Why Upgrade Your Voron 2.4 Enclosure?

Why Upgrade Your Voron 2.4 Enclosure?

The Voron 2.4 is one of the most capable open-source CoreXY 3D printers available, but out of the box—even with the standard acrylic panels installed—its enclosure has two significant weaknesses for printing engineering filaments like ABS, ASA, and Nylon. First, the sealed chamber accumulates styrene fumes and ultrafine particles (UFPs) that are both unpleasant and potentially harmful during long prints. Second, passive chamber heating from the bed alone often struggles to reach and maintain the 50-60°C chamber temperatures that prevent ABS warping and interlayer delamination on large parts. This guide covers two complementary upgrades: installing a Nevermore activated carbon filter for air quality, and adding active chamber heating for temperature control.

I’ll assume you have a fully assembled and functioning Voron 2.4 (any size—250mm, 300mm, or 350mm). The upgrades described here are fully compatible with both stock Vorons and those running common mods like Stealthburner, Tap, and CAN bus toolhead boards. All printed parts mentioned are available from the Voron Users repository on GitHub or popular mod sites like Printables.

Part 1: Nevermore Filter Installation

The Nevermore filter is an open-source activated carbon filtration system originally designed by nevermore3d for the Voron community. It recirculates chamber air through a bed of activated carbon pellets, scrubbing VOCs (volatile organic compounds) and capturing UFPs. Several versions exist, but the Nevermore V5 and Nevermore Micro V6 are the current recommended designs for Voron 2.4 installations.

Choosing Your Nevermore Variant

Model	Fan Size	Carbon Capacity	Best For	Mount Location
Nevermore V5 Duo	2x 5015 blower	~300g carbon	350mm+ printers, high-temp ABS	Rear chamber floor, behind Z drives
Nevermore V5 Solo	1x 5015 blower	~150g carbon	250/300mm printers	Side or rear chamber floor
Nevermore Micro V6	1x 4020 or 5015	~80g carbon	Compact builds, stealth installations	Under-bed carriage or back panel
Nevermore StealthMax	1x 6028 axial	~200g carbon	Maximum airflow, quiet operation	Rear exhaust area

For most Voron 2.4 users, the Nevermore V5 Solo represents the sweet spot of filtration capacity, airflow, and ease of installation. The Micro V6 is ideal if you’re space-constrained (e.g., running a kinematic bed mount or a purge bucket that occupies the rear floor area).

Bill of Materials

For a Nevermore V5 Solo installation, you’ll need:

• Nevermore V5 printed parts (ABS or ASA, 4 perimeters, 40% infill minimum)
• 1x 5015 radial blower fan (24V, dual ball bearing—Delta or Sunon preferred, avoid generic sleeve bearing units)
• ~150g of acid-washed activated carbon pellets (4mm pellet size, “VOC carbon” from Nevermore recommended sources or aquarium-grade carbon)
• 4x M3x8mm BHCS screws (fan mounting)
• 4x M3 heatset inserts (for lid attachment)
• 4x M3x12mm BHCS screws (lid-to-body)
• 1x section of carbon-infused HEPA pre-filter foam, if desired (for UFP capture alongside carbon)
• 2x JST-XH or Microfit 3.0 connectors (for fan power)
• 24V power source: either a spare fan port on your controller board or a dedicated buck converter tapped off the PSU

Printing the Nevermore Parts

All Nevermore parts must be printed in ABS or ASA—never PLA or PETG, which will warp and off-gas at chamber temperatures above 50°C. Recommended print settings:

• Material: ABS (eSun ABS+ or KVP preferred) or ASA (Polymaker ASA)
• Nozzle temperature: 250-260°C
• Bed temperature: 100-110°C
• Chamber temperature: 45°C minimum (soak for 30 minutes before starting print)
• Perimeters: 4
• Infill: 40% gyroid
• Supports: Not required if oriented correctly
• Brim: Yes, 5-8mm—ABS/ASA parts of this size will warp without it

The carbon cartridge lid prints face-down on the build plate. The main body prints upright. Both parts should be printed with the seam aligned to the rear (non-visible) face. After printing, check the fan mounting surface for flatness; if your first layer was slightly overextruded, use a deburring tool to clean up the fan seat for a good seal.

