Vertical control points are surveyed reference points placed on walls and columns instead of the floor. They let the FieldPrinter station and print accurately on jobsites where floor control is impractical or where the surveyor works from vertical surfaces — common in data centers, distribution centers, and manufacturing plants.

The one thing that makes vertical control different from floor control: the laser tracker measures to the center of the reflector sphere, not to the marked point on the wall. Because the reflector sits a fixed distance off the wall, the surveyed coordinates must be shifted by that offset before printing. This guide explains how that offset works and how to apply it.

How Vertical Control Works

The FieldPrinter stations using a laser tracker and a spherical reflector (SMR). Unlike a total station, which can measure directly to a wall surface, the laser tracker measures to the center of the reflector sphere.

Because of that geometry:

• The reflector's center sits a fixed distance — 1-1/4" for Dusty's vertical control target — off the point marked on the wall.
• The surveyed control point coordinates must be shifted by that same 1-1/4", in the correct direction, so the data matches where the tracker actually measures.

If the offset is not applied, every vertical control point is off by 1-1/4", and the layout will not station correctly. Applying the offset is the core of the vertical control workflow — it is not optional.

Dusty's Vertical Control Target

To make this repeatable, Dusty provides a purpose-built, 3D-printed vertical control target (reflector nest):

• Holds the reflector in a repeatable, accurate position on the wall or column.
• Lightweight and low-cost.
• Built with the correct 1-1/4" offset, so the standoff distance is known and consistent for every point.

Using the same target for both the survey and FieldPrinter operation is what keeps the 1-1/4" offset consistent from point to point.

How to Apply the Offset

Apply the 1-1/4" offset one of two ways. Do this once, before printing — never both.

Option 1: Edit the CSV directly

Add or subtract 1-1/4" from the X and/or Y coordinate of each control point, depending on which way the reflector faces and how the layout's coordinate system is oriented.

Example: The CSV holds the coordinates of the points on the wall, but the reflector center is 1-1/4" off the wall in the Y direction. Add 1-1/4" to the Y coordinate of each point.

Option 2: Shift the points in CAD

Move the control points by 1-1/4" in your CAD file before exporting the CSV. This is often less error-prone than editing the CSV by hand. You can use Dusty's LSP commands, Autodesk Point Layout, or native AutoCAD commands (Insert Multiple Points, MOVE, and DATAEXTRACTION).

Placement and Recording

Vertical control points follow the same placement and stationing rules as floor control:

• Record 3 or more control points per station (minimum 3 non-collinear). More points improve best-fit accuracy and keep the layout consistent between stationings.
• Spread the points around the print area so they enclose what you're printing.
• Confirm the CSV includes X, Y, and Z coordinates and that the units match the layout file (feet, inches, or meters).

For general stationing and error-review guidance, see the related articles below — this article covers only what's unique to vertical control.

Best Practices

• Place targets on stable, permanent surfaces — concrete walls or structural columns, not temporary or movable objects.
• Label and protect the targets so they stay usable and undisturbed for the whole project.
• Double-check the offset was applied correctly before printing. This is the most common source of error in vertical control.
• Coordinate with your surveyor on which reflector and target are used, so the survey and FieldPrinter operation match.

Related Articles

• What Are Control (Surveyed/Datum) Points and Why Dusty Needs Them
• How to Use the Control Point Target to Place the Reflector on a Control Point
• Importing and Managing Control Points (CSV)
• How to Export Points from AutoCAD to a CSV and Import Points from Excel or Google Sheets into AutoCAD

{{REVIEW}} flags for Daniel

1. {{REVIEW: Reflector diameter}} — The live article states a "1.5" SMR reflector, like-for-like" requirement. The source doc does not state a reflector diameter; it only specifies the 1-1/4" standoff offset and Dusty's vertical control target. I removed the 1.5" claim. Confirm the correct reflector spec (and whether a specific diameter must be called out).
2. {{REVIEW: Offset value is fixed?}} — The source doc says the reflector center sits "for example, 1-1/4"" off the wall, but also that Dusty's target has "the correct 1-1/4" offset built in." I've stated 1-1/4" as fixed for Dusty's target. Confirm the offset is always 1-1/4" for the Dusty vertical control target (vs. varying by reflector/nest).
3. {{REVIEW: Vertical control target availability}} — The source doc describes the 3D-printed vertical control target as "developed." Confirm it is generally available to customers (not beta/limited) before this stays in a public article.
4. {{REVIEW: Permission group / visibility mapping}} — This is a data/documentation inconsistency, not an article issue. The live article 46323573230619 has permission_group_id = 50440584268059, which PLAYBOOK §1 labels "internal." But its user_segment_id is NULL, meaning it is visible to everyone (public) in Zendesk. 126 of 131 published articles have user_segment_id = NULL; only 5 are segment-restricted (40785489129627). permission_group_id is Zendesk's edit-permission group, not viewer visibility. The playbook's public/internal mapping keys off the wrong field. I set this draft to public because the article is already customer-visible and you chose public scope — but the playbook §1/§4/§5 mapping should be corrected to use user_segment_id.
5. {{REVIEW: vertical_control label}} — I reused control_points, stationing, control_point_accuracy (confirmed in use across the Control & Stationing section). I did not pull the full live label set this session, so I did not coin a vertical_control label. If none exists and you want one, that's the single new label §2 would allow for this article.