Press-fit Miniature Chair

This project displays how to create a Laser-cut 3D Miniature Chair using a Press-fit design. This chair was inspired by miniature furniture for figurines, such as the one seen above holding two Smiskis. Additionally, the look/design of the chair was based on the examples of laser-cut chairs shown in class/in Example II below.

This project used a Epilog Fusion Maker 36 Laser Cutter, 1/8 inch Plywood, Fusion 360 for designing and certain tools like masking tape, glue, and pliers.

To start with the design of this chair, I took a look at different designs on laser-cut chairs and took inspiration from the process/design that was the most appropriate for this project. I went through a lot of iterations of the chair design, finding which slots should be made, how many, how the chair should balance/legs work. The final result was a chair with 5 rows of wood for the seat part, two sides and two legs.

The parameters above show the final measurements that I created based on the measurements of a Smiski, following the vision I had for the chair. The chair height would be 25.00mm therefore I split the measurements between 10mm for the legs and 15mm for the height of the back. The slots in the sides, for the back panels to fit in, took the greatest amount of trial and error for this project. The first variation resulted in the slots being too small for the panels and not letting them fit through the chair. After adjusting with kerf, I found that the width of the slots should be the ply, in this case 1/8 in, + the kerf, 0.25 mm, which ended up giving a tight, sturdy fit. Based on the shorter height of the chair, I made three back panels stretching across the chair and two for the seat. The legs I designed to also stretch between the sides of the chairs and pressing into slots on the bottom of the chair. After building the 3D model out of each component, I created a new component and laid the pieces flat and used joints to attach the pieces onto a model of the plywood. This took a while as the 'advanced arrangement' mode was not working on fusion and therefore I had to press them into the plywood manually through joints.

The image above displays the first failed iteration of the project. The pieces all came out a lot bigger than anticipated and additionally the kerf value wasn't applied correctly meaning that the back panels and seat panels did not fit in the slots of the sides. This was when I had to go in and adjust the parameters to account for the kerf and I made the width of the panels smaller, to 3.00 mm instead of the ply measurement, just to be safe that they would fit. The parameters came in very helpful for this project as it took a lot less time to adjust each piece with how large the product came out.

After adjusting the parameters and decreasing the height/width, the final chair was able to be put together using pliers to snap the pieces together as the fit was very tight and secure. I used glue and a paintbrush to be able to secure all pieces just in case. Additionally, I ended up printing two legs per slot in order to add more stability to keep the chair standing and used masking tape to glue the two legs together at an angle. This not only elevated the look at the chair but made it much more stable, as it now had four points of contact with the floor rather than two. This meant that I also widened the slots for the legs to account for double the width in the slot. I was also able to make the glue work by holding the legs together with masking tape and then un-taping when dried.

From the reading "Build from the Bottom Up" from Skylar Tibbits' Things Fall together, I utilized the 'bottom up' approach to designing as laid out and found it very helpful in the construction of this chair, especially with all the trial-and-error done with the measurements of the results. Similar to Marcelo Coelho's light stick idea, of individual components coming together and interacting with each other to form a product, I used new components for each piece of the chair and additionally relied on parameters to construct the pieces rather than a top-down approach. This allowed for an ease in redesign when I needed to change measurements and also allowed for a more proportional/symmetrical design as all corresponding sides and angles were same measurements. This was also very helpful in the design itself of the chair as I was having difficulties finding where certain slots should go however by working from the bottom up and with different components and seeing how they interact with each other it was a lot simpler to figure out.