3D scanning in electric vehicle manufacturing: battery packs, castings, and lightweight structures

The Tesla Model 3 needed more than 170 individual pieces of stamped sheet metal and over 1,600 welds to build its rear underbody. The Model Y replaced that entire assembly with a single aluminum gigacasting. Other automakers have followed the same path for the same reason: fewer stamped parts, fewer welds, and a lighter structure.

That shift changes what shows up on the measurement bench. A traditional body shop scans stamped sheet metal and welded assemblies. An EV plant adds battery enclosures that double as structural and pressure-sealed components, single-piece aluminum castings the size of a dinner table or larger, aluminum extrusions standing in for parts that used to be steel stampings, and die-cast motor housings with cooling jackets that cannot leak. Each of those objects needs something different from a 3D scanner: coverage wide enough to hold flatness data across a meter-plus panel, volumetric accuracy that stays reliable across several meters of casting, or a probe and laser line that can actually reach into a 10 mm bolt hole.

Battery pack enclosures, structural castings, lightweight aluminum structures, and motor housings each need a different setup, and the sections below walk through why. SCANOLOGY, the industrial metrology brand of SCANTECH (Hangzhou) Co., Ltd., builds the systems covered below for exactly that range of parts.

Battery pack enclosures: sealing surfaces, hole patterns, and BMS fit

A battery pack enclosure is not one part but three that have to fit together dimensionally: the frame that carries the modules, the tray and cover that seal the whole assembly, and the mounting points for the battery management system (BMS). Cover and tray assemblies on a typical EV pack commonly run wider than 1.6 meters, which puts them well outside what a single scan from a stationary setup can capture without multiple repositions.

Each of those three parts carries a different inspection priority. On the frame, modules won't seat correctly unless installation holes, weld locations, and slots hold their position tolerances. On the cover and tray, profile, flatness, and parallelism take priority, since any high or low spot on the sealing face becomes a leak path once the gasket compresses. On the tray's mounting holes, position and diameter across a wide range of hole sizes need to stay in tolerance so the BMS bolts up without shimming.

For the frame and its hole patterns, SCANOLOGY's KSCAN-E wireless handheld scanner pairs an infrared large-area mode for covering the broad panel area with a dedicated deep-hole scanning mode for the installation holes themselves, reaching up to 8.29 million measurements per second at 0.020 mm accuracy.

For the full cover and tray, where the part is too wide for a handheld scanner to cover without losing registration accuracy, SCANOLOGY's TrackScan Sharp optical tracking system extends the measurement volume well past what a single handheld setup can hold, with the TrackScan Sharp-S configuration rated at 135 m³ of high-precision measurement volume, with volumetric accuracy from 0.048 mm at 10.4 m³ to 0.159 mm across the full 135 m³ range. That volume is what lets a technician capture a full battery tray in one tracked setup, with every point referenced to the same tracker position, rather than stitching together several handheld scans that each carry their own registration error.

Covers and trays are also frequently coated or painted on the sealing face, which rules out adhesive reference markers the same way a painted dashboard panel does in an automotive interior job. SCANOLOGY's NimbleTrack Gen2 scans without requiring targets fixed to the part, which keeps the sealing surface free of adhesive residue before the gasket goes on.

Once the scan data is captured, flatness, profile, and parallelism checks on the sealing faces run through DefinSight, SCANOLOGY's own scan-capture and metrology software platform, which is built to integrate with the KSCAN and TrackScan lines, among other SCANOLOGY scanners. That means a reviewer can check hole position from the KSCAN-E scan and sealing-face flatness from the TrackScan Sharp scan in the same software, rather than cross-referencing two scanner vendors' reporting tools by hand.

Structural castings and gigacasting: wall thickness and deformation

Gigacasting, also called megacasting, uses high-pressure die casting to produce a single large aluminum structure in place of dozens of stamped, welded, and bolted parts. Tesla's original underbody castings are commonly cited as replacing around 70 individual parts with one casting shot, and other automakers have adopted the same approach to cut part count, reduce the number of joints that need welding and sealing, and bring the structure's overall weight down.

