In general, for older, un-calibrated Bullets, the new calibrations will lower the exhaust fan RPM and make the steps smaller and more consistent between each setting, allowing more fine control of airflow during the roast. You will still be able to run full fan speed.

It is also possible to disable this feature in the menu option and use the old type of RPM control.

Follow these steps to calibrate (or re-calibrate) your exhaust fan:

  1. Take off your chaff collector. (Please note: NOT just the chaff filter.)
  2. Turn on the Bullet and go to the menu section 6 by clicking F1 until the clock LED shows 6.
  3. Press the “A” button (top left button). If no calibration has been done before this should start the process.
  4. Start the calibration process by clicking both Fan buttons (Up and Down) at the same time.
  5. Now the calibration will begin. It will take about 5 minutes to complete. When it is finished the Bullet will beep for two seconds.
  6. You can toggle between un-calibrated or calibrated fan speeds by clicking the “A” button in menu 6. Three dashes (- – -) denotes un-calibrated mode, while P-d means calibrated. You can toggle between calibration settings for the old motor vs the new motor by pressing the power keys. bl-16 is the setting for the old fan motor (serial #001 – #2371). bl-26 is the setting for the new fan motor (serial #2372 and above.)