Compare · Method

The specs that decide
fidelity are the ones
almost nobody publishes.

Every motion platform datasheet gives you envelope and payload. Almost none give you transport delay with its measurement boundary, frequency response under load, or what the control-loop number actually refers to. This page is the table we wanted to find and could not.

The method

A number without a
measurement boundary
is not a specification.

"Sub-30 ms end-to-end" and "8 ms" are not comparable unless you know what each was measured between, under what payload, with what software in the chain. The same is true of a control-loop rate: 1 kHz can mean a command cadence, a servo loop, or a cueing-engine tick, and those are three different machines. So every row below carries a label — VENDOR for a published manufacturer figure, INTERNAL for one of ours, and "not published" where nobody states it at all.


Our own row first

Held to the standard we are asking for.

It would be cheap to demand disclosure from other manufacturers and not give our own. So this is our row, held to the same standard.

ARK PDK fidelity-critical specifications with disclosure status
SpecificationFigureBasis
Encoder resolution21-bit absolute, 2,097,152 positions per revolutionPublished, arithmetic checkable
Drive loop, per motor8 kHz / 125 µsINTERNAL — read from the drive firmware timer
Inverse kinematics3.3 kHzINTERNAL
Control loop1 kHz position commands over CAN at 2 MbaudINTERNAL — 1 ms period; the platform answers inside it
Transport delayUnder 1 ms — game telemetry in, motion outINTERNAL — boundary stated, which is the point
Frequency response under load629 Hz, measured, with up to 250 kg on board · each motor reproduces up to 2,000 HzMeasured on the rig, payload stated
Motion envelopeNominal (single-axis) onlyOn the technology page, from the T1 firmware boot banner.
How we know this
  • 8 kHz drive loop, from the firmware timer configuration ARK drive firmware source
  • 629 Hz measured on the rig with up to 250 kg on board; up to 2,000 Hz reproducible per motor ARK engineering record, 2026-09-26 · payload boundary stated 2026-09-27
  • 3.3 kHz inverse kinematics; 1 kHz commands with per-command encoder return ARK engineering record
  • Under 1 ms is the game-to-motion figure, from the game's telemetry reaching the platform to the actuator moving; position commands run at 1 kHz inside it ARK rate definitions · /technology/latency/

Our transport-delay row states a boundary because that is what this page asks of everyone else: under 1 ms from the game's telemetry reaching the platform to the actuator moving, set out on the latency page. A figure of 1.4 ms has circulated for this platform; it is superseded and not repeated here.

What to ask any vendor

Four questions, including of us.

These are the questions that separate a specification from a headline. They work on any manufacturer in this category.

Between which two points?

A latency figure needs a start and an end. Ours starts when the game's telemetry reaches the platform and ends when the actuator moves. Ask every vendor for both points, and compare only figures that share them.

Under what payload?

Frequency response and acceleration figures measured on an unloaded platform tell you very little about the platform with a person and a cockpit on it.

What does the loop rate refer to?

A command cadence, a servo loop and a cueing-engine tick are all quoted as "control rate". Ask which one, and what the others are.

Is there a published method?

A number with a test method and a report behind it is a specification. A number on its own is a claim.

Ask us these and the answers are on this page. Where a figure is not published, the row says so.

Keep reading

Latency

Our own transport-delay account, in full, including the figure we withdrew.

Academic research

A protocol for measuring our latency independently, with no result claimed for it.

Every build starts with this platform. The PDK + ARK Ecosystem finishes it — racing chassis, wheelbase, wheel, load-cell pedals and button box, $8,499.99.

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