Use second nozzle heater to control chamber heating

So I created enclosure for my TAZ4. It made ABS prints a little bit better, but still not perfect. It still curls. I measured about 90F inside chamber when using 80C for heated bed. Going higher with heated bed makes prints worse.

So I went ahead and bought 250W infrared lamp in Lowes. Curling went away completely! But I got other issues - it was clearly heating it too much and not quite even. So next what I want to try - 150W lamp and control it via second nozzle heater. I already found solid state relay, which can be triggered by 24V to control infrared lamp, but I was wondering what I need to do to be able to change second hotend temperature independently from bed temperature (right now both seems to be coupled)

Any clues?

You would need to install a new firmware that is configured for 2 extruders. I’m not sure if you can get away with using one of the Lulzbot dual extruder firmwares or if you need to be a bit more precise. It may depend on which hot end you are currently using. Also, if you did do this you would need to wire up a thermistor too or the printer will think there is a problem and won’t let anything work.

yeah, already ordered thermistors to measure ambient temperature (or maybe i should measure frame temperature - going to experiment.) Just noticed that in my TAZ4 hotend2 temperature is always set to what bed set at, so it is clearly something needs to be tweaked when I install second thermistor.

You mentioned Lulzbot dual extruder firmware, do you know by any chance url/something where I can get one? I want to compare two to see differences.

http://devel.lulzbot.com/TAZ/accessories/dual_extruder/dual_extruder-1.0/software/

Thanks! I will play with it!