Machine control, takeoff and drone data education and news.

Why Subgrade Machine Control Models May Not Be the Best Choice for Your Project

Most contractors default to subgrade models without thinking twice. After building 20,000+ GPS models, our team has learned that's usually the wrong call. Subgrade offsets create plan mismatches, slow revision turnaround, and add cost without much upside. Finish grade matches what's on the plans and keeps your crew and PM on the same page. Here's when subgrade actually makes sense.

Zach Pieper

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Infographic showing 4 GPS site control principles for machine control: use the design engineer's surveyor, surround the site with control points, calibrate to 5 or more points, and trust but verify with daily checks.

Get Your 3D Grading Under Control: 4 Site Control Principles Every GPS Contractor Needs to Know

Poor site control is the number one problem we see from contractors running GPS machine control. Not bad models or broken equipment. Site control, the first step on every single project. We've seen it cost contractors two weeks of production, turn a correct machine control model on a balanced site into a mysterious site export, and force concrete footings to be redone because the control was rotated 2.8 degrees. Every one of those situations was avoidable.

A screenshot from a drone flight planning interface titled “DJI Mavic 3E Flight Planning for Topographic Survey Mapping” shows a mapped area with a green grid overlay and waypoint markers on the left. On the right, advanced settings display sliders for side overlap ratio (80%), frontal overlap ratio (80%), and margin distance. A note emphasizes that 80% overlap provides good photogrammetry results and should not be set below 70% for 3D mapping. A YouTube play button is centered over the image.

Quantum Flight Pack - DJI Mavic 3E Training Hub

If you're running a DJI Mavic 3E on a construction site, this is where to start. These training videos cover flight planning, RTK setup, camera settings, and calibration — everything you need to get clean topo data that works with your GPS machine control system.