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Nesting know-how

To stay competitive, fabricators should take advantage of all their nesting software has to offer

by Robert Farrell, president, Farrell MarCom Services

 

 

 

From lasers to plasma, punch, waterjet and beyond, metal processing equipment represents a significant investment for any size job shop, fab shop, steel service center or manufacturer. Maximizing and accelerating the return on investment is, therefore, critical, and it only makes sense to drive such advanced equipment with sophisticated software designed to fully leverage the machine’s capabilities. 

 

To this end, more fabricators are replacing basic software with more advanced applications provided by the specialists. To learn more, SigmaTek Systems LLC’s vice president of engineering, Glenn Durham, explains what the industry can expect to see from CAM software providers moving forward.

 

Farrell: Scrap reduction and accelerated cutting cycles are a few of the obvious benefits of nesting programs. Where else do nesting programs make a difference?

 

Durham: Nesting isn’t only about scrap reduction. It’s also about part placement for manufacturability. A main goal for fabricators beyond simply cutting and processing materials is to efficiently manage inventory. While companies like SigmaTek want to help manufacturers reduce scrap, we also provide tools that make it easier and more efficient to track and reuse drops.

 

To elaborate, there are many situations in which the location of a part on the material must be optimized before we can even consider material utilization. For example, vacuum table routers have the strongest suction in the center of a sheet. Therefore, nesting must prioritize placement of the largest parts, which need less suction to remain stable during cutting, around the outside of the sheet and farthest from the center of the table. Smaller parts must be nested toward the center of the sheet where the table suction is greater.

 

Another example is nesting for machines that drag the sheet. In these nests, the largest parts must be laid down closest to the clamps and then the parts are cut farther away from the clamps. Design for manufacturability must include understanding machine specifics to make the best nest and apply a proper toolpath.

 

Cutting machines generally come with a pre-installed nesting program. At what point should a fabricator consider upgrading to more advanced software?

 

The basic software package delivered with a new cutting machine can help most smaller shops get up and running quickly. At SigmaTek, we partner with machine manufacturers to provide a basic version of SigmaNest, called Companion. Companion is quick and easy to use, allowing parts to be imported and then cut. However, when professional fabricators want to move beyond cutting a few parts and into managing business in the most profitable and efficient way, then it’s time to move to an advanced package.

 

 

What should one look for in a more sophisticated nesting program?

 

The answer really depends on the needs of the fabricator. We find that as newer and smaller shops grow, they first need to add the capability to import parts from a wide variety of CAD systems, nest those parts in a very efficient way and then machine them with an optimized toolpathing algorithm. Advanced importing, nesting and NC are usually the basic requirements.

 

Beyond that, most shops quickly want to manage inventory and work orders, controlling remnants and reducing waste and then managing the quote to delivery process in a robust and comprehensive solution. We find that at each step in this process, the ROI is such that advanced CAD/CAM solutions like SigmaNest pay for themselves very quickly.

 

SigmaNest users benefit from interactive part and nest mode tooling, auto dynamic nesting and tooling, common-line tooling and drop door support, among a myriad of other features.

 

 

Can you cite examples of the ROI that SigmaNest is delivering?

 

For some industries and companies, the material cost drives the ROI. We recently completed a project where our nesting improvements saved an entire sheet over a production run. That was due to about a 3 percent better nesting efficiency compared to what the company was previously able to get.

 

Three percent may not sound like a lot, but since they had runs of more than 25 sheets, they got to the end of the job using one less sheet. This is a great example of material savings. But think of the savings in handling time, machine on-time, worker hours, and machine wear and tear.

 

ROI can also be seen in situations where material utilization wasn’t the main goal. As an example, a fabricator working with plywood had more orders than they could cut and no room to add another machine. Therefore, they needed to reduce the time to cut a nest.

 

Through a combination of nesting and motion optimization, the SigmaNest software helped them reduce machine on-time by more than 10 percent. Because they were running seven machines, 24 hours per day, they suddenly fulfilled production demand without purchasing additional machines or adding head count or hours to the workweek. 

 

A 10 percent run-time improvement is significant. Can those running metal fabrication equipment expect similar results?

 

I wouldn’t suggest that 10 percent run-time improvement can always be expected. That was a very specific case where ROI was based solely on machine on-time rather than material utilization. Certainly, we want to cut more material faster, but the advantage that SigmaNest brings to the professional fabricator is a comprehensive solution that allows the business to maximize the ROI based on a variety of factors.

 

For example, we worked with a company that cuts 3-in.-thick through 6-in.-thick stainless with their waterjet. Processing a sheet typically takes four to 10 hours. So, they wanted to set up a run at the end of each day and let the machine process it overnight. To minimize the chance of tip-up for these types of lights-out tasks, the company uses SigmaNest’s Part Avoidance feature.

 

By setting Part Avoidance to a very conservative value, an extra safety factor is injected into the operation. This gives the company the confidence to run the machine all night without direct supervision. Although the safety factor adds a few minutes to a multi-hour run, it allows a plate to be cut every night, ramping up ROI beyond nesting efficiency.

 

 

 

What are the biggest nesting challenges fabricators face today?

 

Fabricators are challenged by both the high cost of machines and the difficulty of finding skilled employees qualified to program and run increasingly complex machines and shop processes. But we can help address those challenges through a two-fold process.

 

We are making software that helps keep machines running continuously and, at the same time, we are placing better tools in the hands of programmers. We are increasing and improving automation control through sheet loading, part picking and scrap processing while also making it easier to run these advanced features from a software “command central.”

 

One approach for dealing with these complex challenges is by importing assemblies and creating multi-machine process plans. Fabricators are increasingly concerned with more than simply drawing and cutting parts. They need a solution that also deals with the assembly of parts that may be cut on a variety of machines.

 

Therefore, the newest version of SigmaNest recognizes which parts need to go to the tube laser, the press brake and the plasma cutter and can then unfold sheet metal parts and task and nest for each different type of machine – all while managing the flow of different kinds of parts through the shop floor.

 

 

 

Where do you see the industry as a whole five years down the road?

 

Industry 4.0 and the Internet of Things get a lot of press. However, I think it’s unlikely that these will be brought into the fabrication industry as a complete package. Instead, components of these new technologies will be incorporated into our workflows to improve processes, efficiencies and quality.

 

So, I think we will see more companies taking advantage of process monitoring and machine utilization studies. Automation, just-in-time nesting and toolpathing will be seen as powerful ways to get more return from investments already made.

 

On an almost daily basis, manufacturing processes are being revolutionized by more complete and more accurate knowledge of what is really happening on the shop floor. Therefore, when fabricators invest significant time and money into their machines, it’s critical that they use the very best nesting solution available to manage and extract the best quality parts. 

 

SigmaTek Systems LLC

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