Chem E Car

Calorimetry Challenge

The goal of the Calorimetry challenge is to design, build, and test a calorimetry setup to measure the heat given off in a chemical reaction. Using an arduino, we need to code an immersion heater and stirring rod to control temperature. All of this needs to be done in a Styrofoam cup.

Final printed pieces

To start, we used Autodesk Inventor to 3D model the cover and stirring rod of the setup. The cover needed a place to hold the immersion heater and allow for a thermistor to pass through, while the stirring rod needed to mix the heat throughout the water. We based a lot of our designs on the example provided to us in class. The only inconvenience was trying to accurately measure all dimensions of the cup. It was time consuming, but we were able to do so using a caliper. The above mentioned thermistor needed to be wired into a voltage divider circuit and monitored by an analog pin on the arduino; the transistor-mechanical relay circuit needed to control the immersion heater through a digital pin on the arduino. The first time through, we accidentally forgot to change the units in Autodesk to inches. The piece printed in millimeters and was extremely small. Then we had to restart both pieces because we forgot to save the originals. On the right is are pictures of how the parts appeared on Inventor. Below is an image of the final printed pieces.

Next we completed the Thermistor Calibration. First we wired the thermistor on the breadboard and wrote a code to get corresponding values of Serial Monitor readings at various temperatures. Here is a copy of the code. We placed the thermometer inside the warm water and got the initial temperature (in degrees Celsius) and the Serial Monitor reading. As the water cooled, we gradually collected more data points. Once we had enough data, we graphed the points and found the equation y=0.352x-153.073. 

We finished wiring the general Arduino setup using this guide. The goal was to make a mock-up experiment where we'd light up a large bulb instead of the immersion heater. To do this, we wrote a program that puts heat in for 10 seconds, then stirs for 10 seconds, then puts out a temperature and total heat added in the Serial Monitor. Once the mock-up worked, we replaced the bulb wiring with the immersion heater one. The video of our experiment can be found here. The image below was our final successful setup.

Atlas Stones Challenge - Day 8

Final robot design

Final Design/Thoughts: We were finally able to run a trial with our robot. It successfully completed the course, and we received full credit. The robot finished the course in 2 minutes and 3 seconds; it was not as fast as we would have liked, but at least it ran smoothly. The programming worked well - there were no delays nor did the robot get confused.

Throughout this challenge, we definitely came across setbacks, but they were minor in comparison to those we experienced in past challenges. Building the structure was almost second nature after being the third time around, and coding was not too difficult. However, something that we definitely learned was to use our resources wisely and efficiently. Many Lego pieces were not available due to misplacement and "hoarding"... We had to make do with the few pieces we had, which in the long run, was a blessing in disguise; our robot was simple and effective. Next time, both of us hope to do improve the speed of our robots.

Video link: https://drive.google.com/open?id=0B_EDAYZEobu0eHBEUHdDbHJWcVU

Atlas Stones Challenge - Day 6

Today we continued to program. A few classes ago, we identified that the cause of jerking movements was due to an abundance of friction. We were able to eliminate this problem by adding a small piece that acted as a spacer. Doing this almost doubled our speed along with smoothing out the ride. At a point, this caused the robot to move too fast. We ended up decreasing the power so it would still follow the line. Once our robot is able to successfully complete the course, we plan on gradually increasing the power until it reaches its maximum speed.

Atlas Stones Challenge - Day 5

Today was another day of programming. Because of time limits, my partner and I decided to divide tasks; one of us programmed while the other worked on what goes on Blogger. An issue we dealt with today was the slowness of the NXT programming software. Much of the programming contains a similar pattern, so copy/paste would have been the most efficient route. However, whenever we tried to do so, the program took five times as long to load. Not as much progress as we anticipated occurred today. Next class we will continue the same process.

Atlas Stones Challenge - Day 4

Last class was the first trial day. We finished the general construction portion of the challenge, so we continued to work on coding. By the end of that class, our robot was able to lift and bring back one mass (50 grams); one third of the programming was completed. However, towards the last twenty-minutes, while running the track, the robot would make small, quick, jerking motions during turns. We knew that the distance of the wheels from the NXT Brick may have been causing a large amount of friction, but we were unsure if it was the cause of the jerking as well. For next class, we may rethink wheel placement and swivel size. We will definitely continue working towards a completed, efficient coding.

Atlas Stones Challenge - Day 3

Final robot design

Here is a picture of the final robot. As previously mentioned, my partner coded as I built, so we were able to test the robot as soon as it was completed. Something different I tried in terms of the winch was having it stretch from opposite ends of the robot. This would balance the mass distribution. I also added a 200 gram mass on the side of the winch and motor to counter the weight of the masses it'd be lifting. Based on some test trials, the robot's systems are running well and strongly. For the next class, we plan on trying to complete the programming. Maybe we will even be able to run our first trial.

