LowRider v4 mobile cradle + datum rail — 4x8 sheet CNC nest
Concept nest, not a released fabrication drawing
Revised 2026-09-27: added removable hard-maple X0/Y0 datum-rail profiles and joint details.

File: cradle-nest-4x8.dxf (DXF R12; imports into Estlcam)
Units: inches

PLYWOOD NEST
Three 96 x 48 in. sheet layouts are arranged side by side along X (long axis = X).
Each sheet carries:
  - TWO rounded-triangle end-frame layers, 56 in. base x 40 in. tall, with 3 in.
    fillets and an inner weight-relief cutout. One layer is upright and one flipped;
    the pair fits in 87 x 40 in.
  - Two 6 x 6 in. caster/bearing pads and two 4 x 4 in. leveler blocks
  - Two additional 6 x 6 in. spare pads in the top band
Three sheets yield all six triangle layers, 12 pads, and six leveler blocks.

HARD-MAPLE DATUM RAIL — SEPARATE STOCK, NOT PLYWOOD
Buy two straight, clear 1 x 2 x 10 ft hard-maple boards. Mill both to a finished
3/4 x 1-1/2 in. section, then cut:
  - FRONT / Y0 rail: 49 x 1-1/2 x 3/4 in.
  - LEFT / X0 rail: 97 x 1-1/2 x 3/4 in.
The DXF places both full-size rail outlines beyond the three plywood sheet boundaries on
the DATUM_RAIL layer. They are cutting/template references for the separate maple stock;
do not include them in a plywood-sheet toolpath. DATUM_GRAIN marks grain direction.

CORNER JOINT
Cut a 1-1/2 x 1-1/2 in. half-lap at the front-left mating end of EACH rail, 3/8 in.
deep in each piece and on opposite faces. The assembled top faces must be flush. The
front rail's inside face establishes Y0, the left rail's inside face establishes X0,
and their inside-face intersection is X0/Y0. Joint details are full-size on DATUM_LAP.
Joint or CNC-trim the two inside reference edges dead straight. Keep those edges crisp.

MOUNTING HOLD
No datum-rail mounting holes are drawn. Dry-fit and sweep the LowRider carriage, router,
dust shoe, clamps, and cutter envelope first. Then transfer safe countersunk-hole locations
that avoid T-tracks and torsion-box ribs. Mount into replaceable inserts so both rails can
be removed and reinstalled repeatably. Set them only slightly proud of the MDF.

SPINE
Purchased 2 x 6 LSL, 1-3/4 x 5-1/2 in., cut to exactly 120 in. It is not in this nest.

DXF LAYERS
  CUT_PROFILE  — plywood through-cuts
  DRILL_HOLD   — placeholder pivot bore and flange pattern; DO NOT CUT yet
  SHEET_REF    — plywood sheet boundaries; reference only
  DATUM_RAIL   — full-size hardwood rail profiles; separate stock
  DATUM_LAP    — full-size half-lap boundaries; 3/8 in. depth
  DATUM_GRAIN  — maple grain-direction references
  DATUM_NOTE   — dimensions and fabrication notes; do not cut

PLYWOOD CUT PARAMETERS — STARTING POINT ONLY
1/4 in. compression or downcut bit; 1/4 in. depth per pass; about 100 in/min XY and
30 in/min plunge. Add four tabs per triangle and two per pad, or leave a 1/16 in. onion
skin. Cut inner reliefs before outside profiles. Adjust feeds and toolpaths for your bit.

REQUIRED CHECKS
  1. Prove machine square and scale with a test square and coupon.
  2. Measure actual plywood and maple thickness before programming depths.
  3. Verify one triangle layer and the 62 in. footprint before cutting all layers.
  4. Do not cut DRILL_HOLD geometry until bearings and pivot engineering are released.
  5. Verify the proposed 49 x 97 in. support field and complete machine envelope before
     drilling the datum rails or treating the final rail height and offsets as released.
