The future of metal casting: giving physical form to digital designs

Today was the day I gave physical existence to a purely digital entity.

My Casting Design and Simulation class has been dealing with the gating (channels for metal delivery) design for this part for a few weeks now:

Those thin features on the side are 1/16″ thick.

The students collectively created a design:

CAD view Part Design

And we turned it into a mold:

CAD view half mold
Only half shown here, but you get the picture.

I created a simulation of the fluid flow and metal solidification behavior of this digital design:

Using these simulations, we also predicted where porosity defects were likely to occur:

One spot at the top, and one spot in the dead center.

Alongside these models, we got the mold design 3D printed, allowing us to exactly replicate our digital design. Up to this point, everything existed solely on a computer. Here was the first physical manifestation of our process.

Down there in the shadows are some very, very thin features that we were convinced would never work. They’d either get burned through or just snapped off entirely.


The mold halves were put together, to prepare for pouring.

After we poured iron into the mold and gave it a little bit of time to solidify, we opened the mold to see our results:

Yeah, probably still a little hot.

The sand and metal were still so hot that we could actively see the binder burning out and the sand dropping off as it lost all strength:

The slots came out!

Here’s the money shot–a large porosity hole exactly where the simulation predicted:

So not only have we now confirmed the accuracy and validity of the simulation, we have given exact physical form to an object that had only before existed in a digital space. This is the future.



Totally Terrific Teaching

The readings this week offered some valuable advice on how to develop an effective teaching mindset. Admittedly, most of it seemed rather intuitive – not because I’m a particularly talented teacher – but because I’ve been privileged to experience high quality teaching throughout my academic career. My best teachers were not the ones that conveyed information the most effectively. The best were the ones who could infect me with their enthusiasm and passion for the subject matter. With that sort of fuel, I think anyone is capable of directing their own learning faster and more efficiently than someone else would be able to teach them.

As a teacher, I try to be less of a source of information to my students than a resource to challenge their thinking. Rather than confirming something for them, I think it is far more valuable to present them with a challenge that would allow them to confirm or invalidate their suspicion/theory.

There are a few reasons I think this works well for me. I am 24 and my students are 20 – 21. I’ve always been very clear with them about my level of expertise and inexperience as a teacher. The students have a very realistic expectation to match and even surpass my understanding of at least some class concepts and materials. I think many students find the prospect of educating their teacher enticing. After all, what pupil doesn’t want to become the master?

What to learn from Alan Alda

Imagine that you are a good researcher who just got his PhD and made some highly cited publications. You tell yourself “Okay, I am very ready to get a tenure track position in a reputable university”. You apply for such a position and eventually you get the position. Preparing for the semester, you make brochures for the course you will teach, the class is full and many students still want to register the course, every thing seems to be perfect till now. However, after two lectures, the number of students who attend decreases and by the course drop deadline, you find only one fourth of students who registered the course will continue it.

A nightmare scenario for a new professor. What’s happened I believe I can understand multiples of the information I give in class. I avoided tough topics, why students left my class?! A lot of questions hit your mind, but let conclude all these in just one question:

Is a good researcher a good teacher ?

The answer is not always true. One of the pioneer in noticing this was Alan Alda an actor, director and writer, and a six-time Emmy Award and Golden Globe Award winner.  He has had a lifelong interest in science. In 1990, he began his TV program “Scientific American Frontiers“.  The program continued until 2005 and mainly focused on informing the public about new technologies and discoveries in science and medicine. After interviewing hundreds of scientists, Mr. Alda became convinced that many researchers have wonderful stories to tell, but some need help in telling them.

This gave the idea to Mr. Alda to establish Alan Alda Center for Communicating Science. The center aims to enhance understanding of science by helping train the next generation of scientists and health professionals to communicate more effectively with the public, the media, and others outside their own discipline. The message of Mr. Alda can be concluded in making a good communication with your audience, rehearse on the best way to deliver the same piece of information to different audience. For example, old people, young children, people very far from your field. By doing this, you ensure that you get the simplest way of illustrating something. There is a well known quote that says “If you can’t explain it to a six year old, you don’t understand it yourself.” 

Other advice from Mr. Alda is to be always able to improvise. This comes by a lot of training and practicing. It is not good to memorize every word you will say in your lecture in advance, but you need to arrange your thoughts in a way that makes you cover everything in a timely and effective manner while ensuring that your audience are understanding what you say.

I think this specific way of science communication should be used by professors/ teachers in their classrooms. It is not hard but only requires training and preparation.

