Having recently built up a bike for my beloved, I was immediately taken with idea of making high-heels with a clipless cleat. I had been keen to build a pair shoes for a while and the curves of a high-heel shoe seemed like an inviting challenge.
Indeed, it was a challenge. The project spanned about 18 months, and sadly, outlived my relationship. However, don’t let this dissuade you – if I had worked straight though on the project, it would have only taken a few months, and if you can make these shoes, you are probably capable of not loosing the relationship with a wonderful girl.
Step 1: Find a benchmark
Step 2: Drawing the sole
The challenge in lofting the entire shoe is, as usual, building a nice set of guide and profile curves. I made a spine curve down the center of the shoe from the top view. I then projected that across the side profile of the top and bottom outline of the shoe. This formed outline guide curves for the front of the shoe.
Once I had the top and bottom spine curves, I created a set of planes perpendicular to these spine curves and set about making the profiles.
The final trick was to separate the forward loft from the heel and loft the heel separately.
I also recessed a section in the top surface of the sole to allow space for a leather insert. I modeled this surface as a sheet metal loft so that I could unwrap it to create the pattern for the leather insert.
The final Solidworks file is attached. This is modeled as a size 6 shoe.
Step 3: Realizing the Sole
Pre-processing: Rather than trying to get the toolpath perfect, I did a quick lofted path with a ½” ball endmill and planned on a lot of finish work. In retrospect, a more subtle approach would have been less work in the long run.
Machining: I trued up the block with a large shell mill so that when I flipped the part, I would be able to find the center again. In total, it was about 5 hours of machining (Zebra wood is incredibly dense – it would have been easier to machine aluminum). Obviously, wood is not great for machine tools, so actively cleaning as you go is a good idea.
Step 4: Finishing
For the sanding, I started with a pneumatic angle die grinder which is an amazing tool for finishing almost anything – it is lightweight and powerful. Following this, there was a lot of manual sanding. Still more sanding and ever more sanding.
Finally, when things looked reasonably smooth, I propped the shoe up on the tips of drywall screws and painted on a thin layer of epoxy. I made a mistake here and added some mico-ballons to the epoxy to increase the viscosity for filling voids in the wood. This has the undesirable effect of replacing the voids with small white dots… ugg.
After more vigorous sanding of the epoxy layer, we sprayed the shoes with a layer of Polyurethane which made them beautiful… do not skip this step.
Step 5: Design the straps
I experimented with modeling her foot from memory and creating developable lofted surfaces (sheet metal parts in Solidworks). This was useless, and since the surprise was … well, over (see step 4) … it was a lot easier to do the typical dress making approach and cut to fit.
Using some of the basic curves I had developed in Solidworks, I cut out a set of paper templates and fit them to her foot. After about 7 iterations, I found something that liked.
Step 6: Build the straps
I then attempted on a number of occasions to sew the straps. After failing on all attempts, I capitulated and hired a friend who is a pro, Bree Hylkema, to finish the straps. She did a wonderful job. Sorry, I don’t have any pictures of this – imagine a very skilled woman sewing with intimidating precision.
In finishing the straps, Bree added some stiff canvas into the center of the layers of leather to prevent the leather from stretching.
Step 7: Final assembly
Some of the leather for the sole had been misshapen during the sewing process. I found it easy to bring it back into shape with an iron and a light misting of water.