For machine shops in a competitive global marketplace, keeping spindles running and making product is the only way to stay in business. Still, adding a new piece of equipment, even with the promise of improving the efficiency of your existing ones, may be a difficult sell to management.
According to the tool presetter manufacturers interviewed for this article, it is getting easier to make that case.
What are tool presetters? “These devices measure tool offsets after the tool is fitted into its holder, measurements that are otherwise made in the CNC machine itself,” explained Andrew Esposito, OEM sales manager for Koma Precision Inc., East Windsor, Conn. The traditional method is to manually touch-off tools after installing the tool and assembly where it is going to cut. This is convenient if the operator is a seasoned and expert professional.
“Another method is to use an onboard tool probe,” explained Esposito. This might not require as high a level of expertise, he noted, but, like manually touching off tools, it still requires time where the machine is not cutting chips and making money.
“The offline tool presetter takes those measurements before installing the tools [and assembly]. It allows you to kit up your jobs and change over your machine in a much more effective and quick manner,” he said.
Once the measurements are made, the tool offsets needed for accurate machining are entered into the CNC. This automates the process of capturing the required tool offsets. “It minimizes the need for a skilled, experienced operator and captures more data than is possible through on-machine measurements,” he said.
The downside is that presetters are yet another piece of equipment—and, yes, they take up additional floor space. However, with basic introductory machines available from Koma Precision and other providers in the $10,000 to $20,000 range, a positive return on investment is easy to make. Like other providers, Koma Precision offers a graduated set of machines, from basic to highly capable. The more capable tool presetters measure larger tool assemblies, provide greater magnification, and easier data input and output.
It would be easy to speculate that only larger companies might be able to make the case for investment in these devices, but Esposito dispels that notion. “There is interest in these devices from small and large companies and everyone in between,” he said. “We have sold tool presetters to shops with only two cutting spindles. Our tool presetters helped that company keep their machines cutting up to 80 percent of the time with a tool changeover that took only 15 minutes instead of 45,” he said. “You can also check more features, like tool runout, that you can’t measure once it is installed on the machine.”
The company is releasing a new Prime line of tool presetters aimed at the entry-level market. “It gives you all of the advanced features that shops want, like automatic tool measuring, non-contact measuring, basic tool management, creating the tool offset file, and tool inspection at what we think is an affordable price,” he said.
Setting aside the need for a skilled operator, Steven Baier, vice president of sales for Haimer USA LLC, Villa Park, Illinois, offers hard numbers. “When you look at the cost of a machine shop, 50 percent of total cost is machining time,” he said, “and 30 percent of a shop’s total cost is general and administration cost, such as labor, lights, and other expenses.” Four percent is cutting tools and one percent is toolholders, he said.
“The easiest way for any machine shop to save money is to [increase machine uptime],” he said. He reiterated the point—tool presetters keep spindles operating.
He believes that tool presetters, in general, are especially useful in measuring more complicated tools, such as step tools or indexables. “For example, imagine a two-step drill with a ½” (12.5-mm) start point with a 1″ (25-mm) diameter towards the bottom. The distance from the first step to the second could be critical and it is impossible to measure that with an indicator in the machine,” he said. “With a tool presetter that is very easy.”
Another example is how easy it is for tool presetters to measure indexable tools used in specialty applications. “These include diamond-tip tools if you’re in the automotive industry. Other industries like aerospace utilize high-end multi-flute cutters for [machining] exotic alloys like titanium or Inconel,” said Baier.
For tools with multiple inserts, operators have to ensure the inserts are seated correctly. This requires running an indicator across all of the inserts. “If that is, say, 15 inserts, it’s going to take much longer to put an indicator in the machine and make that measurement. You’re wasting a lot of time,” he said. Not only are these complicated tools much easier to measure in a presetter, they may at times be impossible to measure without one, he added.
An objection Baier often hears from shops without tool presetters is they have laser or auto tool setters already in their CNC machines. Why buy a tool presetter in addition? These machine tool probes are lasers or touch probes.
“These probes can check height, diameter, and runout, but it takes a lot longer than shops might realize,” he said. He cited numbers from an experiment Haimer performed, claiming that to set a tool manually took about 300 seconds, while a laser-based, in-machine probe took about 150 seconds, and a high-end Haimer tool presetter took about 32 seconds.
“With a post processor it takes about 16 or 17 seconds per tool set,” Baier said. “In-machine tool probes or lasers are very useful for basic inspection or broken tool detection, but I will claim a tool presetter is much faster for finding height, diameter, and runout.” Further, a shop must buy one laser for each machine. With one presetter you can set tools for all the machines in your shop, he noted. “This alone is a significant savings in both time and money,” he said.
There are other advantages of presetters, according to Doug Sumner, TMS product manager, BIG Kaiser Precision Tooling Inc., Hoffman Estates, Illinois, a supplier of Speroni tool presetters. “[Tool presetters] measure the cut path and can also look at each cutting edge to make sure that the runout is within limits.”
Think of tool runout as the potential “wobble” of the cutting edge while spinning. Even one micron can make a difference in degrading tool life and surface finish. “For example, we had a customer who was machining aluminum where the surface finishes were critical. They were running 6-12″ [152.4-304.8 mm] face mills with adjusted pockets and wipers and [using a tool presetter] they were able to set that within 1 µm, which gave them phenomenal surface finish.”
