Flair Pro 2 Mechanism Conversion
Background
You could call me a coffee enthusiast. I enjoy brewing with many methods, one of my favorites being espresso. I first started making espresso with a Flair lever espresso press. If you’re unfamiliar with the process, coffee grounds and hot water are put in the device, and a lever is used to generate pressure on the water which is forced through the grounds.
This works, and Flair makes a good machine at a reasonable price point. There is always room for improvement, though.
The primary issue I have with it is that the lever doesn’t give the mechanical advantage that I think is necessary. In other words, you have to push very hard to brew your coffee. You may notice in the photo of the unmodified version the person using two hands. That is necessary.
The second issue I have with it is this. Once finished brewing, the lever is lifted to depressurize the chamber and stop the brew process. There will be excess water in the chamber, near boiling. This extra water will be pressurized and will push either the plunger or brew chamber up. By design the plunger is supposed to move up for depressurization. If, however, the brew chamber moves up, the entire contents of the chamber will be emptied on your coffee, hands, and counter. Very frustrating.
Design Decisions
I chose a screw to replace the lever mechanism for its low cost, ease of implementation, and flexibility. More on that last part later.
Basic geometries were captured using calipers, micrometers, and some pictures. What was their pivot became a bolted connection to attach the “head” of the new press. This bolted connection is allowed to pivot, and this movement is used to positively capture the brew chamber during the brew process (see last two pictures). This solves my second issue with Flair’s machine.
The second picture shows the first prototype. This I printed in PLA, and it was strong enough to test the machine and pull a few dozen shots. The handle and knob were also printed parts, they held up well for the most part.
In the fourth picture you’ll see what I meant by “increased flexibility” earlier. The screw mechanism allows me to press against anything, including a custom tamper. The well-centered screw aligns the tamper well, providing a more level tamp. The reduction in effort and increased precision during tamping has drastically improved my workflow.
The latest iteration is the machine shown in the last four pictures. I converted the head to a billet part and also replaced the handle with a turned stainless steel part. The handle is by no means a final design, it’s just the stock I had on hand and a basic, easy to manufacture design.
This project is still a work in progress, but I do intend to move the design towards a finished product that could become a kit sold here.
Design time: 7 hours
Manufacturing time: 3-4 hours