That consolidation changes what a single rejected part costs. Large aluminum castings are prone to warping as they cool, and uneven wall thickness in a cast structure shows up as a weak point exactly where the vehicle's crash structure or battery mounting depends on it being uniform. On a casting that replaces 70 stamped parts, a wall-thickness defect in one section can scrap the entire structure rather than one small bracket. Both problems are normally checked the same way: scan the full casting, compare the point cloud to nominal CAD, and look at the resulting deviation map for wall sections that deviate from nominal or for twist across the part that would not be visible from measuring a few discrete points.

A case inspecting die-cast aluminum parts used in engine, door, hood, and trunk assemblies shows what that comparison is worth in practice: a full scan-to-CAD comparison on these smaller aluminum castings cut inspection and adjustment time from a full day to about an hour, with each part taking roughly 3 minutes to scan. That case used an earlier-generation SCANOLOGY SIMSCAN handheld scanner (750 g, since succeeded by the current SIMSCAN-S Gen2 and SIMSCAN-E Gen2 lineup) alongside DefinSight for the deviation reporting; SCANOLOGY's current palm-sized handheld, SIMSCAN-S Gen2, carries forward the same full-field comparison approach at 560 g and 0.015 mm accuracy.

A gigacasting runs the same deviation-mapping process at a much larger scale, often several meters across rather than the smaller castings in that case, which is where SCANOLOGY's tracking systems take over from a handheld scanner. TrackScan Sharp-S covers 135 m³ (volumetric accuracy 0.048 mm at 10.4 m³, 0.159 mm across the full range), large enough to capture a full-size underbody casting in one tracked setup, TrackScan Sharp-Z extends tracking to 12 m and 600 m³ per station for the largest structures, and NimbleTrack Gen2 adds marker-free scanning for the raw, unpainted casting surfaces that come straight out of the die, where a rough-cast finish makes adhesive targets harder to seat and keep in place.

Optical scanning and CT inspection catch different things on a casting this size. A full-field scan-to-CAD comparison is strong at finding external deformation, warping, and wall-thickness deviation that shows up as a surface-level change in geometry. It will not find subsurface porosity or an internal void sealed inside the casting wall, which is a job for X-ray or CT inspection instead. Most gigacasting quality programs run both: optical scanning for the geometry and CT or X-ray for what is happening inside the metal.

Lightweight structures: aluminum extrusions and structural members

Weight is the reason EVs are replacing stamped steel with aluminum in more places than body panels. Extruded aluminum profiles are showing up as crash rails, side sills, and battery enclosure frames because an extrusion can carry internal ribs and multiple wall sections in a shape a stamping press cannot produce in one pass, at a fraction of steel's weight.

Dajcor Aluminum, a Chatham, Ontario-based supplier of extruded and fabricated aluminum components to the automotive, aerospace, and construction sectors, faced a specific version of this measurement problem on its large extrusions, which run 2 to 4 meters long with cross-sections around 0.2 by 0.2 meters and deep internal channels, all held to a ±0.127 mm tolerance. Conventional probing on parts that size was slow, and temperature swings, vibration, and airflow on the shop floor made the job harder still.

Dajcor's solution combined SCANOLOGY's TrackScan Sharp-E optical scanning system for the extrusion's overall profile with the i-Probe 500 probe for the deep internal channels a laser line cannot see into directly, with both data sets brought together in PolyWorks Inspector for reporting. Every part measured this way met the ±0.127 mm tolerance, inspection ran about an hour per part, and the shop no longer needed the rigid clamping fixtures that probing alone had required. Because the i-Tracker keeps its own reference to the part independent of how the extrusion is clamped, a technician could scan one side, flip the part over, and pick up the second side under the same tracker reference instead of re-fixturing and re-zeroing the part.

An extruded battery enclosure frame or crash rail on an EV platform poses the same combination of a long, broad surface and tight internal channels, which is why the scan-plus-probe pairing from the Dajcor case transfers directly to that application.

