This was my submission with my partner, Alex Kerstein, to a design competition for a home coffee roaster on GE's open innovation platform, FirstBuild. While most products on the market are larger and expensive ($300-$1000), this approach is cost-accessible, using the oven as both the heat source and source of coffee bean agitation.
Pour in the beans
The first step is to place the beans into the transparent heating chamber, allowing yourself to watch the coffee turn from its raw green color and into the desired level of roast.
Attach it to your convection fan
Most modern ovens have a convective fan within their chamber. Connect the air tube using the high temperature magnets onto the outside of the fan to guide the hot air underneath the beans.
Keep the beans, ditch the chaff and smoke
Coffee beans require heat and movement in order to activate the oils and remove the papery shell. Directing the flow of hot air as a popcorn popper upward in a chamber past the beans, they both roast and de-chaff. The chaff is collected in a small cup and any smoke is collected by a carbon filter.
Air cool your little delights
Once the beans have roasted as desired, they need to be quickly brought to room temperature. There is a separate salad spinner-type device that rapidly air cools the beans using the roasting chamber. It efficiently moves the air like a rotating ventilation cap while centrifugally driving the beans up a wall for maximum convective cooling.
All modeling done in Autodesk Fusion 360 by Conrad Jahrling in 2016.