MultiCam Canada and SigmaTEK, the makers of SigmaNEST software, recently teamed up to present a webinar entitled “Shop Floor Cutting Techniques for Bottom-Line Improvement”. We showcased a number of different plasma cutting and nesting techniques designed to increase plasma consumable life, decrease the amount of scrap material, decrease overall cutting time, and ultimately improve your shop’s performance.
We’re going to take you through these different plasma cutting techniques and highlight the uses and benefits each provide.
Chain cutting is ideal when parts are situated around a central location. The idea is that only one pierce is needed for the entire piece. Most plasma consumable wear and tear is experienced during pierces. This is when the most amount of heat is generated at the torch head. All consumables are rated on the number of pierces they can sustain through their useful life. In this example we’re able to cut the pierces needed down to 25%. Expanded over time this can lead to significant cost savings.
Common Line Cutting
Common line cutting will nest parts directly beside one another, where a part can share the same side as another part. As with chain cutting, common line cutting can greatly reduce the number of pierces needed to cut multiple parts. It also greatly speeds up cutting as the torch head can cut in one continuous motion. However, you do sacrifice some cut quality when using common line cutting. Plasma swirl causes differences in the bevel angles for the left and right edges of the cutting kerf. If the part you’re cutting requires a high degree of accuracy and cut quality, then common line cutting is not recommended.
As the name implies, bridge cutting leaves a tiny “bridge” connecting each part. This technique is ideal when you’re cutting a number of the same part on the same sheet, and these parts need some sort of secondary processing. The part we cut below was designed for a press break. Instead of cutting each piece, and then moving each piece individually to the press break, keeping a connecting piece of material allows all of the parts to be moved, and subsequently bent, together. This can result in significant time savings. Again, this technique is not designed for all parts. Breaking of the bridge will ultimately result in a small tab. A small amount of secondary work would be needed to smooth out this tab, and if perfect edge quality is needed, then the time saved with the bridge will be lost in the secondary processing.
i-Pierce is a technique designed by SigmaTEK and is a fantastic method for reducing the number of pierces needed, especially for thicker metals. This program will insert small loops into the cutting path, between the nested parts. These loops become the start of the next cut. Rather than needing to start a new pierce, the plasma cutter is able to use an edge start, thus reducing the wear on the torch consumables.
MultiCam Canada is a licensed distributor of SigmaTEK software. If you’d like to learn more about the many features and capabilities of SigmaNEST, please visit www.sigmanest.com.