Smoke and overtemperature sensor for 2020 extrusion

thingiverse

This is a more advanced detection system designed for installation in critical areas of the printer such as \r\n- Electronic box: detecting smoking/burning heated bed connectors, failing cheap PSU ...\r\n- Printing area (enclosed)\r\n\r\nThe unit features an FC22 print with a gas detection module on it like the MQ135 (suitable for detecting NH3,NOx, alcohol, Benzene, smoke,CO2), an NTC for overtemperature detection and a LED to signal fault conditions.\r\nSee detector specs [here](https://www.olimex.com/Products/Components/Sensors/SNS-MQ135/resources/SNS-MQ135.pdf)\r\nEverything fits together quite snugly.\r\nThe holes for the NTC are positioned so that they align with the 2 outer pins of the 6-pin connector, making soldering easy!\r\nStandard network cable was used with one pair for the NTC, 2 wires for GND, 2 wires for Vcc, one for the LED and the remaining one for the Digital (or analog) out\r\nNote that the detector module itself contains a heating element that draws 150mA (see specs). The effects of this on PLA when mounted in the warm top section of an enclosed printer have not been checked.\r\n\r\nThis was printed with a 0.6mm nozzle and 0.2mm layers in clear PC for the housing. The gas detector unit also has 2 LEDs on board: power on and alarm. These are visible through the housing.\r\nHousing and mounting are secured together using standard 16mm M3 screws. The bottom part has a smaller hole for the screws so they can be self-tapping. \r\n\r\n**Modification 20170923 **\r\nA hole was cut out on the bottom for easy access to the potmeter when using digital out.\r\nFurther documentation about this will be published on [Github](https://github.com/WalterSKW/SafetyProcessor)\r\n\r\n**Updated [Github](https://github.com/WalterSKW/SafetyProcessor) repository 20170928 **\r\nThe schematic diagram built on an Arduino Nano and the firmware can be found on Github\r\n\r\nTake a look at [Youtube too](https://youtu.be/euKyRw3iZ7g)\r\n\r\n**20171110 : Added PDF version of schematic diagram to GITHUB **\r\n\r\n**20171228 : Added PCB gerberfiles **