Assembled CAD render of North Pole Express with red and ivory peppermint stripes, green evergreen fins and gold accents; Revision B prototype

Assembled CAD render, not a photograph. The assembled reference is for viewing, not a one-piece print.

Free Download / Seasonal rocket project

North Pole Express

A Christmas-themed, approximately 24-inch model rocket with raised peppermint stripes, sculpted evergreen fins, gold accents and removable fins on hidden internal T-track mounts.

About 24 inches tall
PETG / 0.6 mm nozzle
Removable fins

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ZIP · 40.9 MB · No checkout or email required.

Digital download. No physical item is shipped.

Start with the small fit test ↓

Exploded CAD render showing a removable evergreen fin, hidden T-track mount and separate rear keeper — Exploded CAD render of the Revision B mechanism. Physical fit remains unverified.

A closer look

Slide in. Retain at the tail.

The sculpted evergreen fins use hidden internal T-track mounts. Each fin slides in from the tail; a removable rear keeper blocks it from sliding back out.

Keep the fin shoes and tracks free of adhesive.
Slide each fin forward into its internal track.
Fit the rear keeper straight onto the tail and secure it with the specified purchased hardware.

To remove a fin, remove the keeper and slide the fin straight aft. Follow the included instructions and complete the fit tests before committing to a full print.

Optional fillers cover the tracks for display without fins. Fillers are for display only.

Inside the free package

North_Pole_Express_24_ALL_PARTS_B.3mf — 14 separate printable parts
REFERENCE_ONLY/North_Pole_Express_24_ASSEMBLED_B.3mf — assembled multipart reference
FIT_TESTS/ — three fin-fit test sets and PRINT_FIRST_README.txt
DISPLAY_ONLY/North_Pole_Express_DISPLAY_FILLERS_B.3mf — optional display fillers
READ_ME_FIRST.txt and REMOVABLE_FIN_INTERFACE.txt
PREVIEWS/ and REVIEWS/ — CAD renders and review notes
CHECKSUMS_SHA256.json

Printable layout: open North_Pole_Express_24_ALL_PARTS_B.3mf for the 14 separate printable parts.

Assembly reference only: REFERENCE_ONLY/North_Pole_Express_24_ASSEMBLED_B.3mf shows those parts assembled. Do not print it as a single object.

CAD preview of the separate North Pole Express body sections, nose, fins, rings and keeper — Separate-parts CAD preview. Use the ALL_PARTS 3MF for the printable layout and orientations.

The original ZIP and its instructions are supplied unchanged.

Print this first

Small test. Then the full build.

Short clearance test
Start with FIT_TESTS/01_SHORT_CLEARANCE_B.3mf. Compare the 0.15, 0.25 and 0.35 mm clearances using one PETG color. Follow FIT_TESTS/PRINT_FIRST_README.txt.
Full-length sliding test
Use FIT_TESTS/02_FULL_LENGTH_TRACK_FIN_B.3mf to check the actual fin and full-length track for binding.
Rear keeper test
Use FIT_TESTS/03_TAIL_KEEPER_FUNCTION_B.3mf to check the keeper and purchased insert/screw fit. Then assess the full fin locked into the full body.

If another clearance fits better, the matching interfaces need to be regenerated consistently. Scaling the fin or tube is not a substitute.

Dimensions: 612.4 mm (about 24.1 inches) tall including the keeper, before motor or screw-head projections; 145 mm fin span; 45 mm nominal body diameter plus raised decoration.
Build volume: The supplied printable layout fits the declared 230 × 250 × 250 mm envelope. Allow room for brims, supports and any multicolor purge arrangements in your slicer.
Material & nozzle: Designed around PETG and a 0.6 mm nozzle. Your filament, profile and physical fit still need verification.
Slicing: Geometry files only: no configured printer profile or ready-to-run G-code. Inspect every sliced part. Render colors are presentation metadata, not configured filament or AMS assignments.
Orientation & supports: Use the supplied printable 3MF orientations. Inspect thin features and closed track-cap bridges; brims or supports may be needed. Keep supports out of the sliding channels.
Purchased parts: Purchased parts are required, including a paper motor tube, retention hardware, M3 heat-set inserts and screws, recovery components and adhesives. Follow the supplied instructions and verify actual hardware dimensions.

Package notes & support

Version: Revision B — Prototype · November 2, 2026.

No usage license is specified in the supplied package. Contact ITERA if you need clarification about permissions; this listing does not add license terms.

For help, email info@iterarocketry.com with North Pole Express Revision B, your printer, material, slicer settings and photos. No order number is needed for this direct download.

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SHA-256

3618366d2b0c55e928759bca7d19c18a9ba47ec32d32ee1baa7deb4062051c37

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