NORTH POLE EXPRESS — REV B PRINT-FIRST FIT TESTS
PETG / confirmed 0.6 mm nozzle / geometry only; no machine profile or G-code.

Print in this order; there is no need to print every set immediately.

1. 01_SHORT_CLEARANCE_B.3mf — 3 female tracks + 1 common male handle.
   All tracks retain a REAL blind front cap: 35.0 mm total height, cavity ends
   at33.8 mm, cap1.2 mm. Male ends33.3 mm:0.5 mm axial running clearance.
   FT-S-0p15 =0.15 mm per mating face (red presentation color).
   FT-S-0p25 =0.25 mm per mating face (gold presentation color).
   FT-S-0p35 =0.35 mm per mating face (spruce presentation color).
   The tracks appear left-to-right in that order in the supplied layout.
   Mark each track's clearance on its outside before removing it from the
   plate. Object names and STL filenames also identify it. Colors are
   presentation metadata; one PETG color is sufficient for these tests.
   Insert the common male FORE/chamfered end into each track's open aft end.
   Check sliding, binding, surface damage and side play. Do not force a jam.

2. 02_FULL_LENGTH_TRACK_FIN_B.3mf —136.7 mm blind track and actualNP-06 fin.
   This supplied full-length female is the CURRENT0.25 mm-per-face default.
   If a different short coupon fits better, regenerate the full-length and
   main body interfaces before printing them; scaling parts changes other
   dimensions and is not a substitute for selecting interface clearance.
   Check the entire stroke for binding, bowing, front-cap sag or debris.
   This isolated track has less surrounding support than the full airframe;
   it is a useful process check, not a complete-body qualification.

3. 03_TAIL_KEEPER_FUNCTION_B.3mf —35 mm tail, real keeper,4 short shoe levers.
   Tail has four blind0.25 mm-per-face tracks, permanent gas-side walls and
   the actual two insert bosses. Short shoes have the actual72.5 mm tip
   radius to expose interface rocking, with economical8 mm-tall handles.
   Install2 purchased M3 heat-set inserts, assumed4.6 mmOD x4 mm length, in
   4.2 mm pilots5 mm deep. Verify the purchased insert dimensions and its
   maker's installation instructions before use. Printed pilot is a trial.
   Insert all4 shoes, then fit the keeper STRAIGHT onto the aft end. It does
   not rotate. Use2 M3x6 mm under-head thumb screws WITHOUT washers for the
   nominal stack; M3x8 screws can bottom in the blind bosses. HeadOD up to
   8 mm projects locally about0.2 mm beyond the nominal body radius.
   With keeper secured, check axial retention and visible tip movement.
   Nominal axial running clearance is0.5 mm; this is NOT a zero-play claim.
   Remove keeper and confirm every shoe can withdraw without damage.
   This short sample does not reproduce the full root's bending stiffness.
   Also assess the actual full-length fin locked in the final full-length
   body before accepting the joint for any build or flight.

ORIENTATION / PROCESS
   Use supplied3MF transforms: tracks/tail stand with their axes vertical;
   male shoes and the real fin stand root-down; keeper lies flat aft-face
   down. These match the main RevB orientations. Inspect previewed toolpaths
   for continuous1.2 mm cassette walls and a sound1.2 mm closed front cap.
   Brims may be needed, especially for the tall isolated track and fins.
   Keep supports out of the sliding channels. The blind-cap bridge and local
   fin shoulders still require process review. No printer profile is set.
   STL files use functional coordinates; use the3MF for arranged orientations.

LIMITS
   Mesh/fit diagnostics are digital designer checks. These samples do not
   establish airtightness, repeated-use durability, insert pullout strength,
   temperature capability, structural strength, stability or flight readiness.
   Record material/profile, chosen clearance, measured play and any damage.
