Interview with Christopher Cho, Senior Application Engineer, nTopology

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Christopher Cho is a mechanical engineer with a background in additive manufacturing and mechanical design.  He is currently with nTopology helping customers push the envelope with the next generation of medical device and manufacturing applications.  He will be giving a workshop during 3DHEALS2020.

Jenny: What were you thinking when you first encounter 3D printing? What were some of the earliest projects you did with 3D printing? 

Christopher: To be honest, my first project with 3D printing was making a prop for a friend who was going to cosplay at a convention.  I looked at all the traditional manufacturing methods that required a lot of manual labor and artistic eye to make these complex and custom shapes.  If you didn’t have the cash to CNC something, you had to really break out that elbow grease and mold and form and cut things down to the shape that you wanted.

But with 3D printing, it was like the lazy way out.  If you were proficient in CAD, it was much more easy to digitally mold the geometry you wanted rather than actually mold it yourself.  But then again, I’m not an actual artist, so there’s probably going to be a lot of people that disagree with me on that.

But yeah, it was like doors just opened up once I got a 3D printer.  I could “make anything”.  That was the dream they dangled in front of me, and I bit.

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Varying surface morphologies achievable with nTopology Element.

Jenny: Who or what inspired you the most along this journey in 3D printing?  

Christopher: I think what touched me the most emotionally in recent years was the prosthetics side of this.  I was at AMUG I think a few years back where I met an individual who was using cheaper 3D printed materials to run prosthetics for under-served communities in Latin America.

And at his talk, he played a short video of him there, scanning people, printing prototypes and test-fits, and ultimately printing the fitted prosthetic component itself and you would see these individuals, amputees, who previously could not walk, and they now could.

It wasn’t crazy high-end technology that required extreme skill or resources where that support would just evaporate the moment he was no longer there.  It was a functionality that was actually accessible to the local community.  

You know, you give someone a leg, it’s a leg.  We take walking for granted because we do it all our lives and don’t give it a second thought, and here in that video, I saw people just overjoyed that they could just do it again.  Yeah that kinda hit me a bit.

Jenny: If you can go back 5 or 10 years, what would you have done differently? 

Christopher: If I could go back 5 or 10 years, I would have doubled down on the manufacturing and development side of my education.  I was thinking I would stay in New York City my entire life and the only real consistent mechanical engineering work was in HVAC (Heating, ventilation, and air conditioning), so a lot of my educational focus and the graduate study were around that sector.  

I think I would have had a lot more fun if I dove a little bit earlier into stuff like supply chain, control systems – that kind of thing.

Jenny: Software, materials, or 3D printers. It has been an ongoing debate in the industry forever as to which is the most important player. What do you think is the most important player in healthcare 3D printing? 

Christopher: From a 3D printer or hardware perspective, we can look at the manufacturing technology today as being in a state where anything you can imagine can be manifested within a bed of powder.  Regardless of complexity, internal geometry, tooling, fixturing, and other bottlenecks that existed in an age where subtractive was at the pervasive forefront, the additive can essentially create any steady-state shape that we can imagine in three dimensions.  From there, it’s just a matter of scale.

Software is also riding this massive movement where in the past, a piece of code was an extension of a human being where tasks and productivity could be made infinitely more efficient.   With the onset of machine learning/AI, we’ve essentially taught machines to no longer just DO for us, but make smart or potentially smarter decisions for us as well.   

Materials on the other hand, are kind of an interesting beast.  We’re bound by the periodic table and its combinations, where a good portion of it doesn’t even get used.  We’ve had access to strong materials for thousands of years, since the Iron Age, but we’re using what are essentially the same materials today.  In cars, planes, and implantable components, just a bit more refined.  On top of that, unlike the other two, it’s primary function is to be consumed; a finite resource.  We technically only have so much of it, and it has and will define humanity is where we go and how we adapt and survive.

So from my point of view, I would honestly consider the materials to be the most important player, because it’s what will probably limit us the soonest.  We’ve developed it the least over the longest amount of time and we’ll technically always be running out of it.  So I think we’ve got to focus on it the most.

Bringing the scope of it back to healthcare, the conversation of biocompatibility only further limits our options, definitely doesn’t expand it.  So that only emphasizes that point more.

Jenny: Can you share how nTopology differentiates itself from other companies that also produces 3D printing design software? 

Christopher: nTopology is really just an amazing piece of software.  

CAD software is kind of a dime a dozen.  New packages come out from new vendors, and the UI is improved and it’s easier to visually use, or its cheaper and more accessible.  Or maybe it’s got automatic cloud syncing so you can take your files anywhere and everywhere.  But at the end of the day, it’s still CAD.  None of it improves upon the modeling capability at its core; it all still works the same way under the hood.  

CAD was a technology that was developed to imitate drafting.  You made this 3D model so you didn’t have to pull out your 0.9 lead pencil and redraw new orthographic views of it every time something changed.  

nTopology basically scrapped the whole traditional modelling process entirely and went with implicit modeling.  It’s a volumetric approach that doesn’t suffer from explosive regeneration errors simply because a fillet operation from 30 steps ago no longer applies.  The geometry just doesn’t work that way, and you can vary different parameters in unique ways using gradients, or field-driven design, as we call it.

