CNC - Flat-Pack Chair

DESIGN OBJECTIVE: I will DESIGN and CREATE a flat-pack chair; basically a chair that can be assembled from flat parts. The chair will be designed to fit an average size adult with an height range of 5'6" to 6' and the max weight of 250 pounds. My plan is to design a chair that is not only comfortable, but ascetically pleasing.

10/2: Initial Skill & Task Analysis Plan

Here is a break down of what I think needs to be done.

  • Get Inspired by other chair designs

  • Breakdown what designs I like and what is feasible

  • Explore chair design and the ergonomics

  • Create thumbnails of possible designs

  • Further develop and explore 2-3 thumbnail designs

  • Finalize a concept design

  • Model the design in 3d

  • Flatten the design for cutting out

  • Create prototype: cut out parts and assemble - document process

  • Finalize design and make final changes - document process

  • Create final project - document process

  • Write a reflection and evaluation of the project

10/2: Flat-Pack Chair Inspiration Board

I am really excited about this project, there are a lot of cool design directions I could explore.

10/2: Flat-Pack Chair Inspiration Board ANNOTATED

10/6: Design Analysis and Reflection

I like how this deign style allows you to create flowing forms

I like the simplicity of these designs, but it would take a lot of time and resources to make this may slices.

I like the simple sides with slotted supports

I want to design a chair blending these designs.

10/9: Explored chair dimensions and ergonomics

I want to design a chair that if comfortable, but not too relaxing, for sitting short periods like at a conference room table.

Suggestions from Wood Magazine Explored chair dimensions and ergonomics

A For the occupant’s feet to rest flat on the floor with a knee angle of 90–100°, locate the seat 16–18" above the floor. If the chair will have a cushion, account for its compressed thickness in the seat height by subtracting half the cushion’s thickness.

B To allow clearance between the seat’s front edge and the occupant’s legs, make the seat 15–18" deep.

C Aim for a seat width of 16–20". Depending on the chair’s style and your preference, you can taper the seat 2–3" from front to back (1–11⁄2 " per side). A wider front provides more leg room while a narrower back allows a little more elbow room.

D For added comfort, particularly when the chair will not have a cushion, slope the seat 5–8° from front to back. This also helps keep the occupant from sliding forward. For an office or desk chair, though, it’s best to forget the slope as a flat seat facilitates leaning forward.


E To give lower-back support without interfering with the shoulders, plan for a back height of 12–16" above the seat for a casual chair and 20" (typical) for a formal chair.

F Slant the back up to 5° for a formal chair and up to 15° for a casual chair. Keep in mind, though, that as the back angle increases, you need to up the seat angle (to maintain the seat-to-back angle between 90° and 100°) to prevent forward sliding and lower the seat height to keep the front edge of the seat from contacting the back of the legs.

G To give “rear” clearance for hind parts, leave 3" of open space between the top of the seat and bottom of the lower backrest, or curve out the lower 4–8" of the backrest.

H For the armrests to support the forearms without elevating the shoulders, position them 7–9" above the seat. Be sure to check the table-apron height when determining the armrest height so the arms will slide under the apron.

I , J, and K .Make armrests a minimum of 8" long, 2" wide, and spaced approximately 19" apart.

10/9: Created a Reference Character

Used Autodesk Character designer to create a simple reference character with the height of 178 cm or 5"8".

Imported the character and posed him in Autodesk Maya. This is the position I chose.

10/10: Thumbnail sketching possible designs

I think the thumbnail sketches turned out great. There are some design I would like to explore now an others I would like to explore in the future.

10/12: Finalizing my design direction

Since this is my first chair design and it is going to be tough to predict the problems I may have to overcome. I will start off with a simple design that is both functional and aesthetically pleasing. Something like this with cross sectional supports

10/14: 3d Sketching possible designs

I like the flow if line. May explore adding the bench style seat.

I like the sharp angles. Maybe this is a future design.

Do not like it smoothed.

10/16: 3d Sketching possible designs

I like this design. Very Simple and clean lines,

I really like the flow.

10/20: 3d Sketching possible designs

I like the concept. Worried about the integrity. But the slight flex might make it more comfortable.

10/22: Playing with possible stretcher, top slats, and seat placements.

Trying to figure out the best placement of the stretchers.

10/22: Looking at possible variations of the design

Exploring if I can layer the side chair supports. Seeing how it would look and how I would make it.

10/25: Made final adjustments for body position.

Finalized Design

10/26: Performed a Boolean operation

Performed a Boolean operation to create slots for the stretchers. Also create notches for seat and back board placement.

10/28:Finalized design and flattened the design for cutting

Moved pieces around to optimize cutting.