Bottomless Portafilter

Project Overview

For my ME103 (Designing and Making) Final Project, I decided to make a bottomless espresso portafilter. This is what coffee grounds are poured and tamped into, and it is critical in creating the perfect latte. ME103 gave me the opportunity to fabricate something with the correct time and space (both physically as well as mentally) where it would be almost ‘perfect’. I’ve been building, designing, and fabricating for a long time and while I think I’ve made some pretty cool things, this class gave me the perfect opportunity to machine something with uncompromising expectations. In that way, it reinforced the lessons of being detail focused and the promising reward of holding one’s creation to high expectations. It’s been awesome to have used my portafilter and have that sense of accomplishment and satisfaction.  It now lives on loan to family friends in Idaho who use it every day.

CAD Modeling

Final Product, Hero Shot, and Presentation (Meet the Makers)

As to the process itself, the design and CAD you see differs from my final project because of the iterative nature of design. I found myself constantly asking myself how to better fabricate the stainless steel, or how can the design of the portafilter be improved. This really came to a head when my first attempt failed dramatically during the milling with the indexing head. The main body of stainless was not well affixed to the chuck and the endmill almost acted as a starter motor to a flywheel and in the process it took big chunks out of the part forcing me to restart. Fortunately it was only Week 6. What had originally taken me about 8-10 hours to machine only took me about 3 on the second iteration. I also was able to make some design changes for the tabs so they would better mate to the grouphead on the machine (i.e. it would fit better on the espresso machine). Almost fortunately, the now messed up main body was a perfect prototype to re-try the indexing head milling and then subsequently try out the brazing process. I think the adage of ‘fail often and fail early’ really applied well to my project. The process as a whole went pretty smoothly but I’m glad for the failures I encountered and I’m glad they happened early on. Seeing the stainless part get torn up was a low point, but I feel pretty well conditioned to failure when making things (given a lot of experience working on old cars), and there happened to be a pretty awesome silver lining to that cloud.