Voron Top Hat Extension Mod — Taller Enclosure Guide

Enclosure Mod Z-Axis V2.4 Trident

One of the most common requests from Voron owners is simple: "I wish my printer was taller." The stock Voron V2.4 300mm has a Z-height of 300mm, which is adequate for most prints but restrictive for tall functional parts, large vases, helmets, or multi-part assemblies printed vertically. The top hat extension mod addresses this by adding a taller top enclosure section, giving you 60-200mm of additional Z-height.

Last updated: May 2025. This guide covers everything about the Voron top hat extension mod: why it's useful, parts needed (frame extrusions, panels, belts, z-axis components), step-by-step assembly and installation, difficulty level, China-direct pricing, compatibility, and before/after benefits.

What Is a Top Hat Extension?

The "top hat" on a Voron V2.4 or Trident is the upper enclosure section that sits above the main frame, housing the Z-axis lead screws, gantry top, and electronics bay (on V2.4). In a stock build, the top hat adds about 100-150mm above the build volume. The extension mod replaces this with a taller top hat section, effectively raising the roof of the enclosure.

There are two main approaches:

• Standard extension (60-100mm): Replaces the existing top hat extrusions with longer ones. Requires longer Z-axis belts (for V2.4) or longer lead screws (for Trident). This is the most common and practical extension for most users.
• Major extension (120-200mm): Adds an entire extra layer of extrusion between the main frame and the top hat. Requires significant hardware changes: longer Z belts, longer lead screws, longer cable chains, and potentially different Z motor mounts. This is a major project.

Why Is This Mod Useful?

Taller functional parts: Print full-height helmet visors, large enclosures, or multi-part assemblies without splitting models. A 360mm Z-height (V2.4 300mm + 60mm extension) fits most wearable prints.

Multi-part printing without stacking: Print multiple tall parts simultaneously on the same build plate without worrying about Z-height limits. This increases throughput for production environments.

Better material utilization: Taller prints consume more filament per print but reduce the number of print jobs needed for large assemblies. This means fewer start-up sequences, less purge waste, and more time printing.

Future-proofing: As hotends and extruders improve, print speeds increase — and faster printing means you can fill a taller Z-height in the same time. A 300mm Z-height becomes a bottleneck as volumetric flow rates improve.

Resale value: A Voron with extended Z-height is rare and desirable. If you ever sell your printer, the extension mod adds significant value.

The trade-off: Taller printers are more prone to Z-wobble, require longer chamber heat-up times, and need more space. The extension also adds cost and complexity to the build.

Parts Needed — Standard Extension (60-100mm)

Additional parts for Trident: Lead screw nuts (POM anti-backlash recommended), Z motor spacers if needed, and potentially longer Z motor wires.

Parts Needed — Major Extension (120-200mm)

For a major extension, you need everything above plus:

• 4x additional 2020 extrusions for the spacer layer (matching your XY frame dimensions: 300mm or 350mm)
• 8x additional corner brackets (for the spacer layer corners)
• 2x additional panel side panels (for the spacer layer)
• 1x additional back panel section (for the spacer layer)
• Extended Z-axis belts (significantly longer — calculate total travel + safety margin)
• Extended cable chains for all axes (check your existing chain lengths)
• Potentially longer stepper motor wires or a CANbus toolhead board to simplify wiring
• Re-printed enclosure parts (corner covers, top hat gussets, etc. if your extension changes the geometry)

Total for 120-200mm extension: ~$160-280 China-direct depending on panel material and hardware choices.

Assembly and Installation Steps

Step 1: Plan and Measure

Decide on your extension height. Common choices are 60mm (small, easy), 100mm (most popular, noticeable improvement), or 150mm (substantial, major work). Measure your available vertical space — make sure the extended printer still fits in your workspace with room for the exhaust fan and filament path on top.

Step 2: Order Extended Frame Extrusions

Most Voron builders source extrusions from the same AliExpress stores they used for the original build. The top hat vertical extrusions (4x) are the key part. For a V2.4 300mm stock top hat, the verticals are 150mm. For a 60mm extension, order 210mm. For 100mm, order 250mm. Make sure the supplier deburrs the cut ends — rough edges will scratch the enclosure panels.

Step 3: Cut or Order New Panels

The back panel needs to be taller. The top panel is usually reused. If you're doing a major extension with a spacer layer, you'll need two new side panels and a wider back panel. Options:

• Order pre-cut panels from the same supplier as your original enclosure (recommended — they use CNC cutting for precise dimensions)
• Cut yourself using a circular saw with a fine-tooth blade for acrylic, or a jigsaw for polycarbonate
• Use a local acrylic shop — bring your stock panel as a template

Step 4: Disassemble the Top Hat

This is the most labour-intensive step. Remove the top panel, back panel, and side panels from the top hat. Label each panel with masking tape so you know which is which for reassembly. Remove the top hat frame extrusions from the corner brackets. Set aside the corner brackets — they'll be reused.

Step 5: Install New Extrusions

Insert T-nuts into the new, longer vertical extrusions. Attach the corner brackets at both ends. Mount the extrusions to the main frame using the corner brackets at the bottom, and connect the top frame (the square/rectangular loop that holds the top panel) at the top. Use a square to ensure the top hat is perpendicular to the main frame.