Teaching as Self-discovery

One of my favorite teachers told me years ago that teaching was a chance for you to reinforce material you have come across before, to solidify previous knowledge, to assign readings that you yourself have wanted to read. This way, the teacher is understood as a student who learns alongside his or her students. Teaching was thus a process of self-learning, self-discovery. Does this seem counter-intuitive? Are we not supposed to “know” our material before teaching it? Well, yes and no, it seems. We “know” enough to garner the respect of our students, that they acknowledge that the teacher knows more than them. But we certainly don’t know our disciplines as much as we feel we aught to, thus making sense of Einstein’s pithy statement “The more we know, the less we know”.

Sarah Deel’s “Finding my Teaching Voice” was a poignant personal narrative of her own journey towards finding her own voice as a teacher. She ultimately discovers that by discovering her ‘teaching voice’ she herself was ‘liberated’. This was not the feeling I had teaching for the first time at VTech. I recently taught my first undergraduate course last week. I have spent the semester watching other teachers and taking mental notes on where they are succeeding and where I need to do better. Yet when the moment came, I found myself giving a 1 hr and 15 minute powerpoint presentation — with an 11 minute movie clip — because giving presentations was what I knew as a student. It was where “my voice was”; but I didn’t feel liberated as Deel did, I felt ‘stuck’ in the mode of presentation. I later realized that while I did a reasonably good job at asking the students questions and getting them to respond, I did not really “teach” the material; I simply gave a presentation of the material. The next class, I watched how the professor “taught” the class. She didn’t speak for more than 15 minutes, breaking up the class into group discussions, journal entries and a debate. She taught, I presented; and she did it with a lot less stress! Fowler’s advice rang true and clear “Teaching is not all about the teacher; that is, teaching is not all about you”. Instead, the professor was what Fowler calls a “guide” and “facilitator”.

The professor who watched me later said that I shouldn’t beat myself up too much, that I did very good for my first time, and that “you looked very comfortable up there! If you have managed to get that out of the way already, you are on a great start”. While I was happy to hear positive reinforcement from the professor, I still felt deficient in something. But one thing rang true: I had to be myself. Teaching forces you to open up and take a risk in being yourself. There is almost no other way to do it. You figure it out very quickly in front of your students.

One important nugget I took from Deel regarding successful teachers:

“They [the teachers] explained their strategies to their students. The context of the particular classroom was very important; since the students in each class understood their teacher’s philosophy and evaluation style, they were able to learn from the teacher’s responses to their writing.”

Quickly: Fowler’s “Authentic Teaching Self” was remarkably useful and terse. This type of nuts and bolts approach to providing quick advice to aspiring teachers works like an effective tool-kit that repairs minor damages. I particularly appreciated the “physical aspects” section where teachers are advised to ‘warm up’ their body and mind prior to teaching. I do precisely the types of strategies she mentioned in order to remove nerves. It actually works! Warming up the vocal box is useful too.

There are a lot of different ideas floating in this piece. Apologies for the obvious disorientation in this post. I’d appreciate thoughts/reflections on something/anything here.

Will technology guide your teaching?

Teaching philosophies are vital to the success of the students. As engaged as the instructors are, the more positive outcomes come out of these classes. This week has been a week I’ve been thinking very deeply about teaching.. In relations to the readings and striking a balance with my own, already present teaching philosophy.

I’ve been a true believer that people can always improve and build on an already present teaching philosophy, to include a lot to engage students in the most cutting edge manner. Sometimes I’m really sold on the cool things technology can do for teaching. I love technology, I’m attracted to it, and I think it’s awesome. I’ve had classes that had awesome teachers who relied less on technology, while some relied on PowerPoint. There were others that had a lot of technology, but couldn’t engage their student’s interest in the class. At the end of the day, my peers and I got interested in what we could get in touch with… In other words, if learning this course could help us be better in our field… If we knew the benefits, if we knew what to do and how to accomplish our dreams… we did. It really helped to have good teachers, who could really teach. Who cared for their students. Who were interested in their students success.

On that note, part of my teaching philosophy isn’t to impress my students and give them technology. Technology can support their education, but it doesn’t have to be the full thing. In both Sarah Deel’s essay “Finding my Teaching Voice” and Shelli Folwer’s “The Authentic Teaching Self and Communication Skills” the struggle is quite clear for how to both establish control and interest in classrooms without micromanaging students and being strict.  Apparently, this struggle is more well-known among females than males, but it exists. A lot of what both of these pieces included made me wonder, well how would I handle my students, how much technology, how friendly should I be… etc etc…. I don’t have the right answers to all these questions even after doing the readings and thinking about the responses to these questions.

