LOWRIDER V4 REMOVABLE DATUM RAIL — FULL-SIZE CUT PACKAGE
Revision: 2026-09-27
Units: inches. Geometry is 1:1. Never scale the DXF.

CONTENTS
- front-y0-rail-49in.dxf: 49.000 x 1.500 in. front rail; top-face lap layer.
- left-x0-rail-97in.dxf: 97.000 x 1.500 in. left rail; flip-face lap layer.
- datum-rail-full-size-layout.dxf: both full-size profiles and notes.
- MOUNT-AND-VERIFY.txt: installation and X0/Y0 verification procedure.

MATERIAL
Use two straight, clear hard-maple 1 x 2 x 10 ft boards, one per rail. Joint and
plane each blank to a finished 0.750 in. thickness x 1.500 in. width before cutting.
Orient the straightest, cleanest edge toward the work area; that edge becomes the datum.

FINISHED PARTS
- Front / Y0 rail: 49.000 x 1.500 x 0.750 in.
- Left / X0 rail: 97.000 x 1.500 x 0.750 in.
- Corner: 1.500 x 1.500 in. half-lap, 0.375 in. deep in each rail.
The front rail's lap is cut from its top face. Flip the left rail and cut its lap from
the opposite face. Dry-fit: top faces flush, no step at either inside working edge.

DXF LAYERS
CUT_PROFILE       Finished perimeter; profile only if the blank is intentionally oversize.
LAP_POCKET_TOP    Front-rail pocket, 0.375 in. finished depth from the top face.
LAP_POCKET_FLIP   Left-rail pocket, cut after flipping the blank, 0.375 in. finished depth.
REFERENCE         Dimension references only; do not toolpath.
NOTES             Text only; do not toolpath.

ROUTER BIT SPECIFICATIONS
Primary pocketing bit:
- 1/4 in. solid-carbide, two-flute upcut spiral; 1/4 in. shank.
- Cutting length at least 3/4 in.; center-cutting geometry.
- Use for the two 3/8-in.-deep half-lap pockets. The upcut clears hard-maple chips.

Optional profile bit (only if blanks are oversize):
- 1/4 in. solid-carbide compression spiral; 1/4 in. shank.
- Cutting length at least 3/4 in. and compatible with the router/collet.
- Leave both inside datum faces crisp; ease only non-registering edges by hand.

Conservative starting values — defer to the bit maker and prove on maple scrap:
- 18,000 rpm; 70–90 in./min feed; 18–25 in./min plunge.
- Pocket depth per pass: 0.100–0.125 in.; stepover: 35–40 percent of diameter.
- Profile depth per pass: no more than 0.250 in.; leave 0.010 in. radial stock, then
  take one full-depth finish pass if the machine and workholding are rigid enough.
- Use dust collection and pause if chips become dust, the maple burns, or the bit chatters.

CUT ORDER
1. Mill and measure both blanks. Enter the measured thickness in CAM.
2. Clamp the blank outside every toolpath; keep clamps beyond gantry and dust-shoe travel.
3. Cut the half-lap first. Verify 0.375 in. depth with calipers before releasing the blank.
4. Profile to length/width only when required. Tabs or a secured wasteboard are mandatory.
5. For the 97 in. rail, use an indexed/tiled operation if usable X travel is under 97 in.;
   keep one straight datum edge against a fence and verify index-pin spacing on scrap.
6. Dry-fit the corner and confirm the two top faces are flush and the inside edges meet.
7. Do not round over, sand, or chamfer either inside working face.

IMPORTANT
No mounting holes are included. Their positions depend on the as-built T-tracks,
torsion-box ribs, clamps, dust shoe, and LowRider cutter envelope. Follow the included
mounting procedure only after a powered-off and raised-Z clearance sweep.
