Designing a man’s heel.
How do you start to design something that does not currently exist? It was a difficult start for us here at Cross Sword, we wanted to bring a brand new and daring concept to the market. That meant that we would need to push ourselves and make a mark for ourselves.
After many different ideas, we finally settled on a design that was similar to what we currently have on our shoes now. We set ourselves the brief of creating a heel that fulfilled functional and aesthetic aspects but also would help us to build our name as a brand.
Women's heel: left, Man's heel: right
The first challenge was to create a heel that was wider than what already existed. Current heels are a lot smaller as they have been designed to fit a female’s shoe. This posed a problem for us, as although thinner heels look nicer they are not as strong as what we would need. Men have wider heels and typically weigh a lot more than women so it was clear from the beginning that our heels would have to be bigger and stronger. This however, posed a new problem. How would we still keep our heel looking elegant and not too bulky? How we solved this problem will be explained shortly!
3D Computer Aided Design of the initial heel
Designing the heel started as with all of our designs on paper, but then progressed to using computer-aided design to produce a 3D rendering of the heel. This gave us a good idea of how it would look and allowed us to review the proportions. We could easily change the colour and the surface details to see what different materials would look like.
Plaster 3D printed heel
From the CAD drawing we were able to print a model using a 3D printer. This was a quick and easy way of having the product directly in front of us. It was printed using a printing process that solidifies layers of powder building it up step by step. Having the model in our hands we were able to see where the initial errors were and what we wanted to change. Back to the 3D drawing and another few printouts. We continued this process until we were happy with the final outcome.
Before and after the 3D printed part was polished
The design features a cut out area where we wanted to display our symbolic crossed swords. The initial idea was to encapsulate them into an acrylic piece. The swords would then be painted with a special metallic paint that reflects like a mirror. For the prototype of this piece we couldn’t use the same 3D printing process so we had to find an alternative. We used a process called SLA printing which printed our clear piece in a clear material. After a lot of hand polishing we finally had a piece that looked like we had planned. We took the final piece and made a mould of it, which we then made duplicated by casting polyester resin into the mould.
The SLA Print direct from the printer
Left:the polished print out, right: the milled heel with the printed insert
With the two heel parts printed, polished and painted we got a really good idea of what the heel would look like. Although there was one problem, the heel was not strong enough to actually walk on as it was made of powder. It was only ever designed to be used to display the proportions. With this in mind the next stage was to have a number of heels manufactured by milling out our design on a 5-axis milling machine using ABS as a material. We then took this material and added the clear insert to see what the shoes felt like when they were placed on the shoe. Adding the ABS milled prototype meant that we could try on the shoe and walk in it for the first time.
Walking in our new heel led us to conclude a number of changes needed to be made. It was a really significant stage in the whole process. Designing something brand new was never going to be quick and easy. Our next stage was to find a mould maker that could produce the moulds for our heels. In total we needed three moulds. One for the main heel, one for the acrylic piece and one for the heel tip at the bottom which is made using a special insert moulding process. We found a mould company that said they could do what we needed them to but unfortunately after a year of working on the project together the company could not deliver what we wanted. What to do next?!
We spent a long time looking around for a company that we could work with. The first company had already cost us so much time, which we were keen to make up for. It became apparent that once we started working with the new company that there would need to be some design changes. We decided to go back to the drawing board. We would need to make new moulds for the project but this time we would not be able to afford more huge delays. We turned to the moulding company for advice and thanks to their advice and the excellent work of our new 3D designer Tilman we came up with a solution.
One of the major issues with the first design was that the acrylic piece was too thick. Its dimensions far exceeded what is possible with the material which led to lots of sink marks and undefined edges in the original design. We had to scrap that idea completely but luckily we came up with a plan B. Plan B ended up being far superior to our plan A, but hindsight is a wonderful thing. Instead of imprinting the sword into the acrylic and painting the indent we decided to turn the thick acrylic block into a thin acrylic window.
100 pieces of silver
Turning the piece into a window meant that we could display the swords in a different way. We had the idea to turn to a jeweller. So we researched British Jewellers and found a great company that would take our project on. The new idea was to cast sterling silver swords and adhere them to the ABS part of the heel. We would then adhere the window to the heel. The end result would be a sort of display cabinet for the precious metal.
The next issue was how to make the piece lighter. We were advised to hollow the heel out as much as possible. Our Designer had the challenge of creating a heel that would be strong enough to hold the screws that attach it to the shoe as well as be light. Not an easy challenge and after many prototypes we came up with the current solution.
Left:new heels with silver insert, right: old heels without insert
Our 3D designer made the changes and the new company got to work straight away on the moulds. They gave us regular updates on how it was going, at the same time we were getting moulds made for the silver swords so that they could be batch produced as well. After a few months of waiting we finally had a delivery of parts.
It was super exciting getting the prototypes sent through, they were assembled and assessed. There were a few small changes that needed to happen which took a few more weeks but we were pretty much ready to go. One hundred pieces of each part were ordered, delivered and assembled but only after extensive consultation with an adhesive company. The shoes were finally ready to have their heels placed on them. We went from a three-mould-heel to a four-mould-heel but we couldn’t be happier with the end result. We are not entirely certain, but we don’t know of any other company that have precious metal as a standard feature on their heels.
From the time that the first pencil drew the first sketch until the first parts were delivered took nearly three years. But we are confident it was worth the wait.