However, what I do know, is I vow to be passionate about what I teach or quit. I vow to transfer these passions to my students. I will not have any student feel like research is more important than teaching them. The students, and the print left within students will be there. I will also be there for my students, and I will encourage them and support them. I will teach my students the tools they will forever use in their lives for their success. That’s what I know. I can’t tell you if I’ll buy into a lot of technology or a mild amount, but I’ll stick to making my students the best most passionate students in the world. That’s how I see it. If you have any tools or tips to make this possible, please leave me a comment! Thanks!

On the Way of Finding My Teaching Voice

In “Finding My Teaching Voice“, Sarah Deel narrates her journey of developing her teaching style from mimicking other good professor to being herself as a teacher. She faced many questions that I also have when I am finding my own teaching style.

I have being a teaching assistant for more than 6 years and a guest lecturer for several times. My advisor and the professors I worked with think I am ready to teach a class by myself. Thus, I was offered an opportunity to be an instructor for a summer course. I used similar teaching methods like my advisor who teaches this course in spring semester for a long time. Deel gives a slightly negative attitude to using some of your previous professor’s techniques in the classroom, as if it is opposed to finding your own teaching voice. But I think it will help you develop your own teaching voice when you take advantage of  some truly exceptional techniques. I tried to attract students’ attentions with videos, discussions, and various related examples during my lecture sessions (50 min) but I didn’t do well. Many students would do other things after 20-30 min of some lectures. Students thought the lectures were not interesting. That’s my fault. I am very bad at using humor in the classroom. I always use a lot of examples to make concepts/methods interesting to me, but it doesn’t work for students. I can understand many jokes from professors but it is really hard to me to incorporate proper humor in the classroom. I don’t know how to change the situation. How to incorporate humor in the classroom? Is it necessary to be a good teacher?

Defying Gravity

How would I describe my authentic teaching self? Rough. Over compensating. Ok. I’m not real sure at this point. While I have had the honor of teaching people one-on-one, or giving presentations to my classmates, and a few experiences training/teaching new hires at former jobs, I have not had the full experience of teaching a class on my own.

I would love to say, my ideal would be transparent, inspirational, fully present, and encouraging. Transparent enough that my students would understand that there is no way I can be the end-all, know-everything, expert but experienced enough that they can take what I have to offer from that knowledge and understanding. Inspirational that would create thoughts beyond just the requirements of the class and stir a desire to find out more on their own. Fully present, that I can be enough in the room to know what is going on without being said. To be sensitive to the needs of the class and meet them where they are in that moment…be it to discuss what is on the syllabus or what may be happening in the world which could be overriding anything we could cover in class. Finally, encouraging. I would hope that as a teacher I would be supportive and a champion in helping them gain strides in their learning. To be able to have a marked difference from class day one to ending class day.

However, I started out with the words: rough, over-compensating, and ok. I use these adjectives because it is true to how I am currently. Rough because I do not have the experiences in formal teaching to have polished these skills. Over-compensating because I have a tendency to prepare, research, prepare, and repeat that cycle a bit more until I feel prepared to know the material. Usually that is to my detriment, as I learn too much and have difficulties in getting material down to the level where the students are because it all seems important and necessary to me. Lastly, I say ok. Ok, as I have done some things before and have been told I was quite good. That I have a way of explaining things to others without making them feel that my way is the only way and breaking things down into easier to understand ways.

After reviewing some of the materials on finding my teaching voice, I find that being authentic, fully present, and transparent, seem to be a common thread. Honestly, I believe that moving forward, if I give myself enough compassion with my beginner level, I have the potential to be a good teacher. Then I can continue to hone that until I become a great teacher. I know it will not happen overnight, or after one teaching experience, or one class semester. Some liken teaching to acting, with similarities being with preparation, and performance. I think I can relate to that in many ways.

So, in keeping with that theme, and following the lead from one of my favorite Broadway musicals Defying Gravity from Wicked:

Too late for second guessing
Too late to go back to sleep
It’s time to trust my instincts.
Close my eyes and leap!
 It’s time to try defying gravity.

Let’s see if I can indeed defy gravity and become a great teacher!

Teaching to the choir

Although much of the reason that I am in graduate school is for an eventual career teaching college students, I have not had many opportunities to teach courses yet. Therefore, for a teaching reflection, I will be reflecting on other opportunities I have had to speak and the one or two opportunities I have had to give a guest lecture.

For the purposes of this blog, I will consider two different experience I’ve had related to teaching: (1) in the fall, when I gave a guest lecture for my advisor in a sophomore-level dynamics course, and (2) yesterday, when I got the opportunity to preach the sermon at my church, Fieldstone UMC. There are actually a surprising amount of similarities between the two experiences. Note: my faith is very important to me, but this is a blog about teaching.