Step 6: Replace Z-Axis Belts (V2.4)

The V2.4 uses GT2 belts for Z-axis movement. Stock Z belt length for a V2.4 300mm is about 1,250mm per belt (4 belts total). For a 60mm extension, you need 1,370mm per belt. For 100mm, 1,450mm. Remove the old belts from the Z pulleys and tensioners. Thread the new belts through the same path — from the Z motor pulley, down to the bottom idler, up to the Z carriage, across to the other side, down to the bottom idler, and back to the tensioner. Reset belt tension using the standard Voron procedure (200-220Hz belt frequency).

Step 7: Replace Lead Screws (Trident)

Trident uses T8 lead screws (4-start, 2mm lead, 8mm pitch). Stock length for 300mm build is ~350mm. For a 60mm extension, order 410mm lead screws. Remove the Z motor from the mount, slide out the old lead screw, install the new one with the POM nut, and re-mount the motor. You'll need to re-level the bed after this change.

Step 8: Extend Z Cable Chain

Add links to the Z-axis cable chain to accommodate the longer travel. If your extension is 60mm, add enough links to give an extra 80-100mm of chain length (a bit more than the extension for safety margin). Remove the chain from both ends, insert new links, and reattach. Check that the chain doesn't bind at either extreme of Z travel.

Step 9: Reinstall Panels and Seal

Install the back panel first, then the side panels, then the top panel. Use the same screws and panel clips as the original. Apply closed-cell foam seal tape to all panel edges to maintain chamber temperature. A leaky top hat costs 5-10°C of chamber temperature and makes ABS/ASA printing harder.

Step 10: Update Klipper Configuration

The critical change is in your printer.cfg:

[stepper_z]
position_max: 360  # 300mm stock + 60mm extension
position_min: -5   # Same as stock (homing offset)
homing_speed: 5.0  # Keep stock

[stepper_z1]
# Same position_max as stepper_z
position_max: 360

[stepper_z2]
# V2.4 only — same position_max
position_max: 360

Also update any max_z_velocity and max_z_acceleration values if needed. Run Z_ENDSTOP_CALIBRATE to recalibrate your Z endstop position. Then run a full bed mesh and re-save your configuration.

Important: After increasing Z-height, you must also update your z_thermal_adjust section if you use it (the expansion coefficient calculation depends on total Z travel). Re-run the thermal calibration sequence.

Difficulty Level: Medium-Hard

The 60-100mm standard extension is a weekend project for an experienced Voron builder. Expect 4-8 hours of work depending on how carefully you disassemble and reassemble. The 120-200mm major extension is a significant project — more like a partial rebuild — and can take 10-15 hours.

Skills required: Frame assembly, belt cutting and tensioning (V2.4), lead screw installation (Trident), Klipper configuration editing, panel cutting (if doing it yourself).

Tools needed: Hex drivers (1.5mm, 2mm, 2.5mm, 3mm), small adjustable wrench, belt cutter or sharp scissors, measuring tape, square, panel cutting tools (if DIY).

Compatibility with Voron Models

Before vs After Benefits

The most tangible benefit is the ability to print tall objects in one piece. A 360mm Z-height fits most cosplay helmets (Mandalorian, Iron Man, etc.) without splitting. For functional parts, it means you can print full-length brackets, enclosures, and structural components without worrying about Z limits. The trade-offs — slightly longer heat-up time and marginally reduced rigidity — are acceptable for most users.

Critical Considerations Before Starting

• Workspace height: Measure your available vertical space. A V2.4 300mm with a 100mm top hat extension stands about 750-800mm tall (including the base). Make sure you have clearance for the top exhaust fan and filament path.
• Z-wobble risk: Taller Z-axis movement amplifies any lead screw or belt imperfections. If your stock printer already shows Z-banding, fix that before extending. Consider upgrading to anti-backlash lead screw nuts (Trident) or verifying belt tension and alignment (V2.4).
• Heated chamber volume: A taller enclosure has more air volume to heat. Your bed heater will take longer to bring the chamber to temperature. Consider adding a chamber heater for large extensions.
• Z-axis speed: With more Z travel, you might want to increase Z speed and acceleration to avoid slow prints. Update max_z_velocity (typically 15-20 mm/s) and max_z_acceleration (50-100 mm/s²) in Klipper.
• Panel sourcing: Pre-cut panels from the same supplier as your original build are always recommended. Mixed panel sources can result in slight colour or thickness mismatches.

Our Recommendation

For most Voron V2.4 and Trident owners, a 60-100mm extension is the sweet spot. It adds meaningful Z-height without the structural concerns of larger extensions. The cost ($76-130) is reasonable compared to the expanded capability, and the work is achievable over a weekend.

The V2.4 is the best platform for this mod because Z-belt replacement is simpler than lead screw replacement, and the kinematic design handles the extra height well. Trident owners should budget for good quality lead screws (POM anti-backlash nuts recommended) to minimize Z-wobble at the new extended height.