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FD/LAB · B07UNCLASSIFIED // BY-LINE: THE BENCHON THE LINE

LAB/NOTES

Bench-side scrawl, doctrine arguments, failure logs, and field debriefs. Pinned as the parts get built — published as written, edited only when the field draws a line through them.
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BENCH SURFACE · 09 NOTES
DESIGN
N-0092026.04.22

The duty-day toggle

How the site's light-mode palette works, why it is an opt-in rather than a system preference follow, and what the name means.
WEB
FD
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DESIGN
N-0082026.04.15

The hardware standard

Why Keystone commits to a public hardware family and what that means for repair in the field.
DESIGNKEYSTONE
FD
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DESIGN
N-0072026.04.08

Power budget: HMD-1

How the Sentinel HMD-1 power architecture is being sized, and why the constraints are harder than they look.
ARCHSENTINEL
FD
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DESIGN
N-0062026.03.20

Webbing: the 25mm standard

Why Keystone uses 25mm MIL-spec webbing throughout, and what that choice rules in and out.
DESIGNKEYSTONE
FD
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DESIGN
N-0052026.03.18

Console UI: building the configuration interface

Design decisions behind the Sentinel HMD-1 web configuration console — local-first, single-file, 68KB uncompressed.
WEBSENTINEL
FD
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DESIGN
N-0042026.03.05

Sentinel architecture: single-cable decision

The reasoning behind collapsing power and data onto a single USB-C connection in the HMD-1 architecture — and the specific numbers that made it viable.
ARCHSENTINEL
FD
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FIELD
N-0032026.03.01

Fourth-season design principles

What it means to design for the fourth season, and the constraints that follow from taking it seriously.
FIELDKEYSTONE
FD
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PROCESS
N-0022026.02.27

Keystone A03→A04: weight claim downgrade and what changed

A03 shipped with a 1,340g total weight TARGET. Physical build of A04 came in at 1,387g. This is what we changed and why we didn't fight it.
REVKEYSTONE
FD
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DESIGN
N-0012026.02.14

Keystone layout iteration: why the clamshell won

Three layout variants, two fabrication rounds, and the failure mode that settled the architecture.
DESIGNKEYSTONE
FD
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A question from the field. A correction. An argument.
Notes are published as written. If something is wrong, disagree, or worth following up on — the bench reads the inbox directly.
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FD/LAB-NOTES · MK4 · REV 2026◂ BACK TO HOMEFOUNDER-LED · BENCH NOTES