Chamber heater recommendations?
I am trying to tie up some design aspects on a new 350x350x550 coreXY build I've been working on when I realized I hadn't considered adding a chamber heater.
What ideas are some of you running with? Safety is the #1 priority of course followed by a clean and professional look.
I have a SSR that controls an AC heat gun that is placed inside my chamber. I did have to cut the power cable and splice it into the SSR. But I'm fairly comfortable wiring mains wires. It holds temp very well.
Do try to get your motors and other electronics outside the chamber if you're going to actively heat it. I can only run mine at about 40C before the motors get to hot, and the heat creep causes PLA to clog. Running ABS at 40C has no issues with heat creep.
You may find that the heat from the bed is sufficient to keep the chamber warm enough for your purpose.
If bed heat alone is insufficient (and I'd say it usually is sufficient if your bed heater is adequate, and your enclosure is built around the build volume, not the entire printer), then I've made a heater using an aluminium electronics heatsink around 140x100mm and a 240v silicone heater pad bonded to it as you would for a bed (with an SSR10DA). You could use DC, if you have a suitable spare heater output or external mosfet to handle the current. Drill a hole for a thermistor/pt100/pt1000 and you can control it just as you do a heated bed. Mine is 200w and will self-limit at about 95 degrees, or I regulate it by PWM at about 80 deg C which keeps my chamber at 45 deg C, or so.
I had very limited success placing my temp sensor in the chamber air and then asking the firmware to use it to control a heater, they are just not coupled well enough, the bed heater is independent and therefore add heat unexpectedly to the chamber, and the thermal safety is a bit too rigorous (rightly so for hotends/beds) for this type of setup and throws heater faults too often. In any case for any given bed temp and chamber heater temp (for abs for example) you will be able to set a fixed temperature to achieve the air temperature you want.
However do use a spare thermistor channel to have a chamber air temp sensor in there.
Halogen lights are very effective at heating with the additional benefit of adding light. You can buy the cylindrical type and a dimmer to control/set the intensity at home improvement stores. I solder the wiring directly to the contacts to avoid having to add receptacles.
There's a link to a NASA project towards the end of this article using halogen lights for heating.