Preheat sensitive alloys (like Hardox) to 100°C–150°C before cutting.
When programing CNC plasma, oxy-fuel, or laser cutters in SheetCam, achieving a flawless finish requires more than just correct feed rates. One of the most frustrating defects fabricators face is the "hot crack"—a structural or visual defect left at the exact point where the torch starts or stops cutting.
Never pierce directly on the cut line of your finished part.
With this information, I can provide tailored adjustments for your specific cutting profile. Share public link
—are the primary variables in preventing hot cracks during the cutting process. 1. The Mechanics of Hot Cracking in CNC Cutting sheetcam hot crack
Kiri:Moto is widely considered the best free and open-source alternative. It is browser-based, platform-independent, and supports a wide range of CNC and 3D printing applications.
Your approach to cutting order is critical. A standard rule in fabrication is:
Users searching for "sheetcam hot crack" have several safe and legal alternatives.
To make sure I’m giving you exactly what you need, I have to ask for a quick clarification. "Hot crack" in the context of (the CNC software) usually points to one of two very different things: Never pierce directly on the cut line of your finished part
If the cooling metal is subjected to high tensile stresses while passing through its "brittle temperature range," the grains separate, forming a microscopic or visible crack.
The allure of free software is understandable, but the risks far outweigh the benefits. Using a "sheetcam hot crack" exposes users to several severe dangers.
Hot cracking during thermal cutting is fundamentally a problem of thermal management. While the defect manifests physically on the metal, the blueprint for that failure is often laid out in the CAM software. By leveraging SheetCam's robust toolpath rules, optimizing lead-in/lead-out geometries, maintaining strict control over feed rates, and utilizing smart nesting strategies, you can minimize thermal gradients and produce clean, crack-free edges on even the most sensitive alloys.
SheetCam is a powerful tool for controlling toolpaths, but improper programming can inadvertently stress the material. Here are the primary culprits behind a SheetCam-induced hot crack: 1. Excessive Pierce Delay optimizing lead-in/lead-out geometries
If your pierce delay is set too long, the torch dwells over a single spot for too long after penetrating the material. This injects massive amounts of heat into a localized zone, creating an enlarged Heat-Affected Zone (HAZ). As this oversized puddle cools, the severe thermal contraction triggers cracking. 2. Incorrect Lead-In and Lead-Out Geometry
If the torch dwells too long in one spot, it dumps excessive heat into the surrounding material, expanding the Heat Affected Zone (HAZ) and worsening contraction stress upon cooling. Where SheetCam Fits In
Use a "Leadin Type" of Arc in your operation settings. This provides a smoother transition for the plasma arc, reducing the sudden thermal shock to the boundary layer of the part. 2. Path Rules and "Overburn"
Highly prone to forming brittle martensite phases upon rapid cooling.