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Automating the Quest
Because the Quest roasters are entirely manually operated, with no special hardware and no firmware,
they lend themselves easily to automation. While most Quest buyers select them because they are
simple, manual roasters, several owners have already automated theirs. It is not our intention to do a
deep dive into automating the Quest. Here are some basic ideas.
MET/ET/BT Control:
Arguably, the Quest should have some form of control over the temperature,
especially MET. In its stock form, providing one continues to reset the power switch, the roaster will
get increasingly hotter until the heaters fail. By connecting a thermostat to a thermocouple installed in
the MET position, the user can select a maximum MET. The temperature will move up and down in a
sawtooth pattern when the roaster gets to the thermostat’s set point. The on/off cycles’ frequency and
depth depend on the thermocouple’s mass and the thermometer’s deadband. In practice, the operator
would likely run the roaster so that it never gets this hot. This modification would thus be considered
something to add for safety.
A better implementation for temperature control would be to use a PID driven by the BT, not the MET.
However, users report that it is challenging to adjust the PID parameters for optimum operation. Note,
however, that the BT thermocouple temperature is not an actual measurement of BT. Also, electric
drum roasters such as the Quest are not very responsive; it takes some time for heater current change to
be seen as a change in ET and even longer to change the BT.
Just as one can use Artisan to display and record roasting parameters, it has inbuilt capabilities to
control a roaster. This video, while not Quest-specific, provides some good information.
Written by Maurice Nunas, with contributions from other Home-Barista members, including CarefreeBuzzBuzz, LLC and
‘spromance’. To contribute additional material, suggest edits and to comment, please email to <nunas_at_nunas_dot_com> .
© 2021 This document may be distributed by anyone in print or electronic form, providing it is done so free of charge,
without altering it in any manner.