This project aims to make freely available the 3D models and techniques to make open-backed, wooden-soled clogs using digital tools. Most shoes contain various types of plastic. Clogs are cool, comfortable, and made from sustainable materials. The clogs described here are made using a CNC router to carve the wooden sole, and also the last which is used to form the leather for the uppers. The moulded leather is then trimmed by hand, and nailed to the sole with small upholstery nails. All the files and a full description of how to make them can be downloaded as a zip file from the link at the bottom of the page. The 3D models are for only one size, (ladies size 4) so the models will have to be scaled to make bigger or smaller sizes. It is hoped that other makers will contribute with files for other sizes and we can build up a downloadable collection.
3D computer model of wooden sole 
3D computer model of shoe last
The files for the wooden soles and the lasts were modelled in Blender and exported as stl files. You will have to use a gcode generator like BlenderCam to make the 3D toolpaths for your CNC router in order to carve these shapes in blocks of timber like beech, alder,or ash.
Carved wooden shoe soles 
Carved wooden shoe last
These images show a last and a pair of wooden soles after they have been cut on the CNC router and cleaned up. Notice the piece of wood screwed to the bottom of the last. This is a sacrificial piece that can be replaced when it has been damaged by too many nails.
Stretching and nailing the leather upper to the shoe last 
Nailing the leather upper to the wooden sole
I used 2.5 mm thick ‘Veg Tan’ leather because it can be moulded into compound shapes by soaking in warm water. It is then stretched tight over the lasts, nailed in position, and left to dry overnight. Once the leather has dried the upper has to be carefully trimmed to fit into the ledge cut into the sides of the wooden sole. It is then nailed in place using small upholstery nails. Finally, the back of the leather upper will have to be trimmed, and a rubber sole, made from car inner tube, glued to the bottom to prevent the clogs wearing down too quickly.
And that’s it. Slip them on and try out your first clog dance steps.If you need some inspiration check out; https://www.youtube.com/watch?v=YeMrOimkzxE
If you enjoyed this tutorial and have made some clogs please let me know. And if you have any comments, suggestions, or 3D models for new sizes it would be great to add them to the files.
Download the 3D models and instructions from here.
Digi Penn
Incredibly interesting project. Look forward to reading more about this.