If Not 6D, Then What’s the Point?

Let’s be blunt — the era of quoting a single-axis repeatability number and calling it “precision” is over. If your motion system can’t account for — and control — all six degrees of freedom, then you’re not working with precision. You’re working with assumptions.

At ALIO Industries, we’ve never been interested in “good enough.” And our customers haven’t either. That’s why we talk about Customer Driven Precision — a mindset that demands real, measurable, and application-relevant performance, not marketing theatre. We’re pushing the conversation forward — past outdated test methods, past hollow claims, and straight into the heart of true nanometer-level capability. Because in modern manufacturing, accuracy without full transparency is just performance art. And the show’s getting old.

For years, motion systems have leaned on the crutch of “plane repeatability” — measuring linear displacement along an axis and pretending everything else just magically holds still. This worked fine when tolerances were loose and nanometers were science fiction. But welcome to today, where errors in pitch, yaw, roll, and straightness can’t be swept under the rug. Not if you care about performance. Not if you’re building real technology.

Here’s the uncomfortable truth. Your stage doesn’t move in a straight line. It twists, bends, and dances through 3D space — and every one of those deviations impacts your results. If your motion system ignores those errors, it’s not high-precision — it’s high-hope.

Precision manufacturing doesn’t happen in 1D or 3D. It happens in 6D — three linear axes and three rotational ones, all interacting simultaneously. That’s why ALIO pioneered 6D Point Precision® — a radical shift away from simplistic linear specs and toward holistic, high-resolution, all-axis performance metrics.

And that shift recently became official. As of August 2023, ALIO’s approach is no longer just innovative — it’s foundational. The American Society of Mechanical Engineers (ASME) published B5.64, a new standard for evaluating precision motion systems, that formally recognizes the 6D methodology ALIO has championed for more than a decade. The standard validates what we’ve always known, that measuring only a single axis of motion — assuming perfect linearity — is misleading. Real systems move in space. Real precision accounts for all six degrees of error.

Our approach starts by recognizing the motion stage for what it really is, a platform where every point in space moves in a spherical repeatability zone, influenced by all six degrees of error. We quantify that — not just on one axis, but across the entire motion path. Why? Because anything less is just guessing.

The publication of ASME B5.64 confirms that the industry is finally catching up to what Customer Driven Precision requires, test methods that align with the reality of how motion systems behave — especially when accuracy must be validated at the sub-micron or nanometer levels. And while others are now scrambling to meet this bar, ALIO customers already benefit from motion systems engineered and validated using this gold standard.

In semiconductor metrology, photonics alignment, medical device manufacturing, and aerospace applications, every micron matters — and so does the confidence behind it. Engineers are being asked to design tighter, faster, and more complex systems than ever before. But if the motion foundation isn’t stable in all six degrees of freedom, everything built on top is compromised.

And here’s the kicker. It’s not that 6D motion is the future. It’s that it’s the only way forward for industries pushing the boundaries of what’s possible. ALIO’s 6D Point Precision® methodology — now echoed in international standards — gives customers something they’ve always deserved, truth in motion.

The motion control industry now has a choice. Keep hiding behind oversimplified specs or embrace the full reality of precision. ALIO chooses the latter. We always have. Because if you can’t measure all six degrees of error, you can’t control them. And if you can’t control them, what’s the point of calling it precision at all?