The "Tinfoil Asteroid" Motor Enclosure

This Instructable will give you an inside look at a central feature of an elaborate ongoing vehicle transformation entitled "Love, Inertia, and the Pursuit of the Perfect Stance."

During my time as an artist-in-residence in the Pier 9 Workshop, I used their incredible digital fabrication machines, 3D scanning, various types of Autodesk software, and traditional metalworking processes to create a unique "low polygon, stealth fighter jet looking, ball of crumpled tinfoil asteroid" motor enclosure. The artifact houses a modern turbo diesel motor and transmission. Follow along to see how it was done.

...But first, some backstory on the project:

In 2005 I began creating a series of unique interactive vehicles that fuse a fascination for sculptural objects, furniture design, and the subcultures revolving around custom automobiles. These works exist primarily in a gallery context, occasionally getting an opportunity to put rubber to road and "play" outside.

I wanted to go bigger and test these concepts in the "real world" outside the bubble that museum spaces provide.

In 2008, I started with an idea to acquire and heavily reengineer a 1963 Ford Falcon Deluxe Club Wagon (a Ford Econoline van with all the extras) into a truly unique "tour-de-force" vehicle sculpture that aims to connect this surviving artifact of idealistic Americana with the elements of the contemporary "customize everything" culture.

This piece, entitled "Love, Inertia, and the Pursuit of the Perfect Stance", will be the grand finale of my vehicle series (maybe).

The Motor Enclosure:

As with any body, there is not a lot of room for a lot of differing functions to coexist.

Building from the doorsills in, piece by piece, I've created an all new sheet metal floor covering the raised wheels and tube frame.

The motor and drivetrain (a turbo diesel engine from a Volkswagen mated to a Toyota truck transmission) are located directly between the front wheels and the driver and passenger seat. It's the heart of the beast.

The motor enclosure is the primary focal point when looking in through any of the thirteen windows of the van.

The goal was to isolate the cabin from moving parts, heat and noise, create visual interest, and to interface all smoothly with an asymmetrical form created to flow around the motor's form.

The notes in the photos will give you more information. Enjoy.

Step 1: Mock-up, Scan, Design, and 3D Model

First things first. I defined the edges of the enclosure, then began to mock it up in space with good old-fashioned rulers, tape, sticks, and clamps to make sure this design approach was going to work visually. I wanted to sacrifice as little interior space as possible while allowing enough room around the motor as to not cause problems. The motor needs room to move a bit when under load and elements such as the turbo and exhaust downpipe let off large amounts of heat. Adequate airspace is key.

When I determined these edges and reference points, I took a 3D scan of the motor and surrounding areas using 123D Catch. This program takes a series of photos and creates a fairly accurate STL file that can be inserted into 3D CAD software. This was done with a Canon G15. To simplify the model and bring down the file size I covered the motor and transmission with a drop cloth and marked with green tape the key protrusions to be mindful of. See Video.

I then imported this file into Autodesk's Meshmixer to clean it up, trim excess information, and generally tidy the file, then over to Meshlab to lower the resolution (polygon count). I could then import the motor scan into an existing 3D model of the floor I had built previously. From there I designed the motor enclosure with vectors, then created planes and a solid form that worked visually and within my design requirements. I brought that solid form in to 123D Make to located the seams and get a flat pattern for the Waterjet. 123D Make will give you an option to include a perforated line where the bends take place. This can be helpful, although I opted for doing it "by hand" in layout software so that I could get really specific and minimize my welding and metalwork time. It was then time to put the screens away and get these hands dirty.

Step 2: Cut Parts, Prep Metal, Bend, Tack, and Fit.

I cut the motor enclosure from a 4' x 10' sheet of 18 gauge cold rolled mild steel. (I considered using stainless as later it would not need paint, but I decided against it because stainless can easily warp and move with the heat from welding.) Once the 6 sections were cut, I cleaned off the rust with a quick once over with 220 grit on a random orbital sander.

Then I began to carefully bend the panels according to the angle measurements in my 3D file. It was a pretty satisfying and straightforward process, although I was surprised by how much 1 degree variance could alter the form as a whole. Once a section was complete I could tack it in place and move on to the next ensuring that the seams were tight enough to not let light pass through. As the form came together I could start manipulating it as a whole body.

Step 3: Radiator Cover and Wheel Arch Extensions

These parts were created simultaneously to the motor enclosure but for the sake of clarity the photos are in a separate step.

The front of the motor enclosure contains the radiator, fans, and intercooler for the turbo intake. I wanted this area to be simple and clean looking while serving the function of flowing air off the ground up towards the radiator. The simplest solution is to continue the radius defined by the wheel arches in one simple gesture. To make these parts I cut out my pattern on the waterjet. After cleaning off the rust with 220 grit I sent the steel through the roller to get the right arc (first try!). Next I bent up flanges on a sheet metal brake, making sure to line up the edges nice and tight as this would define how the curve sits with the fenders. This panel will be secured with hardware enabling me to remove it to access the radiator and plumbing at a later date.

The same process was done with the 5 inch wide wheel arch extensions. I used a cardboard template to make sure they came out right. Once fit to the vehicle, they were then tack welded in place.

Step 4: Floor Build Out, Scribe, Fit and Finish.

Next I needed to build up the floor support so that the enclosure had secure places to attach. I did this with some 1" square tube and a few sections of 1/4" flat bar to span a tight section over the transmission. I then drew out the main floor panel on a fresh piece of 18g and cut it out with a zip disc (cut off wheel) on an angle grinder.

The motor enclosure was then carefully scribed to fit around the wheel arches. Slowly but surely it got better and better. Once I was happy with the fit I mounted the enclosure with quick release fasteners called Dzus Fittings.

Eventually I'll finish of the metalwork on the motor enclosure when the rest of the vehicle is ready for finishing details. Now, it's time to move onto the seats...

Step 5: More Information & Thank You

I'll be adding more content and links to this Instructable over the next couple weeks. For more information about the project "Love, Inertia, and the Pursuit of the Perfect Stance" go to my website or find me on Instagram where I post about this project often.

Thanks for your eyes.

- Shawn HibmaCronan

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Shawn HibmaCronan creates large-scale, moving sculpture from wood, steel, and reclaimed objects intended to engage the viewer, activate an environment, and spark conversation. Embracing traditional and contemporary methods of making, Craftsmanship is critical in his work. No material is disguised and no mechanism is hidden; the resulting forms are honest, tangible, and iconic.

HibmaCronan's work has been featured on ABC7 News, SFist.com, Woodwork magazine, Multilingual magazine, Glance magazine, and Craftzine. A speaker at the 24th Annual Creative Summit Design Conference in San Marcos Texas, he has shown work in multiple group shows at venues including the California Shakespeare Theater, and exhibited his work in a solo show with the Oakland Museum of California. He has received multiple public and private commissions including large site-specific works. He was recently commissioned to create a sculpture entitled "Freedom Press" for permanent exhibition in the San Francisco International Airport. In November of 2013, HibmaCronan was an artist in residence for a show called "Out of Hand/Hands On" at the Museum of Art and Design (MAD) in New York City. He is currently an artist in residence at Autodesk's Pier 9 Workshop in San Francisco and completing a thoroughly re-engineered "street-legal sculpture" vehicle made possible by funding from Kickstarter.