Like others offering tool presetters, BIG Kaiser offers a range of machines, from basic, entry-level devices to high-end advanced models with repeatable precision better than 2.5 µm. “The most basic model, the STP Essentia, is a good, solid machine for measuring tool offsets, runout, some geometry like angles and nose radii. It produces a tool offset table, but you can’t add any options or upgrade the controls,” he said. “It works for probably 50 percent of shops.”
The medium and higher-end models satisfy different needs, often after a manufacturer has owned a basic model and comes to realize the benefits more features can provide. Some of the higher-end models from Speroni include ones that can shrink-fit the tool into its holder right on the machine, then take measurements and provide the data as desired.
The accompanying control software from Speroni, like other providers, follows the same philosophy of increasing capability in three levels, according to Sumner. These include Simple Vision, Edge, and Edge Pro. The more advanced software also interfaces with external tool management systems and provides connectivity through bar codes, QR codes, and RFID read-only or read/write capabilities, according to the company.
The Edge Pro illustrates one of the key capabilities of many modern tool presetters—generating 3D CAD models from the measurements. “These 3D models of the tools can then be used in a CAM program,” he said. “These are not the CAD nominals, but the actual measurements of the tool and its holder in a CAD representation. We measure from the bottom of the holder up to the tip of the cutter, following the edge, and create a solid model that is then exported to any number of popular CAM programs.”
Sumner thinks that the broad concepts behind Industry 4.0 and smart factories, such as data sharing and communication, are important elements when choosing presetters. “A presetter with tool management software blends nicely into communication and data sharing,” he said, especially if you can get important details like the actual geometry of the real tool in its holder. In the same vein, at IMTS 2018, BIG Kaiser, working with FANUC, demonstrated an automated cell that featured a tool presetter shinkfitting tool assemblies handled by a robot. (Editor’s Note: See a case study on a Speroni presetter on page 42 of this issue.)
Matt Brothers, Industry 4.0 Tech Center manager for Zoller Inc., Ann Arbor, Mich., certainly agreed with the impact that “smart factory” concepts are having on the tool presetter market. Zoller produces a graduated line of introductory to advanced tool presetters, along with shrink fit devices and tool balancing machines. It also produces tool data management systems.
“We are seeing that many tool presetters are going into central tool rooms,” he said. “This is enabled by data sharing and connectivity. Various locations throughout a factory, say the production floor, regrind facilities and tool storage locations, are all connected through tool data management systems,” he explained. Since they are all working from the same database, the state of the tool and its measurements are all traceable. In those cases, the tool assemblies are prepared, measured, and inspected in that central location, then transferred by cart or hand-walked over to the proper machining cell.
Zoller’s higher-end machines, such as the Venturion 450, also convert measurements of tools and assemblies into 3D models that can be used in a CAM machining program. “There are so many measurements available on a tool presetter you just could not do on a CNC machine that can only touch off,” said Brothers. “Not only can we verify the actual cutting tool edge geometry, we can also confirm that it will cut the part accurately. I can now maybe start to add some inspection packages on the machine, measuring the runout, or wobble. But not only that, I can also verify where the issue is.”
Operators can determine if improper runout is due to the tool, the holder, or even the spindle. “What we can do is eliminate the runout from the holder when we measure the tool,” he said. “One of the optional packages we can add to our Pilot 3 software is ‘wobble compensation.’”
Brothers often needs to explain to customers, even those that have installations of Zoller presetters, some of these extra capabilities and how useful they are for troubleshooting—including checking the tool when first received, final inspection, tool assembly verification, and even using the camera to measure tool wear.
BIG Kaiser’s Sumner relates the same idea, that a smart customer can find troubles in the workholder and in spindles by eliminating any potential error from the tool itself.
Another key feature of a programmable tool presetter is its ability to take potential human variation out of the mix. “For any given tool and assembly, you write a measurement program once, you save it in the machine, and when that tool assembly needs to be measured again it’s the exact same measurement sequence,” said Brothers from Zoller.
This is in contrast to the operator doing a tool touch-off, a process that could vary widely even between skilled and experienced operators. This leads to a key point Brothers made—implementing a new tool presetter means a culture change and a change in the process. “You need to engineer it into your process to maintain consistency in the measurements,” he said.
Tool presetters, like other machine shop equipment, both live in and take advantage of emerging smart factory or Industry 4.0 concepts. The data from a tool presetter needs to find its way into the tool offset table of the machine’s controller. It is a question of measuring equipment working together, rather than in competition. Tool presetters and in-machine tool setters provide different information at different stages of the process. Combined with other sensor data, they provide the basis for a true smart process around machining centers.
A good example comes from Heidenhain, Schaumburg, Illinois. It is the manufacturer of a commonly used CNC, as well as many of the encoders and electronics used in tool presetters. “We think working with tool presetting companies is very positive,” said Gisbert Ledvon, TNC business development manager for Heidenhain.
He discussed an example of an integrated approach demonstrated at EMO 2017 as well as at the Heidenhain applied technology center in Schaumburg. “We showed the entire physical process of taking data from a tool presetter, transferring it into the machine tool’s offset tables, and verified and simulated the process with the new tool data.”
During the cut, the process was monitored using the controller’s state-of-the-art monitoring system. “We also do an in-process inspection using Heidenhain touch probes, making sure the data is correct,” he explained.
This makes predictive control possible, for example notifying the operator that a tool might only have 15 minutes of life left for a 30-minute cut. Ledvon added that data transfer is vital to creating a useful environment. That is a sentiment shared by all the tool presetter providers interviewed for this article.
“When you are looking at tool presetting, make sure you can interface directly into your CAM system and into your machine controllers,” said Ledvon. “Easy data transfer is key to success.”