E-motor housings: confined features on a pressure-sealed casting

An EV's drive motor housing is a die-cast aluminum part that has to do two things at once: keep its bearing bores concentric so the rotor spins true, and keep its integrated cooling jacket fully sealed under several bar of coolant pressure. Both requirements come down to the same kind of confined, feature-dense geometry that gives a bulky scanner trouble: bearing bores, bolt bosses, and cast cooling channels packed close together on a part that is itself fairly compact.

SCANOLOGY's SIMSCAN-S Gen2 targets exactly this kind of confined, feature-dense casting on other automotive parts: deep pockets and bolt bosses that a smaller, lighter scanner can angle into without losing line of sight. At 560 g with 0.015 mm accuracy and a dedicated deep-hole scanning mode, SIMSCAN-S Gen2 can reach a motor housing's bearing bore and cooling jacket features the way it already handles ports and ribs on an engine bracket, and the resulting scan compares against nominal CAD in DefinSight to flag bore position or wall-thickness deviation before the housing moves to final assembly.

One platform for every EV scan

Battery frames, gigacastings, extrusions, and motor housings each call for a different scanner, but they do not need to live in different software. DefinSight is built to integrate with SCANOLOGY's full range of industrial 3D scanners, including the KSCAN, SIMSCAN, TrackScan, and NimbleTrack lines, according to its current product page, so a battery frame scan from KSCAN-E and a tray scan from TrackScan Sharp can be reviewed in the same software rather than handed off between separate scanner vendors' reporting tools. For a quality team running all four part types through the same line, that means a consistent deviation report format and GD\&T workflow, regardless of which scanner captured a given part.

EV manufacturing scanner selection at a glance

Frequently asked questions

Can one SCANOLOGY system handle both a battery tray and a small die-cast bracket? Generally not with the same setup. A handheld scanner sized for a bracket's bolt bosses and ports loses accuracy and takes far more repositioning when stretched across a 1.6-meter tray, and a tracking system sized for the full tray is more hardware than a small bracket needs. KSCAN-E and SIMSCAN-S Gen2 cover the confined, high-accuracy features, while TrackScan Sharp and NimbleTrack Gen2 cover the larger tray, cover, and casting surfaces, and most battery programs keep both types on the line.

Does 3D scanning replace CT inspection for gigacastings? No. Optical 3D scanning compares the casting's external geometry to CAD and is strong at catching deformation and wall-thickness deviation from the outside. Internal porosity or hidden voids inside the casting wall require X-ray or CT inspection, and most gigacasting quality programs run both methods rather than one in place of the other.

Why does the battery tray case study use TrackScan Sharp instead of a handheld scanner alone? Battery trays and covers commonly exceed 1.6 meters in width, wider than a handheld scanner can cover accurately without multiple repositioning steps that risk alignment drift. TrackScan Sharp's larger measurement volume captures the full part in one tracked setup instead.

Is NimbleTrack Gen2 only useful for marker-free scanning? Marker-free capture is its most relevant feature for painted battery covers and raw cast surfaces, but the underlying system is a full wireless tracking scanner, with tracking distances up to 4.2 meters on the E variant and 6.63 million measurements per second. Those numbers matter independently of whether a given job needs marker-free scanning.

What tolerance can SCANOLOGY systems hold on a multi-meter aluminum extrusion? In the Dajcor Aluminum case, TrackScan Sharp-E paired with the i-Probe 500 held a ±0.127 mm tolerance on extrusions 2 to 4 meters long with deep internal channels, with every part in the case meeting that tolerance.

EV platforms keep adding new categories of parts that did not exist on an internal combustion line: structural battery enclosures, single-piece castings the size of a workbench, extruded aluminum crash structures, and pressure-sealed motor housings. Each one has a different combination of size, accuracy requirement, and surface condition, which is why the fit comes down to matching system to geometry: KSCAN-E and SIMSCAN-S Gen2 for the confined, high-accuracy features, TrackScan Sharp and NimbleTrack Gen2 for the room-scale castings and trays, with DefinSight tying the resulting scan data together so a reviewer isn't reconciling four scanners' worth of exports by hand.