Moving Bed Thermistor for Heated Chamber Control

So I made a quick "heated chamber" with some styrofoam insulation boards just to see if it would help print strength (it definitely did) and quickly found that it's too difficult to keep the air temperature constant. I'd rather not have to add a separate circuit for temperature control, so would moving the bed thermistor to a place near the print bed, but not on, work? The bed would then just be used as a space heater and the thermistor would measure air temperature (I would lower it of course from typical bed temps). I don't know much about PID, but I'm worried if there's too much distance between the bed and the thermistor, it might push the bed temperature too high. Any thoughts?

No I don't think that would be a good idea. You want to control the bed temperature quite accurately to a different temperature to the air.

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[www.hydraraptor.blogspot.com]

Ah alright. Is it possible to give me a general outline of what I need to do to control another heater based on a separate thermistor with the melzi?

You would need to duplicate the heater MOSFET circuit, which is just a MOSFET and the thermistor circuit, which is just a resistor and capacitor and connect them to spare I/O pins on the Melzi expansion, connector.

For firmware you could probably define it as a second extruder and control its temperature then way.

Some people use heaters with off the self PID controllers.

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[www.hydraraptor.blogspot.com]