This is a more elaborated detection unit to be mounted on critical places in the printer like
- Electronic box : detection of smoking/burning heated bed connectors, failing cheap PSU ...
- Printing area (enclosed)
The unit has an FC22 print with a gas detection unit on it like the MQ135 ( suitable for detecting of NH3,NOx, alcohol, Benzene, smoke,CO2) , an NTC for overtemperature detection and a LED to signal fault conditions.
See detector specs here
Everything has a quite tight fit.
The holes for the NTC are placed so that they land on the 2 outer pins of the 6pin connector. Easy to solder like that!
I used standard network cable 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
Keep in mind that the detector module itself contains a heating element that draws 150mA (see specs). I didn't check the effects on PLA when mounted in the warm top section of an enclosed printer.
I printed this with a 0,6mm nozzle and 0,2mm layers in clear PC for the housing. The gas detector unit has also 2 LEDs on board : power on and alarm. These are visible through the housing.
Housing and mounting are screwed together using standard 16mm M3 screws. The bottom part has a smaller hole for the screws so they can be self tapping.
Cut out a hole on the bottom for easy access to the potmeter when using digital out.
Further documentation about this will be published on Github
Updated Github repository 20170928
You can find the schematic diagram build on an Arduino Nano and the firmware on Github
Have a look on Youtube too
20171110 : Added PDF version of schematic diagram to GITHUB
20171228 : Added PCB gerberfiles