Liquid Metal Chair

Why can't chairs also be art? What really is a chair?

I wanted to challenge the definition of a chair, by creating something that at first glance, doesn't seem like a chair at all. I designed this Liquid Metal Chair as a statement piece, with organic, flowing shapes similar to liquid metal, that allow for a more interactive way of sitting. I resin printed a smaller version of this chair to achieve the finer details within my design.

This idea was inspired by the ADHD sofa and sigilism aesthetic. The sharper points allow for storage for books or hooks for jackets and bags, while the large curved shape creates a perfect reading nook to curl up in.

Tools and Materials:

1. Resin Printer
2. Resin Wash and Cure Station
3. Resin for 3D printing
4. Chrome spray paint
5. Isopropanol
6. Sandpaper
7. Pliers
8. Paper
9. Pencil

Software:

1. Fusion 360

Protective Equipment:

1. Nitrile gloves
2. Respirator
3. Lab coat (optional)
4. Safety glasses

In order to achieve the "liquid metal" look for the chair, I first sketched out my design on paper.

All a chair really needs is a place for you to sit, so I started with a curve big enough for a person to sit comfortably. Afterwards, I drew random curves until I achieved a design I liked. I also added holes in areas where the design was rather thick, to further emphasize the organic shape.

I then sketched out more perspectives of my design on a seperate sheet of paper and shaded it to have a better understanding of what I was going to design.

Tip: Don't overthink your design! When I was stuck sketching out the chair, I closed my eyes and drew random short curves on paper, then traced out the ones I wanted to keep and designed the chair from that. There is no correct or incorrect way to draw sigilism, so do what works best for you!

While you can upload an image of your design onto Fusion 360 and trace it in the program, I decided to completely freehand the sketch in Fusion. Using the Spline tool, I drew out all the curves and holes in my design until I had a completed shape.

With the Spline tool, I was able to adjust each point of the curve I set, until I achieved a shape that was both similar to my original design, and more suitable for a chair.

Next, I used the Revolve tool to make my sketch 3D. I selected my sketch as the profile, and the axis I wanted to revolve it around. I chose to revolve my sketch at 35°, as this allowed for the chair to be wide enough so a person could sit on it comfortably without fear of falling off.

After revolving the chair, all the edges of my "organic" shape were still very sharp, so I used the Fillet tool to round the sharp edges. However, I did not fillet the spikes in my design, in order to keep to the original design.

This step takes a lot of modifying, and you may have to use the Fillet tool multiple times, rather than once for all the edges. This is because some of the curves we drew in Step 2 may be a little tight, and the radius value that will work for one edge may be too big for another. I tried to maximize the radius value for all the curves I filleted, just to ensure that the chair had a very smooth shape.

Tip: Instead of using the fillet tool multiple times, you add a fillet of a different radius for different edges in one action by selecting the plus button (Add selection set). There are also several other settings that you can play around with for fillets, and I recommend you play around with it until you find a shape you are happy with!

When I was sketching the chair, I did not measure or account for it's size, only the shape. Now that the base design is done, you must measure the size of the chair you have designed and scale it so a person can sit in it.

To measure your chair, you can either use the Inspect tool or create a sketch on a face of the design and roughly measure your design.

I measured the distance between the base of the chair and the seat, and the distance between the backrest and the front curve. It is important to ensure your chair isn't too high off the ground, otherwise people would have trouble getting on the chair. I aimed for a seat that was between 40-50 cm off the ground, and was long enough so that you could comfortably stretch your legs out while sitting on the chair, without hitting the front curve.

Fortunately, after scaling my design, I met all the requirements, but if your design is too high or too short, you can use the Timeline feature in Fusion 360 to go back and edit your original sketch from Step 2. The steps afterwards, including the revolve and fillets will still apply to your freshly edited sketch, however you may need to tweak the fillet radius a bit if you made significant changes to your curves.

My final design ended up being over 2 m tall and over 1.5 m wide. Since this chair is meant to be a statement art piece rather than an daily-use piece of furniture, the otherwise absurd size is reasonable. However, I do not have the space nor the materials to 3D print an entire chair, so I scaled it down to a 1:32 ratio for printing.

Once my design was scaled properly, I exported it as an STL file, and uploaded it to my slicer. I have is a Elegoo Jupiter 6K Resin 3D Printer, so I used ELEGOO SatelLite as my slicer. This miniature can also be printed on a filament printer, I just chose to do resin 3D printing because it offered finer details and smoother prints.

I then reformatted my design and added the supports needed to print. Once everything was ready, I exported it as a CTBEncryptedFile (.ctb) to a USB drive, and plugged that into my resin 3D printer to begin printing.

When working with resin, it is important to wear proper PPE, including gloves, safety glasses, a lab coat, and a respirator. Once my design was done printing, I placed it in my washing station, where any residual uncured resin would be washed off with IPA (isopropanol). I then placed it in my curing chamber to cure it.

The curing and washing times varies for each type of resin, and it is recommended to search up the proper settings before printing.

In between washing and curing the print, I removed the supports from my design using pliers and wet-sanded any divots or bumps left over from the supports. At this point, the chair is complete, all that is left is to give it that "liquid metal" look!

Still wearing the PPE, I then spray painted the design using chrome spray paint in a well ventilated area (or outdoors). It is important to do multiple thin layers, rather than one thick layer.

Once that is complete, let your chair dry for a couple days.

Congratulations! You have designed a liquid metal chair! I posed a little pipe cleaner man on the miniature chair for a better idea of how to sit on it.

When making a to-scale model of the chair, it is probably better to use a filament printer. I would also include wooden beams within the chair to ensure better structural stability. Once again this chair is meant to be an art piece, rather than comfortable. That being said, a couple of cushions on the chair wouldn't hurt!