Assembly and Installation

Step-by-step Nevermore V5 Solo assembly:

1. Press the M3 heatset inserts into the four corner bosses of the main body. Set iron temperature to 285°C for ABS parts; let the insert cool completely before threading.
2. Install the 5015 blower fan into the inlet port on the main body. The fan label faces inward (toward the carbon chamber). Secure with M3x8mm screws. Route the fan wires through the dedicated wire channel in the body.
3. Fill the carbon cartridge with ~150g of activated carbon pellets. Do not overpack—leave 2-3mm of headspace below the lid for airflow distribution. Tap the cartridge gently to settle the pellets.
4. If using a HEPA pre-filter, cut a 50x80mm section and place it in the airflow path upstream of the carbon bed. Replace this pre-filter every 200 print hours.
5. Attach the lid with M3x12mm screws. Do not overtighten—just snug enough to compress the lid gasket (if your Nevermore variant includes one).
6. Mount the assembled unit to the rear chamber floor using VHB tape or the dedicated bracket if your frame includes one. Orient the exhaust port toward the center of the chamber for even circulation.
7. Wire the fan to a controllable 24V fan port on your MCU. On Octopus boards, use any free fan port (e.g., FAN2). On SKR or BTT Manta boards, verify the fan port supports the 5015’s current draw (typically 0.15-0.2A at 24V).

Klipper Configuration for the Nevermore

Add the following to your Klipper printer.cfg to control the Nevermore fan:

[heater_fan nevermore_filter]
pin: PA2  # Your fan pin; verify in your board's pinout
heater: extruder
heater_temp: 50.0
fan_speed: 0.8

This configuration runs the Nevermore at 80% whenever the extruder temperature exceeds 50°C, which is anytime you’re printing. For more granular control, use a [controller_fan] definition tied to the chamber thermistor or a macros-based trigger. Many builders combine the Nevermore with a chamber temperature sensor and run the fan at 100% during the first 5 minutes of the print to rapidly circulate warm air, then reduce to 60% for steady-state filtration.

Carbon replacement schedule: Activated carbon saturates after approximately 100-150 print hours of ABS/ASA printing. You’ll know it’s time when you start smelling styrene during prints. Buy carbon in bulk (2-5 kg bags) and vacuum-seal portions for storage—exposed carbon absorbs moisture and VOCs from ambient air, reducing its active life.

Part 2: Active Chamber Heating

Passive chamber heating (relying solely on the heated bed to warm the enclosure) typically achieves 40-50°C after a 30-minute soak on a 350mm Voron. This is adequate for small ABS parts but marginal for large, flat parts that are prone to warping at the edges. Active chamber heating pushes the enclosure to 55-65°C, dramatically improving layer adhesion and reducing warping on full-plate ABS prints.

Approach 1: Dedicated Chamber Heater (PTF Heater)

The most effective method is a dedicated Positive Temperature Coefficient (PTC) heater element. These self-regulating heaters typically draw 300-500W and include an integrated fan for forced-air circulation. The community-favorite option is the 400W PTC heater module available on AliExpress for roughly $25-35. It runs on mains voltage (110-220V AC) and requires a solid-state relay (SSR) controlled by the MCU with a chamber thermistor.

Required components:

• 400W PTC heater with integrated fan (120V AC or 240V AC depending on your region)
• Solid State Relay (SSR), 40A minimum (Omron G3NA or Fotek SSR-40 DA)
• Chamber thermistor (100K NTC 3950, same as Voron bed thermistor)
• AC wiring: 14AWG stranded wire, crimp terminals, DIN rail mount for SSR
• Thermal fuse (optional but strongly recommended: 85°C cutoff, wired in series with heater AC input)
• Mains inlet and outlet for pass-through wiring from PSU

Safety disclaimer: Mains voltage wiring is dangerous. If you are not comfortable working with 120/240V AC, seek help from a qualified electrician or use the DC bed-only heating approach below. Always include a thermal fuse. Earth-ground the printer frame. Use properly rated connectors and insulation.

Klipper Configuration for Chamber Heater

Define the chamber heater, thermistor, and safety limits in printer.cfg:

[thermistor chamber_thermistor]
temperature1: 25.0
resistance1: 100000
beta: 3950

[temperature_sensor chamber]
sensor_type: NTC 100K MGB18-104F39050L32
sensor_pin: PF3  # Your ADC pin; check your board's pinout
min_temp: 0
max_temp: 80

[heater_generic chamber_heater]
heater_pin: PE5  # Heater output pin; verify for your board
sensor_type: NTC 100K MGB18-104F39050L32
sensor_pin: PF3
control: watermark
max_power: 1.0
min_temp: 0
max_temp: 70

[verify_heater chamber_heater]
max_error: 120
check_gain_time: 120
hysteresis: 5
heating_gain: 1.5

[gcode_macro CHAMBER_HEAT]
gcode:
    SET_HEATER_TEMPERATURE HEATER=chamber_heater TARGET={params.TARGET|default(55)|float}
    M118 Chamber heating to {params.TARGET|default(55)}C

With a 400W PTC heater, a 350mm Voron 2.4 enclosure reaches 55°C in approximately 8-10 minutes and 65°C in 12-15 minutes. The verify_heater section protects against thermistor failure or SSR latch-up by disabling the heater if the temperature doesn’t rise as expected within the gain time window.

