Shoe lasts from scratch

From the Renaissance artist Michelangelo it is said that he only took away the superfluous marble in creating his world-famous David, so that the statue could come to light. He already saw the shape of the sculpture in his mind’s eye when only a marble block was standing in front of him. That is my thought when Franz Fischer puts a wooden log in my hand that is supposed to turn into a last according to my foot measures.

I know that the last is hidden in the log, but unfortunately I don’t see it yet. Is my mind’s eye blind? Or is that quite normal if you are grinding a last from the full piece of wood for the first time?

1. Step: Measuring
Step by step we will approach our last, Franz Fischer explains. Fischer ist Master Pedorthist, runs his own workshop in Amberg, Germany, but also teaches at the school for pedorthists and has founded an association to support students during their education. For the next two days I will be his student. The first step is related to my own feet. Fischer explains that often the foot exam is forgotten, but for example the mobility in the upper ankle joint is often vital for the further work. If it is limited, it has to be taken into account already from the beginning for the last’s position and the sole construction further on.
Even if my joints are not so young any more, there is no restriction of the mobility, so that we can proceed to the blueprint. Here not only the static load of my foot can be seen, but it also serves as a basis for the sole shape of the last. I place my foot on the blue print box and stand up slowly from the measuring chair, while Franz Fischer is fixing my foot with his hands, so that it does not get out of place. Then the outline of my foot is redrawn with a pen. Even pressure, so that the line also copies on the paper below, and first of all a constant position of the pen are important for the further work. Franz Fischer is careful that the pen is always vertical. Only this way he ensures that the drawn distance to the foot rim is always the same one.
Since foot and last are three-dimensional bodies, the measures for the sole outline are not enough. The ball measure is taken with a tape measure (girth of foot in the line between the outer and the inner ball), the instep measure (girth of foot at the back of the foot) and the heel measure (girth from the heel over the foot bend). Also the girth of the calf is taken above the ankle joint. These measures are written down on the blueprint.
In addition, Franz Fischer makes a plaster cast of my feet, the plaster bandage in fact being made of plastic and bound without prior wetting and then hardening. We will need the cast later as a reference while grinding the foot shape.

2. Step: Drawing of foot and leg position
If we grind the last from the full log, we need an orientation concerning the foot’s position and shape, Franz Fischer explains. That is why we draw the contour of the foot in the frontal plane from the heel via the ankle joint to the lower leg with a pen on paper. Fischer made a special device for that from wood with a ground board, on which I stand, and a board standing vertically on it, where we fix the paper. With these contour drawings we can check again and again during manufacturing if we are indeed realizing the vertical built of the last. We do the same for the contour of the foot in the sagittal plane that serves as orientation how far we have to grind down.

3. Step: Designing of the sole shape
In the next step we make a photocopy of the blueprint where we draw the sole construction. We draw the heel center, the joint line between the second and the third metatarsal head, the metatarsophalangeal joint (inner ball) as well as the little toe joint (outer ball). Those are our points of orientation for the sole shape and for the ball line that we will transfer to the last later on. First we draw a line from the heel center through the markings on the metatarsal heads until beyond the toes. Then we connect the inner ball and the outer ball with a line as well as the inner ball with the little toe. Then we determine the toe allowance for the last that will give my foot the necessary space later on when walking. We draw the line two centimeters above the longest toe in the right angle to the heel line. The position of the next two lines depends on the desired shape of the shoe. In case of a natural shape, providing full free space for the toes in the forefoot, we would take care not to touch the toes with the line from the outer and inner balls to the line with the toe allowance. I decide on a more pointed, fashionable shape. For that we truncate the big and the little toe slightly with our lines and thus receive the crucial points for the sole outline of our last.
The sole outline is drawn freely by hand. For the foot contour we orient ourselves by the contour of the blueprint, but we put the sole outline approx. 3 mm towards the interior, in order to compensate the volume of the pen with which the foot outline was drawn. At the top the line around the marker points is slightly rounded. Then we cut this sole outline. This way we receive a model that we can transfer to the last.

4. Step: Grinding the shape of the sole
After all these preliminary works, we finally come to the log of wood. We draw the sole shape with the help of our model on its bottom side, before Franz Fischer starts his band saw. We cut everything off that we do not need any more later on with sufficient safety margin to the sole shape, so that we do not have to remove all of this wood with the grinding line.
In the first step we grind along the sole contour at the bottom of the last an approx. two centimeter wide strip in the right angle upwards. The last will be built on this outline.
The classic wood for a shoe last is beech. Franz Fischer however chose poplar for our experiment. It is softer and easier to grind as the harder beech, he explains.
He grinds the first last easily, turns it elegantly with his hands along the grinding line and cuts the sole outline in no time. It does not look so easy when I do it. Also poplar is quite heavy with this volume. I press the wood that is supposed to turn into a last tightly against the grinding line and feel a pull in my upper arm after only a short time. To hold the log of wood in a stable position while the coarse grinding line mills away the wood gets to my biceps. After a short while I get the idea to use not only my arms, but my whole body in order to put pressure on the wood. “Scorch marks” on the wood show that I occasionally must have used to much pressure on the grinding machine.

