Background: lasts
Background: parametric design
A shoe last is the most important part of a shoe as it dictates the form and therefore how it fits the foot. A shoe last is a form that has approximations and tolerances for building a shoe around. By creating custom shoes lasts through grasshopper and 3d printing the rest can be done in a Traditional way thus leveraging the best aspects of both.
parametric shoes have been done many times before but they all abandon and sense of Traditional craftsmanship or materials. By using the node-based system grasshopper geometries can be made based on scans of feet. This will be making files for use in CNC devices such as CNC mills and 3d printers.
How can traditional shoe-making embrace digital design/manufacturing techniques to produce custom orthotic shoes on a local level globally?
My answer is to make a system that can convert a 3D scan of a foot into a shoe and a shoe last.
My aim is to try and democratize shoe production to best fit the needs of more people
Traditional shoe lasts (on the left) do not conform well to the shape of the foot this can lead to feet that are permanently squished into a shape that resembles one. My project aims to make lasts to the shape of feet.
After trying many different approaches that did not work such as in the one above I sliced the lines of the foot and then lofted them to make a better last shape this did not work
The lines were very harsh but the general concept was working so I smoothed them This was very close but it did not conform to the functional requirements of a shoe last also the script was bloated and was impossible to refine. The main issue I identified was the lack of a back curve which would rub against the back of the foot and cause discomfort. There are a lot of extra wobbles that I wish to get rid of .
trying to derive and apply an accurate curve to the last from this approach got rid of a lot of the valuable info making the last almost generic. So I needed to start from scratch with a different approach
The first step in the new approach was to draw a series of points around the foot to get info from all angles of the foot. Those points are then pulled to the foot geometry and a series of lines are drawn between those lines to give a base to make a surface form The lines are then lofted to make a shell of the foot in a shape that keeps the important curves of the foot. The holes are then closed to make a last based on the 3D scan of the foot. This made a far better last shape in an easier-to-work-with data structure Meaning production will be easier.
Application of the sole scrip demonstrating how the sole can be changed in height. I also want to add more types of soles e.g. a more sporty-inspired sole as Jack suggested a simple heeled boot and other more vintage styles Fionn (personal communication, October 1st, 2023) liked the idea of edgy so more extreme shapes and unique could be used may be less practical but this will be offset by the last conforming to the foot shape properly.
The shoe sole footprint can be changed to this at this point uncontrolled but for this prototype, I will keep a thick side profile on the cup sole so the CNC drill does not break the form.
To best suit the user I modified the grasshopper script to make and edit 3 different sole archetypes that all take reference from the foot scan
After making the patterns I made three different uppers to correspond with the style of the sole
By using a desktop CNC mill I could make the soles with only minor post-processing needed. For efficiency, I made the soles out of gold foam as a stand-in material. These soles would be made out of rubber or EVA foam like what is found in sneakers
Conclusion
Due to the digital nature of the output of the script, this will be useable by most locations that have access to a computer and any digital manufacturing technology. By designing the script for the more restrictive digital manufacturing techniques such as CNC it will still be usable by the more freeform methods such as 3D printing. the result will change in response to the availability of the materials in the area. 3D printing is often thought of as cutting-edge and expensive technology that is unattainable. This is untrue as the average person can buy a 3D printer for less than 400 AUD (Creality Ender-3 V2 3D Printer 220x220x250mm, n.d.). 3D printing is also one of the easiest forms of CNC as the skill floor is very low, especially in the case of this system where the geometry is generated.
My aim is to try and democratize shoe production to best fit the needs of more people. This has the added benefit of contributing to localism as it allows the creation of a much smaller supply/production chain(Fletcher & Tham, 2019). There are unfortunately some limits to the system. the first example is that most developed cities do not have leather tanneries so this makes the supply chain much larger for just one aspect.
The second glaring limit is access to a consistent electricity connection as the technology that I am designing for can not handle a shut-off mid-way through. Despite all of the limitations the output future proof and will be as sustainable as the society it is used in. Hypothetically if a method of 3D printing had zero environmental impact the shoe could be made using this method from the output of my script.
The script takes the geometry of the user and uses it to produce all of the shapes the collaboration is inherent in
and is the base for the whole system. I also did a survey to get an idea of the aesthetic preferences of my 3 users.
and is the base for the whole system. I also did a survey to get an idea of the aesthetic preferences of my 3 users.
