i wanted a active chamber heater that only used the printer psu so i made one takes about 45 minutes to an hour to get the chamber to 80c if you want faster you must upgrade psu and upgrade the heater from 180 watt to 300 watt

the hole size to cut for the controller is 72.1mm x 39.2 mm, with the machine laid on its back preferably on a padded surface so not to scratch or ding the back panel 

remove the screws holding the bottom panel on on the top left there are two stand offs “where the screws go ” cut the hole between those positioning the cut all the way to the bottom the bottom panel will hold the controller in place 

pull power for one heater wire directly from the psu then set a ground wire up run it into the s1 slot on the controller then take a second wire and run it from s2 to the ground of the heater i hooked the fan up to the same wires so it comes on when the heater turns on 

https://www.amazon.com/Constant-Temperature-Electric-Heating-Incubator/dp/B07F3S2G9Q/ref=sr_1_5_sspa?crid=2ZNHQDQ87YEBM&dib=eyJ2IjoiMSJ9.885hW54VZOQMpjIL0RdOzSMpRpteAthtO04FQxXAiY9YZG_gwS9XE4pw8TdB7TVJ4bbI7u2t9phSAyDP3fX-A_JA05Tx0XoEt1MLGEZV9NJm1sIzr3vZHjekIlcQIdgJ1ji6nhR13KzuPwUA-cuDd5LdkAHJQ-VERoEZ14qyIwBzfymKUnbQRC-Gvk3XT7p83yufxvykJKCwKBqVXT1cibcTm0E0d6L2aNEOjjhABZtoZyuqKc_SsjTPVdXfhdFCplxtLNZ3v5vkSGXkGAGcUTUJ3GAzmk6MyCuii5a_c90.PktXrmSPOkwwft45esloOgqqyW2v0DYY8-n79zrGU3A&dib_tag=se&keywords=180%2Bwatt%2B24%2Bv%2Bheater&qid=1758588896&s=home-garden&sprefix=180%2Bwatt%2B24%2Bv%2Bheater%2B%2Cgarden%2C171&sr=1-5-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&th=1

then take a hot wire from the psu add it to the controller where it says vcc then add a final ground where it says ground run that back to the psu all these two do is power the controller and turn the switch on and off for the heater they do not power the heater they power a relay i struggled with this myself lol

amazon.com/gp/product/B08FT39BS3/ref=ox_sc_act_title_2?smid=A39S0U3UP1U7UG&psc=1

so you should have a ground from psu to s1 on controller the s2 on the controller hooks to the groundwire for the heater then you should have a hot wire from the heater directly to the psu as well lastly a final set of hot and ground running to the controller from the psu and plugged into they're marked spots 

if anyone has any suggestions on how to improve the design feel free to tag me in the remix thank you and happy printing engineering grade filaments on a 300 dollar printer lol