5. Step: Grinding the lift of the last
Technically the next step is easier, but it requires more intermediate checking of the grinding result, because we grind the later lift of the last. Two little cork discs are our measure for the correct position. If they are beneath the heel, the back of the last has to be exactly vertical, otherwise the foot position later on is not correct. For a later slight anti-supination position of the last, we place a plastic wedge on the outside beneath the ball line and grind away at this spot so much material, that the top of the plastic wedge fits underneath and the last is even in the frontal plane. The toe lift is ground according to visual judgment, not too much but also not too little, so that the gait will be supported optimally later on.
Before we continue, the left and the right last are compared to each other. Both need to have the exact same heel and toe lift, otherwise we get two different shoes.

6. Step: Grinding the foot contours
For the first time we now use the position drawings made at the beginning. We transfer the outline of the frontal plane to the back of the last. It is easy to see that a lot of grinding has to be done until the last corresponds to my foot shape. First the contour is milled only coarsely, taking care that the lateral and the medial malleolus are not leveled out.
Only when medially and laterally the contours correspond to the foot, we also transfer the position drawing of the sagittal plane to the last. After another load of abrasive dust disappearing in the machine the last begins to resemble my foot, even if it is still quite angular.

7. Step: Molding of the last sole
This will change in the next steps. First we grind the foot sole outline very precisely according to the line on the blueprint. Then we begin to model the foot sole sculpture at the heel. The heel is rounded and adjusted to the foot shape. We grind the longitudinal arch until the ball line and we also grind a soft bow on the outside until the outer balls. We have determined the ball line before with the help of the blueprint. For that we put the last on the blueprint and transferred the marked points onto the last. Then we drew the curved ball line, also marked on the blueprint, along the metatarsal heads freely by hand onto the last.
The biggest difficulty for me with the foot sole sculpture are the shapes of the pelottes. Their position has been drawn behind the ball line, but how can I achieve the elegant, soft drop shape of a pelotte with the flat grinding line? Carefully I put the last sole against the grinding line, so that I avoid grinding a gouge instead of a pelotte at my first attempt. By turning the last and careful up- and down movements on the edge of the grinding line I succeed to grind something like a three-dimensional shape without hard edges in the last sole. But only after Franz Fischer turned the last sole several times over the grinding line it looks like a pelotte.

8. Step: Modeling the forefoot
Finally it is time to approach the log of wood to the shape of my foot. As it is called in technical language, to work the form into the forefoot area. It means for me first of all to have the tape measure ready all the time, because now it is not only important to grind a pleasing last shape, but also to pay attention to my foot measures. I check the girth of the ball and of the instep during the grinding constantly. For the form it also has to be taken into account that the foot if asymmetrically built from the tarsus to the forefoot. This also has to be reflected in the last. In the area of the first metatarsal it needs to be stronger that in the fifth metatarsal.
In the next production step Franz Fischer shows me a new measuring device. The profile gauge with many thin rods is perfectly suited to take the shape of my foot from the plaster cast in an exact way. I push the gauge at the heel so long against the plaster cast of my foot, until all rods touch exactly.
Again and again I hold them to the last in order to grind the heel arch exactly according to the foot shape. Only when there is no more air between the profile gauge and the last, the foot shape and the last match. I use the same method for the outside and the inside of the last.

9. Step: Grinding the lower leg and the ankle joint
But the last still looks angular. Before we tackle the final shape, we make another model in the shape of the upper end of the plaster. This we transfer to the top of the last and gain orientation on how to design the curve of the calf and the ankle joint.We begin to break the edges and approach the round shape of the lower leg with each turning of the last on the grinding line. Here we pay very much attention to model the lateral and the medial malleolus in a clean way. Again the profile gauge helps us here to compare the foot shape with the last shape.

10. Step: Finishing
After the last step the former log of wood pretty much resembles a last. But the surface bears traces of the elaboration. Before we finish it, the measures and the position of the last are checked once more. Only then the grinding traces are removed with a pumicing device and an Engis-disc and the surface is smoothened. With a little bit of wax, worked in with a polishing disc, our work begins to shine and to my amazement it cannot be seen which last is made by me and which one has been ground by Franz Fischer.„Now you can make your own pair of shoes with them“, he says. But will all measures prove to be correct and will the shoe that will be manufactured over this last fit? I’ll have to find that out in another experiment.