Atlas Stones Challenge - Day 2

Robot by the end of Day 2

By the time I returned to class, my partner and I decided we would divide the work necessary to complete the challenge. I would be in charge of the design and construction of the robot while my partner would be in charge of the coding and actions of the robot; the coding in this challenge was much more difficult than before. I was able to complete the entire base of the robot within one class period. We decided that the foundation would be low to the ground to prevent it from tipping as we added upwards. Next class I plan finishing the rest of the body, mainly the winch.

Atlas Stones Challenge - Day 1

For the first day of the Atlas Stones Challenge, I was ill and had to miss class. Typically before the actual construction, we are supposed to evaluate the situation/challenge and brainstorm potential design ideas based on the requirements. Below is a Google Document describing the functions, systems, and integration of our robot. This was completed by my partner George Gikas when I was absent.

Transfer the Load with Winch Challenge - Day 5

Today was the final trial of the challenge. My partner and I had completed the initial requirements last class, so this time, we focused on gaining bonus points. Any team that lifted more than one mass would receive those points. Previously, our robot did not complete more than one cycle due to uneven weight distribution; the robot was top heavy. 

Below is a video of our robot completing two cycles of the challenge. It lifted a total of 400g (200g per mass). 

Final Thoughts 

I had more fun in this challenge than the first one; however, it was a lot more difficult. The robot was different than all the one's we created before, especially since it was not car-based. This time, we had to apply our knowledge of gear ratios in order for the robot to properly function, and we had to conduct multiple calculations.

Performance: As previously mentioned, our robot completed all requirements in order to receive full credit. Throughout the building process, we directed our focus to weight distribution and stability. We added counterweights to various places, allowing the mass to be lifted steadily. If we were to do this challenge again, we would more closely focus on the string that lifted the mass; it kept on slipping, limiting our robot to completing only two cycles.

Improvement and Learning: Thanks to this challenge, I am proud to say that I now understand the concept of "torque", for it is something I never understood before. To put it as my partner did, we also learned a lot about patience; taking apart and rebuilding practically defined our Winch Challenge experience. Because this trial was more successful than the last, I hope that my robot-building skills continue to increase as I move onto the next challenge. 

Transfer the Load with Winch Challenge - Day 4

Last class we completed the challenge! My partner and I fixed the sliding string by adding a second axle where it could loop over. We added a metal Lego hook to the end of the string to allow the string to smoothly return down. We also used the rubber Lego wheels as weights and balances. We noticed that each time we ran the program, the top motor would lean extremely far forward. Originally there were three support axles where it connected to, but we were able to find a location to insert a fourth one, greatly improving its stability. In order to receive full credit for the challenge, we needed to lift one mass up to the table, have the robot change directions while holding the mass, deposit it on a wooden block, and return to the ground. Bonus points would be awarded if the robot could lift multiple masses. We were very close to completing another cycle, but unfortunately it lifted the mass just short of the necessary height. Next class we still have another trial. By that time, we will try to enforce the robot even more, and hopefully receive extra credit.

Transfer the Load with Winch Challenge - Day 3

Design by the end of class

Last class was the first trial day. We were able to successfully balance our robot's systems by using what we learned from the previous unit. In the beginning of the challenge, each team was given two 100 gram masses to help with balancing mass distribution. We connected two long axles opposite to the end where the 200 gram mass was being lifted, and we hung the two 100 gram ones at the far end of the axles. Doing this greatly steadied our robot. As for programming, we were able to find decent power combinations to accommodate our gear ratio. With these two portions completed, our robot was practically set to complete the required actions; however, when put into motion, the string used to lift the mass kept on sliding out of place. Trying to prevent the string from slipping took up  most of our time. Unfortunately, due to lack  we missed our first trial opportunity. Hopefully next class we will be able to test our design.

Final code

Transfer the Load with Winch Challenge - Day 2

NXT Brick used for base

Last class was the second day of robot construction. We mostly worked on the base of the robot, which the two motors would rest on. The base's foundation was the NXT brick to counterbalance the weight of the mass the robot would be lifting. We attached Legos to the brick that acted as legs and axles that acted as a platform. The motors fit perfectly on top of the axle-platform, but the only problem was that it lacked stability, especially when pressure was put against it. We were told that for this challenge, we could only use the provided Legos and string. To further stabilize the motors resting above the structure, we used string to tie it to the base. By next class, we need to test whether or not the string interferes with the robot's movement and functions.

Transfer the Load with Winch Challenge - Day 1

Last class was the first day of the new Lego challenge. We are required to create yet another robot that lifts an object and moves it to another place, but this time, we are using different systems, including gears and pulleys. We are working towards finding an ideal gear ratio that maximizes angular velocity while still having enough force advantage to lift as many weights as possible (within given time limit).

