Air Manager - Active Chamber Heater and Filter V0.5

Intro

A mostly finished Chamber heater + Filter for core one. It is able to switch between exhaust and circulation modes using an over center loaded flap + servo. The max temperature I have been comfortable reaching is 65°C, beacuse I don't know how the rest of the printer will behave. It is kinda bulky, at least compared to the size of the printer, so in the future I would like to scale it down, hence V0.5. 

The goal here is for everything to be filtered so you don't have to deal with fumes. It is exhaust based, so there should be no positive pressure issues that cause fume leakage. When exhausting you can open the top vent, or just let it pull air in from the back (because those fans are now disabled)

In terms of electronics, I am currently using an inkbird controller. It works fine but it can't communicate with the printer and isnt very consistent and sometimes majorly overshoots. I have an SSR (Photo 4) that I will integrate with the thermistor and a microcontroller. Somehow I want it to be able to communicate with the printer, maybe with the GPIO board.

Saftey disclaimer: Parts of this project use mains voltage. I am not an electrician so don't take how I wired everything as safe.

There are two live wires for the heater, two ground wires attached to the frame and the heater, the thermistor wire, and the servo wire. The hot wire has a thermal fuse. Thermistor wire and servo wire are kept seperate from mains wires.

Operating modes:

1. Filtered Exhaust (Flap set to exhaust, good for pla and petg)
2. Filtered Circulation (Flap set to circulate, heater disabled)
3. Filtered heating (Flap set to circulate, heater enabled)
4. Unfiltered Exhaust (Use original exhaust fans on the back) – The purpose of this is for select cases where you need extreme cooling and don't care about filtration, eg: PLA

Parts used:

1. Prusa Adv. Filtration kit
2. 110V 300W PTC heater (With thermostat removed)
3. 125C thermal Fuse
4. 10K NTC thermistor
5. Micro Servo
6. Thermal cement compound 
7. Scrap sheet metal bracket for mounting thermistor
8. Wago connectors
9. 14 AWG wire
10. Lots of M3 bolts and heat set inserts (Some low profile for asthetic reasons)
11. 4x M3 locknut
12. 3x M2x10 bolt and heat set insert
13. 3x M1.6 self tapper
14. 1x M4 bolt and nut (Uncoated for grounding)
15. 1x M5 bolt and nut (Uncoated for grounding, mounts to heater)
16. 2x 10mm OD 5mm ID 4mm WD bearing
17. 1x 21mm OD 15mm ID 4mm WD bearing
18. 1x Spring (For over center mechanism)
19. 0.2mm thick x 3mm width clear double sided tape (for sealing and mounting some parts)

I printed everything in ABS, PCCF for the heater parts, and TPU for the gaskets and seals. Note that all the over center/flap parts are quite fragile and need good dimensional accuracy. If you have a fire retardant filament (like polymaker PC-FR) I would use it here.

You need a side pocket expansion that I made in order to fit all the components. It has a sheet metal part which I got through OshCut: https://www.printables.com/model/1428433-side-pocket-expansion-for-core-one-sheet-metal I was too lazy to re-add all those files to this post

PTC heater notes:

By default, the heater I used (https://amazon.com/dp/B07PJB4TY7) comes with a thermostat installed. I removed this, and replaced it with a metal piping bracket (for 5mm diameter) to mount a thermistor and thermal fuse to. 

Electronics:

1. 40A SSR 
2. 15A IEC with 10A fuse
3. Wago connectors
4. 14 AWG wire
5. Prusa GPIO board
6. Arduino Uno R3
7. Cooling Fan
8. 10K resistor
9. 110V 300W PTC heater (as listed above)
10. 125C thermal Fuse (as listed above)
11. 10K NTC thermistor (as listed above)
12. Micro Servo (as listed above)

Version Notes:

• V0.5 (10/18/2025)
• Added more about wiring (10/22/2025)