heavy force required to coil the wire.
The gripper, like all other parts of the machine, is 3D printed. The hardness of the plastic is much lower than that of the wire. It simply cannot grip the wire tight enough to be pushed against large force of bending the wire.
To solve this issue, I have created slots to add box cutter blades in the slots to grip the wire. When the force is put on the extruder, the force is transferred on the wire which in turn helps the blades grip wire better. To fine adjust the protrusion of the blade, there is a bolt at the back of the blade. When the bolt is tightened, the blade would be pushed on to the wire.
Spring turning machine
Spring testing machine
1. While searching for springs online, I quickly realised that most springs that are sold online are no brand and subsequently have no data connected with them. Particularly, they lack the most important information about the spring, its spring constant, which gives the relation between the compression and force applied
However, it is much easier to make a spring youself. You only need some way to accuratly and repeatably measure the spring constant. And for that I made this spring testing machine.
The design is published on instructables and is also a featured article. The article also has all the calculations required for stepper motor and lead screw.
2. My machine, like any spring testing machine has two main components, one that measures the displacement and the other that measures the load (force). The displacement is controlled by a stepper motor and a lead screw. The stepper motor's rotation can be precisely controlled and we know the pitch of the lead screw. So for every step the motor takes, the microcontroller calculates the displacement and determines how much the plunger has moved.
The load measure is done by a 1kg load cell which is petty standard. The mirco controller puts out the value of the position and the load. But instead of loading the value in the Arduino serial monitor, I decided to use the PLXDAQ tool which allows me to import the values directly into MS Excel.
This opens up a lot of many ways to display the data where it is more intuitive. I plotted the displacement and the load cell value which gives a nice linear curve as expected.
In this case the we can see that the spring developed a force of 400g which compressed by 15mm. This means the spring has spring constant value of 400g/15mm= 26.67g/mm
Stroboscope
This was created with arduino nano as the controller.
Its internal timer was used to create precise flashing frequency. The light used was extracted from a commercial light which run on 32V. Two potentiometers (fine and coarse) are inputs to control the flash frequency.
A OLED display showed the frequency of the flash. The system is designed to run on 5V DC from any micro USB port which means it can also run on a standard power bank.
Tachometer
Tachometer is a standard equipment to measure the rpm of any rotating disc or shaft. This project turned out to be great success. It is very compact and accurate and can easily compete commercial alternatives. Like stroboscope, it is also designed to run on micro USB.
Care was taken to make its shaft as friction free as possible. This was accomplished by making sure all sliding contacts were metal
click here for instructables link and click here for YouTube link
Cycle speedometer
This was my entry on the internet with my project. This is the most successful project on instructables with over five thousand views. It is also a featured project i.e. the editors selected it one of the projects worth viewing.
The system was remarkably accurate. The accuracy was checked by cycling parallely with a scooter. The readings matched accurately.
Along with the speed, it also measures the distance traveled.
click here for instructables
DIY inclinometer
I made this project with MPU9250 board which has an accelerometer, gyroscope and a magnetometer along with a temperature sensor.
I have made dedicated articles on this project on instructables and on YouTube. The code is attached on the instructables article.
Click here for the instructables link and here for the YouTube link
DIY Compass
This project was used my utilizing the same hardware as the one used on the Inclinometer which is mentioned above.
The magnetometer of the MPU9250 was used to determine the direction.
The code and the detailed procedure for making this is on my instructables page which can be accessed by clicking here or on my YouTube page which can be viewed by clicking here.
Small Wind Tunnel
This was also one of my ambitious projects.
As everything is in tight budget, all the components were designed and fabricated with easily available resources.
The highlight of the project were the tubes that were placed before and after the test space so that the disturbance from the fan and the intake air can be minimised. They were made from normal drinking straws. After a lot of trial and testing, I was able to create rectangular blocks which were then fit in.
Also, to generate smoke, incense sticks were used. For that, a separate combustion chamber with its own fan and insulation was designed.
My Lab bench power supply (Inspired by GreatScott!)
My Fume extractor
Self made enclosure for my 3D printer to prevent dust during printing
My makeshift light setup; made from scarp wood and hardware supplies
