Gaggia Classic Steam Knob

thingiverse

I modified this excellent knob design slightly, and repurposed it for use as a steam knob for the Gaggia Classic espresso machine. I didn't like the stock knob for 2 reasons: it is smooth, and it can be hard to pull off when you are disassembling things. The design requires a 6mm d-hub, which screws onto the knob using 4 6-32 screws (3/8" to 1/2" length). The hub/knob then mounts to the steam valve shaft. The diagrams show the hub that I used, which I got from servocity.com. Others exist, although the mounting holes may need to be modified for a different hub. Since the design uses a grub screw, it is very easy to remove when needed. The design includes a cap for the end. This can be easily removed by poking a thin object through the center hole from the bottom. I used ABS for this, due to the high temperatures the steam valve shaft can see. PETG should also work. PLA is not recommended.