Approach 2: Bed-Only Soak with Nevermore Circulation

If you prefer to avoid mains voltage in your printer, a simpler (though slower) approach uses the heated bed plus the Nevermore fan for active air circulation. Configure a PRINT_START macro that soaks the chamber:

[gcode_macro PRINT_START]
gcode:
    # Home and QGL
    G28
    QUAD_GANTRY_LEVEL
    
    # Heat bed to ABS temperature
    M140 S110
    
    # Set Nevermore to 100% for circulation
    SET_FAN_SPEED FAN=nevermore_filter SPEED=1.0
    
    # Wait for chamber to reach target
    TEMPERATURE_WAIT SENSOR=chamber MINIMUM=45
    
    # Soak for additional 10 minutes for thermal equilibrium
    G4 P600000
    
    # Heat extruder, mesh, purge, and start print
    M104 S250
    G28 Z
    BED_MESH_PROFILE LOAD=default
    ...

This approach takes longer (30-45 minutes for a 55°C chamber from cold) but requires no additional hardware beyond the Nevermore and a chamber thermistor. For most ABS prints, reaching 45-50°C chamber temperature is sufficient for warp-free results on parts up to ~200mm in the XY dimension.

Insulation and Sealing for Maximum Efficiency

Both the Nevermore and chamber heater benefit from a well-sealed enclosure. Common leakage points on the Voron 2.4:

• Panel gaps: Apply 1mm-thick adhesive foam weatherstripping to the aluminum extrusion where acrylic panels seat. This simple mod improves chamber temperature stability by 3-5°C.
• Z-belt pass-through slots: The slots in the bottom panel where Z belts exit are major heat leaks. Print TPU plugs or use adhesive foam to seal these gaps.
• Top hat / exhaust filter: If using the stock exhaust fan, block it with a printed cover or foam plug during ABS prints. The standard configuration exhausts valuable chamber heat.
• Door gaps: Adjust the door hinges and latch for a tight seal. Aftermarket door seals (3M hollow D-profile weatherstrip) are available from Voron vendors.
• Bottom panel insulation: Adding a sheet of 6mm cork or closed-cell foam under the bottom panel significantly reduces heat loss through the base. The SpecKB board from Fabreeko includes integrated cork insulation; a DIY version costs under $10.

Electronics Cooling Considerations

With an actively heated chamber at 60°C+, your electronics bay (located under the deck panel, isolated from the chamber by the bottom panel insulation) still requires active cooling. The stock Voron design uses two 6025 fans pulling cool air through the electronics bay. At elevated chamber temperatures, these fans work harder. Verify that your MCU, Raspberry Pi, and PSU remain below their rated operating temperatures:

• Raspberry Pi: Max operating temperature 85°C (throttling starts at 80°C). Add a small heatsink and 30mm fan if the Pi exceeds 65°C under load.
• MCU (Octopus/Manta/etc.): TMC drivers start missing steps above 100°C. Measured electronics bay temperatures rarely exceed 50°C even with a 65°C chamber, but verify with an infrared thermometer.
• PSU (Mean Well LRS-350 or UHP): Rated for 50°C operation with derating above. If your electronics bay exceeds 45°C, upgrade to a UHP series PSU (rated to 70°C) or add a dedicated PSU cooling duct.

Testing and Validation

After completing both upgrades, validate the system with a test print:

1. Set up a chamber temperature graph in Mainsail/Fluidd. Verify the chamber reaches your target temperature (55°C for ASA, 45-50°C for ABS) within 15 minutes with active heating, or 35 minutes with passive heating.
2. Print a 200x200mm single-layer ABS square (0.2mm layer height, 100% flow, no part cooling fan). This torture test reveals any warping tendencies. Edges curling more than 0.5mm off the bed indicate insufficient chamber temperature or uneven heating.
3. Print a standard Voron test cube. Measure the top surface with a straightedge—it should be dead flat with no “taco” deformation.
4. Conduct the “smell test”: After 2 hours of continuous ABS printing with the Nevermore running at 80%, there should be zero detectable styrene odor outside the enclosure. If you smell ABS, check Nevermore carbon saturation and door/panel seals.

Conclusion

The Nevermore filter and chamber heating upgrades transform the Voron 2.4 from a capable PETG/PLA printer into a true engineering-grade ABS/ASA workhorse. The Nevermore handles air quality, making it practical to run 30-hour ABS prints in an occupied home without respiratory concerns. Active chamber heating eliminates the warping and delamination that plague large ABS parts, producing dimensionally accurate prints that rival commercial Stratasys machines. Together, these two upgrades represent perhaps the highest-value modifications in the entire Voron ecosystem—total cost under $80 in parts, an afternoon of installation, and a permanent improvement in print quality and user experience.