3xD 1.0-rc2 release notes

← All release notes

10 November 2026 · Release candidate · Pending approval

3xD 1.0-rc2 brings the current car parts together into complete, versioned inventories for the 3 mm GRP and 4 mm printed chassis. It replaces the partial 1.0-rc1 packs with a complete set of selected parts, options, hardware lists and validation records.

This is a development release candidate. Full assembled fit and running validation are still pending. Publishing these notes does not mark the design as production approved.

Previous release: 1.0-rc1 describes the design changes from OpenMini v1. Rc2 builds on that design by completing the release packaging and documentation.

Subsequent update: 1.1-rc1 provides wider lower side-spring pockets as replacement rails for this baseline.

What changed from rc1 to rc2?

This is a packaging and documentation update: there is no new geometry change from 1.0-rc1. Both chassis variants now have their own complete inventory, with exact file hashes and quantities for one car. The earlier 1.0-rc1 changed-part packs are superseded.

What’s in each pack?

  • 45 distinct STL files per chassis setup, covering required parts, optional matched front arms and upper braces, and ride-height shims.
  • 46 required part instances per car, including two bearing inserts whose physical fit is still pending. Optional alternatives and shim stock are additional; do not fit every alternative.
  • PARTS.csv with per-car quantities, plus REQUIRED_HARDWARE.txt for purchased components and unresolved measured stacks.
  • MANIFEST.json, package checksums and validation evidence for traceable part selection.
  • Cutting DXFs for the sheet parts. DXFs show flat profiles; use the STL files and notes for underside 90° countersinks.

Choose the matching chassis setup

GRP · 3 mm chassis

Sheet-part STL references and cutting DXFs, with the matching GRP bumper and pod geometry. Use the GRP-specific reversible 45/46 bearing inserts.

Printed · 4 mm chassis

A 4 mm printed chassis and 3 mm pod plate, with the matching printed-chassis bumper and pod geometry. Use the dedicated 45 4C bearing inserts; these are not the GRP reversible inserts.

Keep the setup-specific chassis, bumper, pod and bearing parts together. The shared version number does not make every part interchangeable. Both setups use the default 4-1 front-arm selection.

Current design selections

The complete packs carry forward these selections from the current baseline:

  • Centred front-arm bosses and the 1.5 mm rearward kingpin correction; default arms are 4-1.
  • 3.3 mm mounting clearances, with direct-thread pilots unchanged.
  • Two 1.5 mm spacers for the rear-facing M3 servo-saver ball studs.
  • The original, unreinforced A1 pod-pivot retainer with M3 × 6 fixing.
  • The owner-selected P2 spring cups and continuous side-spring brace.
  • The rear guide with a 7.0 mm pocket, 5.8 mm hard bore and existing spring-lip cap.
  • Low rear-offset servo mounts and separate rear body supports.
  • A 75 mm-wide, 3 mm-thick pod plate with rear clearance notches.
  • The stepped honeycomb TPU bumper with 48 mm mounting centres.

Upgrading and reprinting

If you already have the current 1.0-rc1 geometry, rc2 itself requires no geometry-driven reprint. Use the complete rc2 inventory to check that your build has the correct parts and quantities.

For older builds, both front arms need the current centred-boss, rearward-kingpin revision. The matching upper brace and root tie can be reused for that arm change; separately check whether your parts need the M3 clearance update. Older mixed kits and sliced jobs can contain superseded parts. Re-slice the selected current STLs rather than reuse old G-code.

Validation and remaining checks

All 45 distinct STL selections in each setup were checked individually as closed, consistently wound single solids. A1 and P2 identities, archive checksums and inventories were also verified.

Bearing fit remains pending. The two required inserts are the current backed flanged trials in fit_pending_required/. A successful physical fit has not yet been confirmed. Check the real bearing flange seating and axle stack before treating them as final.

Rear upper spring-seat fit, full steering and suspension movement, screw engagement and running durability still need physical checks. Individual mesh validation does not establish assembled fit or race-rule compliance.

Printing notes

  • Follow the material and layer guidance in PARTS.csv. The supplied STLs are individual parts, not arranged print plates; no sliced 3MF or G-code is included.
  • Use PETG for the motor flange, pod sides and servo-saver spacers. Keep the TPU bumper on its own material plate and profile.
  • Use 0.08 mm layers for fine interface parts where specified. Ride-height shims use one 0.25 mm layer, including the first layer.
  • Servo-saver spacers use 0.10 mm layers including the first layer: 15 layers in total.
  • Inspect support placement. Keep support out of the A1 socket and clear of the P2 catch.

Version history

1.0-rc2 · 10 November 2026: complete current part inventory; pending approval.

1.0-rc1 · 10 November 2026: initial tracked baseline containing changed-part packs; superseded by rc2.

Future releases will have their own entry in the release notes archive, with changes, compatibility and validation status recorded for each version.