But the biggest thing for me, is the amount of time saved when I use it.  The design methodology used is workflow-driven, not just output driven.  So geometry that we create essentially has a complete ‘paper-trail’ that can be reapplied and reused over and over again.  So if you’re trying to put a randomized lattice on something, like a spinal cage, it may take a bit longer to develop the workflow the first time around; however, applying that same workflow to a sister part within that part family where only the angle or width of that spinal cage was slightly changed – a massive amount of time is saved.

Here’s how: by just changing the model that your workflow is being applied to. There’s no process of redefining your parameters for this slightly different shape or stepping through those manual motions all over again.  The workflow is there, and you can just start pouring models into it.  And I use the word pouring because it’s fast.  Like, really fast.  Sometimes seconds fast.

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Jenny: How is COVID19 impacting your life and work? 

Christopher: COVID has been a tough time for everybody, and I’ve been extremely lucky to not have been impacted significantly by it.  I’m grateful to still be working and working remotely.  Working remotely is not a foreign concept to me, so I could honestly probably do this forever.  But there are a lot of people out there who have been impacted significantly and I have nothing but appreciation for our healthcare workers, point-of-care workers, and essential workers who have done nothing but keep our society afloat these past few months.  So really, hats off to them and I hope they get more than just thoughts and prayers coming out of this.

But it’s definitely changed my life and everybody’s life in such a drastic way especially when it comes to social interaction.  There are just new expectations and new standards that everyone suddenly had to conform to, and it would be interesting to see how much of these changes have staying power as the rest of us kind of re-emerge from our caves.

Jenny: What good advice would you give to a smart driven student to succeed in the “real world”? What bad advice they should ignore? 

Christopher: The best advice I can give to a current student is to stay inquisitive, stay curious.  You know, keep asking questions.  A huge percentage of workers out there are not in the field that they studied to be in, so there’s no need to feel married to a specific industry.  

I try to be a bit more candid when it comes to those students who are deciding what they want to do in life or are just entering the workforce.  I would recommend finding out if the job they’re aiming for is actually the job they want to do.  I became a mechanical engineer because I wanted to make and design cool stuff, but no one ever told me that I would be spending 4 months revising a sheet metal box over and over again because requirements kept changing.

So yeah, understand the job, talk to people, and understand the business.  There’s politics in the workplace and understanding how to navigate that kind of thing is better done sooner than later.

Jenny: What was the best investment you made in 3D printing? 

Christopher: The best investment would definitely be in me.  It’s not always about getting new machines with cooler features or fancier materials.   The technology is fickle.  It doesn’t always work and even today, the scrap rate on additive parts is insanely high.  The best thing to do is to learn how it works at a really technical level as best as you can.  If possible, take a machine apart, put it together again.  Get familiar with the software, and the firmware if possible.  What does a specific slicing parameter do and how does it actually impact your part?  Something that seems trivial at first may cause you hell down the line in QC or inspection.

You gotta invest in yourself first and learn everything you can.  Knowledge is always scalable and extensible, even if it doesn’t immediately appear so.

Jenny: What was the biggest risk you took in your career? What was your thought process to overcome your fear? 

Christopher: My biggest risk was jumping into additive.  I was 16 months in on a contract with a huge component manufacturer that served AeroDef and other large industries.  It was my first real job out of college and I was just glad I had employment straight out of school.  

But after a while, the pace of a company that was that large just kind of took a toll on me.  Every day felt the same, I wasn’t really doing anything new, and there was so much downtime waiting for signoffs and charging this program and not other programs; you know, a lot of bureaucratic stuff.  

While I was working there, I bought my first extrusion 3D printer and had been playing with it.  I saw a job in the city and it was a significant downgrade to an internship role at basically minimum wage with no guarantee of anything beyond that.  But, it was 3D printing and that was something that really excited me.  So I dropped everything and pulled the trigger.  I did odd jobs here and there and used my personal printer to help pay rent and barely skated by.  But it was the first of many steps that brought me to where I am today, and I am definitely much happier because of it.

Jenny: What is your favorite quote? Why? You can also give us your own quote. 

Christopher: I’m a big fan of:

“You made the best decision you could with the information you had at the time.”

I’m not sure who said that one, but it means a lot to me because it allows me to look behind me and not regret the decisions I’ve made, and it also forces me to be more informed and more prepared for the decisions I will have to make in the future.  

If time travel comes to be in my lifetime, my answer to this question will probably change.

Jenny: What does the word “3DHEALS” mean to you?  =)

Christopher: I think 3D Heals is an interesting name.  It can be interpreted in a lot of different ways, but I like it read it as a proclamation.  “3D Heals!”  

3D technology, both digital and physical is something that can be used to heal.  And that’s absolutely very true.  Higher quality implants, more form-fitting prosthetics, more accurate surgical guides… I’m definitely missing so much from this list, but just better patient outcomes in general, all empowered because of this ever-growing wave of 3D technology.

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