In reflecting on these two experiences, I’ve noticed some things about my teaching style.

Examples are very important to me

Examples help illustrate concepts and help us connect ideas to things we can already wrap our heads around. Maybe its the engineer in me, but I think that examples make incredibly powerful teaching tools.

In the dynamics course, I was teaching about the impulse-momentum equation

J \equiv \int_{t_1}^{t_2} Fdt = mv_2-mv_1

Which says that there’s this thing called the impulse, J, that is equal to the change in momentum. It is a useful formula for studying things like the dynamics of billiards and car accidents. To introduce the topic to my class, though, I didn’t just give them that equation, because equations are scary. I showed a video of a golf ball deforming and talked about how the impulse represents the total effect of that deformation and restoration. Therefore, we don’t have to know the details of that deformation. All we need to know is the change in velocity of the club head in order to determine the velocity that the ball.

In the sermon, I was discussing how small actions can have a profound impact, and I shared a TED talk by Drew Dudley entitled Everyday Leadership. He shares the amazing story about a time that he gave a lollipop to a girl and it utterly changed her life. Thinking about how this moment where he had so profoundly impacted somebody without even remembering it, we can see how we may all be able to impact those around us through small actions.

Examples people something tangible to hold onto when discussions become abstract.

I like to make people move

As we’ve discussed in class, lectures can get boring and people don’t have the attention span. I like to make people move around the room if possible to get the blood flowing and to help them engage.

In the dynamics course, I used a sort of think-pair-share to get the students to try to apply the knowledge in small groups and then discuss with the class in order to make sure that students were engaging with the material rather than just listening to me drone on. In a boring class talking about a derivation, I had the students try it first. Then, they would have something to go from when we talked about the material in class.

During the sermon, I was trying to encourage people to be more conscious of creating a welcoming environment. In the middle of the sermon, I asked everyone to stand up and learn the name of one other person in the room. The room was immediately filled with energy and the rest of the sermon flowed from that energy.

Getting people physically moving during a lecture helps them be involved.

It’s important to keep people engaged

Engagement is hard to describe when giving a presentation of any kind, but it is the most important thing. I think that engagement is just something you can feel. It’s in eye contact and facial expressions, but it’s really just something that you can feel.

I felt it while performing in musicals in high school. I felt it I spent my first couple years of graduate school giving presentations to prospective students and their parents. I felt it yesterday while preaching, and I felt it from some of the students when I taught the dynamics class.

I don’t yet know how to improve that engagement in the classroom. I think that is something that I’ll be working at throughout my career as a teacher.

What do you think? Do you have any fun examples to share? Do you have fun ideas to get people moving in the classroom? Do you know what it feels like when the audience is engaged? Why is it so much harder to be an engaging speaker in a classroom environment?

Is it just a “performance”?

When I was a TA for fluid mechanics, I was given the opportunity to give students weekly recitation. This 45-min class was usually divided into two parts: I will work through some example problems for that week’s topic first, and then followed by some experimental demonstrations that facilitate the students’ understanding of some concepts. This recitation was optional. And the professor stressed that I won’t get too many of them, you know, just to make me less nervous. However, when I walked into the classroom in the first week, I got more than 30 students! That was two thirds of the class! I was totally taken aback by this for a minute, and then, without choice, I proceeded with caution and finished my first class. It is amazing how teaching can get you addicted. Well, at least for me. I started to enjoy standing in front of the students and getting their attention. And inevitably, this feeling got me disappointed several weeks later, in fact, exactly the week after spring break, when some students were still in their holiday moods. I got only five students that week. I felt so depressed that I ran to the professor and asked if it was because the way I teach. Was it because I was a bad teacher? He said: “No. I don’t think so. Sometimes students got busy or they don’t feel like the need to attend a recitation this week. So you don’t need to be sad. As long as you think you are doing your best. This is like a performance. Your performance. You got prepared, go up stage and perform the teaching. No matter how many audiences you’ve got, it does not affect the way you teach. ” I was convinced. This made me feel much better and I totally bought the idea of seeing teaching as a performance. But is it really? As I learnt recently, no. It’s better if we see ourselves as facilitators for students’ learning than as teachers. Teaching should not be a one-way knowledge indoctrination, but should be an interactive process. I still appreciate the professor’s saying that helped me to rebuild my confidence, but teaching is totally not a performance. We should, from some aspects, be cautious about our gestures, voices, and postures that can affect our communication, but we should never see the teaching podiums as our stages. Teaching is not about us. Teaching is about the students.
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