The BCN3D Sigma R17 includes numerous enhancements, including the redesign of the Extruder Board, the interface board between the main board and the printhead elements.
This redesign has had as objectives the reduction of the noise of the machine and the improvement in the efficiency of the subset.
At the hardware level, electronics components have been added that actively monitor the temperature of the hotend and only turn on the heatsink fan from a certain temperature. This way, if you only print with one material, only one fan will be turning.
To get a little more in detail, the key component is the LM392. It consists of an operational amplifier and a comparator adjusted (with hysteresis) to switch a FET when a certain voltage is reached determined by the hotend temperature sensor. This results in the heatsink fan turning on around 90-95 °C.
Taking advantage of the redesign, we replaced the noisy 24 Volt heatsink fan to a 12 Volt, greatly improving airflow management and practically eliminating noise.
The design has been designed so that all users of the BCN3D Sigma can benefit. It is possible to purchase the upgrade kit in the online store and replace the items to have the improvements directly. It is not necessary to modify the firmware or make adjustments via software.
All instructions for incorporating the new elements are available on the web.