A demonstration at the recent International Machine Tool Show caught our attention: Simonds International had a simulated sawing display, enclosed to look like a bandsaw but with computer screens instead of a blade, that hinted at a virtual reality. We thought we were getting a peek at sawing’s version of the virtual machining displays seen these days on machining centers and multifunction turning machines, which simulate a program and identify problems and potential crashes, allowing an operator to optimize a machining program without producing scrap.
Almost, but not quite. It was a sales tool; not exactly a predictive tool for programming or tool selection. It showed a half-dozen pre-programmed video routines that help a prospective buyer see what his options are.
But where did those routines come from? That’s where it gets interesting. The performance that Simonds was communicating, the collection of technologies that produce the routines, is based on the company’s four-part performance strategy. And that strategy can be run in a simulating, or virtual mode, drawing upon a database of thousands of combinations of machines, machine blade lengths, blade types and material types, to run predictive computer routines that determine an optimum set of operating and tool conditions. It truly is a virtual, predictive tool. Simonds has created the software. It just doesn’t lend itself as well to eye-stopping trade-show demonstrations.
A simple interface belies the thousands of options that are available with Simonds’ simulator software
Individual Performance Cutting
Simonds calls the four tool parameters, or features, that this software brings together “Individual Performance Cutting,” or IPC. The “Individual” part is explained below.
First is specialized honing of the teeth, often for rough applications, such as interrupted cuts, cutting pipes, or bundles of bars or rods. Second is customized setting of the teeth. An application where it’s very useful is in cutting beams; proper set can prevent pinching, which is a common problem in beam cutting.
Third is the company’s “Sinewave” blade back. In the U.S., this has been the cornerstone of Simond’s IPC success. It’s a ramp shape on the back edge of the blade, opposite the cutting side, that pushes the blade down into the work as the ramp passes by the roller guides and changes the blade angle relative to the work. The result is an acceleration of the feedrate, periodically, to produce
longer blade life, to speed cutting, and to improve finishes. But more importantly, the ramps make the blade pulse, or “rock,” in a broaching-type motion.
The blade-back ramps typically are spaced as far apart as the roller or carbide blade-guide spacing, or somewhat farther. As a high end passes by a roller and the ramp drops down to a low end, it causes the back edge of the blade to pivot, changing the horizontal
angle of the cutting side, because the blade is effectively wider on one guide than on the other. As the blade “rocks” on the work, the effective length of the cut is shortened. It’s like cutting a thick branch with a wood saw and rocking the saw forward and back to achieve a shorter cutting path with each stroke.
This is much easier to see in a video than to visualize it with words. Click on the youtube video link below.
https://www.youtube.com/watch?v=ckzB5umvuuE
The fourth element is tooth coatings. The demand for coatings is high in Europe, says the company, and is catching on in the U.S. This is still somewhat experimental. Simonds is testing several different coatings, which improve tooth life and allow higher speeds, much like the coatings on cutting inserts do in turning and milling.
The ‘Individual’ part of IPC
With these four variables, multiplied by different machine models, multiplied again by different materials and shapes, the individual sets of conditions number in the thousands. But if you want one individual answer, today, the IPC will likely be a better answer than a speed and feed chart.
Hello, computers.
This is where Simonds’ programming has created a predictive knowledge base that comes close to virtual operation. In addition to their experience-based data, they can incorporate your actual experience into the computations to more closely approximate the actual cut time, blade life, and so on. If you have a Brand X machine in one location, and a Brand Y machine in another, they can use the performance experience with those machines as factors.
“We looked at this program as a tool to help our technical sales people set machines up and operate them at optimum efficiency,” said Dale Petts, Simonds’ Global Products Manager. “But one of the more startling things that’s happened to me occurred when
we were working with a steel company. When we visited them, after they had been using our products for a while, we found that their sales people had our program loaded onto their personal desktop computers, and were pricing jobs based on our software. It hadn’t occurred to me that somebody might actually use it to cost out their jobs.”
Fortunately, the program proved to be an accurate and reliable predictor. So it’s an effective model, as they say in economics. If you can run a set of parameters and get a prediction that is close to the actual result, you’re effectively running a virtual version of
the machine and the tool.
And with that, you can do more than just predict one set of results at a time. As with some virtual machining programs, you can run “what-if” options and see immediate results – “How many different blade types do I really need?” “What’s the optimum number of tubes to bundle?” All, without cutting a part.
Database analysis and prediction, and virtual cutting, bending, welding, and so on, are showing up in a growing variety of manufacturing operations. We didn’t expect to see it in sawing yet, but the package of IPC technology that Simonds offers produces too many options for a simple chart. It’s a sensible and useful thing to do.