Deliver the Golf Ball Challenge - Day 3

Today was the final day of construction. We were able to adjust the height of the claw so that it could grab the golf ball.

Final design

Final program

Here is a video of our final test run before our trial.

Final Thoughts:

The robot completed the course in 10.8 seconds. Due to some setbacks, we did not run more than one trial. The first time the robot finished the course, we left it as it is. Overall, its performance was good. The robot ran very smoothly, lifting the golf ball without hesitation and slipping smoothly under the bridge to deposit its load. We did not program the motors to full power because we did not know how much time we would have to test it. If I were to do this challenge differently, I would likely experiment with the power. 

I remember the time when I first used the Lego Mindstorm series to create a robot. It has been two years since then, and I am amazed in how much more sense it makes now. This was a great opportunity for me to confirm and improve my skills in coding, Lego building, and working with a partner. Something I plan on doing next time is to set a schedule for what I work on and when. That way, I'll have more time to test additional improvements to whatever I'm making. I hope there will be more opportunities such as this one. 

Deliver the Golf Ball Challenge - Day 2

Claw design #1

Today in class was the Trial 1 of the challenge. During my lunch period prior to class, I went to the Makerspace to work on the robot. I continued to build and program the robot up to where it was one command away from completing the challenge. The only problem was the elevation of the claw. It was less than a centimeter short of the height needed to drop the ball into the container.

When my partner arrived for class, we tried to increase the height of the claw, but doing this caused the ball to roll off whenever exposed to slight movement. Unfortunately, we ended up taking the entire claw portion of the robot off. Starting from scratch with the claw was not an easy task, especially since we felt pressured for time. Next class is the second trial. Hopefully we will finish by then. 

Here is the Google document that my partner and I plan on using to record any additional work. 

Deliver the Golf Ball Challenge - Day 1

Today we started our first engineering challenge of the year. Prior to this day, we practiced using the Lego Mindstorm Robot, learning how to assemble and program the machine to our desires. The challenge presented to us was called the "Deliver the Golf Ball Challenge", where we must design a machine that can move a golf ball from one place to another in the smallest amount of time.

Function	First the robot needs to stop at the pickup podium and capture the golf ball. Then it must back up from the loading area and pass under a wooden board. Lastly, the robot must move towards the side of the finish, head towards the bin, and deposit the golf ball into the container. All should be done in the shortest time possible without the builder touching the robot or the robot dropping the golf ball.
Systems	There are two main systems that must function flawlessly in order to complete the challenge. The first system is the chassis of the robot. There must be a strong base that is both short and compact so it may fit under the lowest point of the wooden board. Aerodynamics do not apply in this situation. The second system is a claw. The claw must be an appropriate height so it may reach over the loading and deposit areas. The claw must also be sturdy so as not to drop the golf ball when the robot is in motion.
Integration	*see sketch below*  As for mass distribution, the robot will have a heavier back side and a lighter front (where the claw is). This will hopefully be more balanced. For the forward and backwards torque, we will start by keeping it at the default 75% power. For turns, we will lower it to prevent the ball from coming off the claw.

Brainstorming sketch of design

We figured that the claw would be the most important part of the design; if it is unable to support the golf ball, we will automatically fail the challenge. Something we are working on is the stability of the claw, in other words, how it will hold up against weight and sudden movements. 

Close up of claw

Here is our robot by the end of Day 1. Next class, we plan on testing our design. Based on the test, changes may be made. 

Robot by the end of Day 1

Twitter

Last class, we made Twitter accounts as an extension for our blogs. The Twitter accounts give a different spin on engineering documentation, and it is a great way to connect with people we know and people we would like to know. I decided to create my Twitter accounts so that it is open for people who are interested in the activities we do in class. So far, we have posted things related to STEM, such as our roller coaster projects and maker faire projects.

Twitter iPhone app

Home page of my new Twitter Account

I have also created a widget linking to my Twitter. It's located on the right of this post. Check it out! 

Kraft Field Trip

Our second field trip of the year was to the Kraft headquarters, where we received an inside view of how everyday products are tested so they are perfect for sale. We were separated into several groups; I was placed in the Macaroni and Cheese group. We met a variety of people, all who specialized in a specific portion of the Mac and Cheese making process. It was a fascinating experience, and to think that so much work goes into the creation of everyday items is amazing.

Failed attempt at taking a group picture

My friend Briana and me

Guest Teacher - Prosthetic Limbs

Today we had the GBS librarian Mrs. May come in to show us her prosthetic leg. Eight years ago, Mrs. May hurt her angle while hiking. The injury caused a staff infection, which eventually led to the amputation of her left leg.  Within the time period between then and now, she has made many adjustments in her life that allow her to perform daily tasks.

Mrs. May describing her story

The leg is made of various materials ranging from titanium to carbon. Although the leg works well for her, versions of prosthetics are constantly being put out for use.

Ms. May's prosthetic leg