My Adventures with 3D Printed Insoles - Part 1/4

Part 1 - Introduction

What I aim to show within the next few articles is how anyone without any qualifications, experience or knowledge in the podiatry field (that's me) can produce comfortable insoles using a completely free open source tool chain. There have been many 3D printed insoles before, certainly the more expensive multi-material printers have been showing off their exploits for a while now, however with this new democratised power of the maker movement, I would like to show and share some new found skills.

I am going to split this article into 3 further posts, each one focusing on 3 accumulative techniques that I have been experimenting with, each technique is not mutually exclusive, they can be mixed and matched with each other.

It can be assumed that I have produced all of my prints with Filaflex, the softest and most elastic material for FDM printers. If anyone wants an FDM printer recommendation for printing shoes/insoles then look no further than the Lewihe Sneaker printer, tested at 120mm/s printing of Filaflex and with a large build volume for shoes.

---

Here is a little overview of each post :

Part 1 - This Introduction
Part 2 - Open Core Mesh
Part 3 - Variable Density
Part 4 - Form Fitting

Open Core Mesh

Variable Density

The omission of the top and bottom layers of the print to expose the infill structure. This increases ventilation and can soften the feel of the print. It is also quicker to print and uses less material. Some nice infill patterns can finally take centre stage too.

With the later revisions of Slic3r and also Simplify 3D, there is now the ability to change print the properties for various discrete areas of the model to be printed. I did say this was an open source tool chain and I haven't used Simplify3D so my observations will be made using Slic3r. Slic3r can now use "Modifier Meshes" which are stl models imported onto the virtual build plate. Where these intersect your model, you can specify a whole new set of slicing parameter changes for this intersected zone. In the case of a variable density insole, it is the infill percentage that is modified.

Form Fitting

Another piece of the jigsaw, is how to create the surface of the insole to fit the form of your own foot. I will show you with the aid of my cheap 5 year old flat-bed document scanner how this surface is achieved.
It is difficult to describe in pictures just how flexible and comfortable this printed insole is.

What Next?

It's hard to say where this is going to go. There are many thousands of diabetic sufferers that have foot amputations due to ulceration, in far too many cases this is caused by ill fitting shoes and is preventable. This could provide a quick, low cost, and comfortable solution. What about a scanner and printer in every high street shoe shop or podiatrist clinic/medical centre, that would be a start.

It would be great to automate the various parts of the software tool chain into a wrapped up turnkey solution (free and open source of course), effectively to de-skill the process further. However this is outside of my individual skill set, although I am happy to collaborate further if anyone is interested.

The disclaimer here is that I am only providing information, this is not medically certified and is not designed to be such, but hey in many parts of the world, people walk round on planks of wood or old car tyres so everything is builder beware. Go forth and MAKE!!!

Read Part 2 - Open Core Mesh here.