The Ichi Hammer was a project that I used as a sandbox to experiment with the results of combining different manufacturing process in an educational manner. In the student shop where I taught, each new student manufactured a magnifying glass over the first few weeks of the quarter. Through the different parts of the project, the student learned different processes: he or she would turn the axially symmetric components, mill a separate piece, and silver braze two parts together. I was interested in bringing in a few other areas of our shop as well. For example, while additive manufacturing is an increasingly important part of a manufacturing and prototyping sequence, it is sometimes substituted for processes where it is not an adequate solution. That being said, in a small-run production run, it can be a very powerful tool. Separately, sand casting, while an essential process in our shop, was not integrated into the standardized magnifying glass project. We had recently refreshed our shop's capability to do cored sand castings, as well, and we lacked an introductory project for students interested in exploring the process.
The Ichi Hammer was a first pass at an update to the standardized magnifying glass. My goal in designing this project was to make something that students could keep and use on a daily basis through the rest of their time in our shop. The hammer head is cast aluminum with provision for standardized replaceable striking faces. The center of the head has a cutout designed for use on a 3/4" mill drawbar. This way, a student can use the hammer as a mill wrench and also use the faces to either fixture work or loosen a stuck drawbar. Rather than post-machine away the material to make this cutout, I designed a core that would build this geometry right into the casting. Both the pattern and the core box were 3D printed as examples of the benefits of additive manufacturing in conjunction with other processes. The hammer head requires one session of post-machining, mostly from one orientation. There's still some work to go in making it an accessible first project, but it's a start.