18 Jul, 2019

On CATIA For Fabrication With Neil Meredith

I had the opportunity to interview Neil Meredith, a former colleague from Gehry Technologies, (now Trimble Technologies). Neil currently works at one of the most advanced fabricators in the US, MG McGrath. My goal from the interview was to shed some light on how they use CATIA in practice. Let's get to it!

What do you do at MGM?

MG McGrath is a fabricator and installer of architectural surfaces. The company is headquartered in Minneapolis within a 100,000 square foot facility, but we have projects and field crews all over the US. Typically we develop unitized building enclosures out of metal or glass, but we have a lot of flexibility and work on multiple scales and project types. We also work in other materials like GFRC, stone, etc. depending on the project. I’m based out of New York City where we have a small field office.

I am an architect by training but have been working in the overlap of construction, fabrication and technology most of my career. I tend to gravitate towards complex projects because that’s where a 3D model-based approach can have the most immediate impact. The complexity can look like geometric complexity (like the BAM/PFA project), scalar complexity (so just large projects with lots of parts to manage like in the US Olympic Museum), or just the typical detail level complexity of something like a unitized curtain wall.

I work in our Virtual Design & Construction (VDC) group and my role here is to help make McGrath the most technically advanced fabricator in the AEC industry.

We were colleagues at Gehry Technologies, probably at different times. More than a decade later, what impact do you see GT has managed to make on AEC?

We were there roughly the same time, but we worked on different continents! When I first started at Gehry Technologies in 2007, the role of technology in architecture and construction wasn’t really mapped out yet. By working as a consultant and trying to figure out how to get these complex projects built, I had exposure to a bunch of different practices and ways of working. One day we would be working with Diller Scofidio + Renfro, then the next at Robert AM Stern. The projects could not have looked any more different, but the approach and what we were trying to accomplish was the same. So that was exciting as an architect, to get exposure to the thousands of decisions that happen after the Construction Documents go out the door. It seemed like under explored territory.

One thing GT got right was to just get a bunch of smart people in a room and give them the tools to do the best work they can do. Like any start-up it had the feeling of working in a pop-corn popper, but the people involved in a lot of this early work have gone on to do some really compelling things, at different types of companies, all over the globe.

What is the journey of an engineering solution at your company? Where does it start and what tools take the lion share of your process?

When developing a system design, we always start with the architect’s concept. Understanding the design intent and capturing the look and performance of that system is really the guiding concept. Once that is established though, the detailing and development can go in wildly different directions.

One direction is physical mock-ups. We learn more and get answers quicker when we build real things in the actual materials. For that we work closely with the shop to quickly produce physical prototypes and mock-ups. These mock-ups also acts as a check out of our modeling process.

By prototyping things as we go, we can verify the design-to-fabrication process with the people actually doing the assembly. This saves us from having to automate a lot of dumb information in the first place. If the shop can build something more effectively with a single diagram and a spreadsheet (as opposed to thousands of unique part drawings) we can integrate the work packages to be as lean as possible while still giving everyone the information they need for their part of the project.

On the modeling side, we use the 3DEXPERIENCE platform to capture all the model geometry and output all the fabrication parts and pieces. We use the same platform for design review, as well as as-built field points so we can make any adjustments prior to heading to fabrication. To make these changes and maintain updates across all the parts, we use the parametric core of CATIA to keep all this geometry in sync.

How much of your project delivery relies on digital mock-up, reviews, and issue tracking? Or do you rely on 2D work-flows?

Once the model is established as the medium of communication, we can then iterate on all the connections and details. This is not a top-down process either, but balances input from engineering, the design team, constructability from the field, other consultants, etc. Once all the project stakeholders have signed-off on the completed mock-up and details, the same process then begins, extending now to work out all the conditions in the rest of the building.

The process of drawing never really goes away with this model-based approach, it just needs to work differently. Our ideal deliverable for a design review is a fully coordinated 3D model, showing all the parts and connections in context. But we also need to deliver enough 2D details to coordinate things like stiffener types and sealant colors that don’t make sense to model. The important distinction is that we don’t want to carry any setout or dimensional control information in the 2D drawings.

How much of your work depends on automation, templates, and case to case modeling?

We automate as much as we can. To give one example, on the US Olympic Museum we have over 9,000 unique break-formed metal panels. To create these panels we use 3DX Engineering Templates to create all the geometric variations from only seven seed templates. Within the sheet metal parts, we also use a lot of EKL code in the form of Actions, Rules, and Knowledge Patterns to manage all the flexibility of the system, while still maintaining all the engineering requirements. Lastly, we use some in-house C# applications to automate 2D CAD file set-ups for our laser cutting and CNC bending equipment. All these parts are tracked using bar-codes with an in-house web application built to track panels and manage the QA process across the shop and field.

If you were to advise new designers and engineers interested automation? What kind of skills, internships, and courses would you advise them to acquire?

The biggest challenge facing the industry now is how to apply the approach we’ve been using on these complex or boutique projects to the construction industry at-large. Parametrically patterning another façade is not going to solve bigger problems like the cost of housing or the environmental performance of the built environment. The longer I’ve been in the AEC industry, the more I’m convinced that the solutions to these problems are going to come from outside our industry. I think you are starting to see that play-out now with the increase in outside investment and “disruptive” startups entering what has historically been a conservative and risk-averse building culture. I’m sure that is what’s exciting to people coming out of school now anyways.

To that end, I really don’t believe there is really one “way.” I think having a firm grasp on geometry an ability to work through problems visually are key. If I was coming out of school now, I would probably do a web development boot camp.

There isn’t really one language or software platform that does everything, so learning general programming concepts is probably more important than which language you learn. Then just make stuff; you’ll learn more by doing. Having a community (like this website!) is great for when you get stuck, so knowing some other people is the only way to really learn.

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About : Maher Elkhaldi

Maher Elkhaldi is a senior applications engineer at Tesla Motors. He founded the 3DXAutomation blog to help make knowledge of programming CATIA easier to find, and contribute to the open-source community.

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