In robotics integration circles, there’s a “heartbreaking story” circulating:

A certain integrator has made a big splash in the 3C electronics industry, having processed dozens of middle-frame polishing lines for a well-known smartphone brand. The precision is at the micrometer level, and the surface finish is mirror-like.

Later, they thought to themselves, “I’ve already mastered such intricate work—why not go on to grind a few automotive die-cast parts or even manhole covers? Wouldn’t that be like leveling the playing field?”

So, they confidently took on a project to deburr castings, simply transplanting the 3C solution directly over.

What’s the result?

The scene was utterly heartbreaking: the main spindle kept triggering overload alarms, the flexible floating head simply couldn't cut through the large burrs at all, and dust had completely clogged up the sensors. In the end, project acceptance seemed hopeless, and hundreds of thousands of dollars were wasted in vain.

This brings us to the hardcore topic we’re going to talk about today:

Why can’t the polishing solutions used in the 3C industry be directly applied to the casting industry?

This is absolutely not a “dimensionality reduction strike”—these are two completely different species.

Consistency of incoming materials: one is a “clone,” the other is a “blind box.”

3C industry The workpieces to be polished—such as phone cases and tablet back covers—are typically already subjected to high-precision CNC machining before entering the polishing station.

Feature: Dimensional tolerances are typically controlled within. ±0.05 mm Within.

Logic: Robots don’t even need particularly sophisticated visual positioning—simply following a pre-programmed path with their eyes closed can get them pretty much spot-on.

Foundry industry The workpieces—such as engine cylinder blocks, steering knuckles, and valve bodies—are “rough castings” just out of the sand molds or dies.

Feature: Flash (burrs) are random! In some areas, the thickness is 1 mm, while in others it’s 5 mm; some areas have nodules, while others have defects. Coupled with deformation after heat treatment, tolerances can reach as high as... ±2mm or even more 。

Logic: If you use the 3C “dead trajectory” method to grind castings, there are only two possible outcomes: either... Can't grind it. (The burr hasn't been cut off), or else... Collision machine (The burr was too hard—it actually chipped the tip of the knife.)

3C grinding is “fine-tuning”—a subtractive process performed on a defined reference point; casting grinding, on the other hand, is “land clearing”—a demolition effort carried out on uncertain terrain.

3C grinding The core demands are “shape preservation” and “appearance.”

It requires that the workpiece’s original curvature must not be altered and that there must be no scratches. Therefore, 3C solutions are typically equipped with: High-sensitivity, small-stroke pneumatic/electric floating spindle 。

Force Control Logic: Like a human hand gently caressing—apply just the right amount of pressure, and follow the natural flow.

Casting and grinding The core demands are “eliminating quantity” and “efficiency.”

Those thick parting lines and sprue systems aren’t “felt” at all—they’re literally “cut” right through! What happens when the soft, floating spindle used in 3C machining encounters large flash on a casting?

The cutting tool will “give way”!

Because the float is too sensitive, as soon as the blade touches a hard bone, it automatically retracts, eventually just gliding over the edge without making any cut at all.

The casting industry needs high-power electric spindles plus a more rigid force-control system. (Sometimes, there’s no need for floating at all—direct rigid cutting will do just fine.) Taking an embroidery needle to chop down a tree—that’s simply the wrong approach.

The harshness of the environment: greenhouse flowers vs. survival in the wild

3C Workshop What kind of environment is it? It’s a constant-temperature, constant-humidity environment—possibly even a dust-free cleanroom. The floor is spotless, and the equipment is impeccably clean.

Foundry workshop What kind of environment is it? It’s a true “industrial hell.”

Dust: Conductive metal dust is flying everywhere.

Temperature: In summer, temperatures can soar to 40℃+ .

Oil stain: Cutting fluids and mold release agents are everywhere.

In the 3C industry, robots and peripheral equipment often have insufficient protection ratings (IP). If precision force sensors and vision cameras are simply placed in a casting workshop, they’ll be rendered useless within a month—either due to dust entering their interiors and causing short circuits, or because their lenses become coated with oil and grime.

Equipment in the casting industry must be “durable.” Explosion-proof design, positive-pressure protection, and specialized sealing structures—while these may be optional in the 3C industry, they are essential safety features in the casting industry.

From 3C to casting, it may seem like everything revolves around “robots + grinding heads,” but in reality:

1. The algorithm has changed: From simple trajectory reproduction, it has evolved into a requirement for 3D visual scanning plus adaptive path planning.
2. The hardware has changed: From a lightweight floating design, it has evolved into a heavy-duty, rigid spindle for rough cutting.
3. The way of thinking has changed: From pursuing ultimate smoothness, we’ve shifted to pursuing ultimate efficiency and the ability to minimize material waste.

If you’re looking to break into the casting and polishing market, forget about your past successes in the 3C industry. Don’t try to tackle a thorny bush with just an eyebrow razor.

Respect for craftsmanship and deep engagement on-site are the only shortcuts to successfully implementing automation.