by Staff Writer
Shop Metalworking Technology has some questions for Zoller’s Chander Bhardwaj about offline tool presetting
Chander Bhardwaj is the general manager of Zoller Canada Inc.’s Mississauga facility. He’s been with the company for more than 17 years, and during that time, has traveled throughout Canada and spoken with thousands of machine shops. Here’s what he has to say about offline tool presetting
and other productivity-boosting technology.
Shop: I’m sure you’ve heard from the owners and managers of Canadian machine shops that offline tool presetters
are expensive. What do you tell them?
Bhardwaj: I tell them that presetters are not expensive. Far from it. Assuming a shop has five CNC machine tools, a billing rate of $75 per hour, and a conservative time savings of four hours a week on each machine, that comes out to $75,000 annually. For an investment of around $20,000, that’s a very quick ROI. Add to this the reduced risk of fat-fingering an offset and crashing a machine that might cost twenty or thirty thousand dollars to repair and you’ll quickly conclude that an offline presetter is one of the best investments you can make.
Shop: Setting aside any investment costs, presetters are just one more thing for an increasingly unskilled workforce to master. Thoughts?
Bhardwaj: It’s the companies with less skilled workers who need tool presetters the most. In these situations, an engineer or programmer determines the assembly parameters for each toolholder and cutting tool. The tool crib then sets those tools exactly as outlined on the job’s setup sheet and sends the offsets to the machine control. The only thing the operator has to do is stick each toolholder in the right pocket, and if the shop has RFID capability (which I highly recommend), even that step becomes foolproof. The costs of scrapping a workpiece or damaging the machine are simply too high to do anything else.
Shop: But I already have a Renishaw tool probe on my CNC machine. Why should I bother with offline presetting?
Bhardwaj: In-machine probing systems are great for inspecting parts, establishing work coordinates, and checking for tool wear and broken tools during the machining process. They’re also invaluable for anyone engaged in lights-out manufacturing. However, using these systems to establsih tool lengths and diameters during setup or when replacing worn tools mid-process only adds to machine downtime. I’ll also argue that offline tool presetting—Zoller’s, at least—is much more accurate than an in-machine probing system.
Shop: What about tool management software, or TMS—why is that needed? Isn’t CAM software good enough for keeping track of tools?
Bhardwaj: I think every shop should use a tool management solution. There are several reasons for this, but the main one is that many shops do not use a single CAD/CAM system, nor do they have a single programmer. This not only creates inconsistencies in tool data but leads to duplication of efforts in defining the different parameters and databases needed for various jobs. With a tool management system, there’s a single source of the truth. Fully defined cutting tools and toolholders with relevant application information can be downloaded one time from the manufacturer or other source, saving time and eliminating mistakes. This database can be accessed by all departments simultaneously, eliminating confusion and duplicate efforts.
Shop: I’ve heard that some shops use a tool presetter to inspect cutting tools. Is that really necessary, and if so, why?
Bhardwaj: It is necessary, and here’s why: From our own research and what we hear from our customers, there’s a fair amount of dimensional and geometric variance in even high-quality cutting tools. Unless you’re aware of this variance, it’s easy to scrap out a close tolerance part that might be quite expensive. And even with more forgiving workpieces, unexpected variance in the cutting tool leads to variance in the machining process, downtime for part measurement and adjustment, and so on. Cutting tool inspection is really no different than checking the raw material or any other purchased product that comes in the receiving door. It just makes good sense and saves lot of money and effort.
Shop: We’ve had problems with hoarding and missing cutting tools. Does Zoller have anything to solve this problem?
Bhardwaj: You’re not alone. Many machine shops go to start a job only to discover they’re out of a certain insert or end mill. It happens all the time. They must then expedite the tools and let the machine sit idle while waiting or set up something else until the tool arrives. It’s expensive, and worse, it could jeopardize their relationship with a customer. This is why smart storage cabinets are a must, especially when used in conjunction with a tool management system. Such a strategy completely eliminates the scenario just described, while also giving management complete visibility into tool location and availability. It also lets them know which tools are used most often and where, usage and performance trends, and a wealth of other information that would otherwise remain hidden. Simply put, a robust tool management strategy can save shops a huge amount of money.
Shop: Our shop has older CNC equipment. Is it still possible to do tool life management and integrate with a tool presetter?
Bhardwaj: Simple tasks like sending tool offsets from the presetter to a CNC machine tool is never a problem, no matter how old the equipment. On the other hand, tool life monitoring and management is possible in two ways. For machine tools with RFID capability, tracking usage is quite straightforward. You simply tell the presetter to write the tool life status to the chip or an external database, and then read it into the machine as the tool is loaded into the magazine or turret. When the job is done, this value is written back and updated automatically, or if the tool has reached its end of life, the machine either stops and waits or calls up a replacement tool. If the control is incapable of these functions (which is increasingly rare), Zoller has begun offering a cloud-based system called zidCode 4.0. This relies on a presetter-generated label with a QR code rather than an RFID tag and exchanges offset and tool life information via a web service. It’s a great solution for any shop that wants to prevent offset-related crashes, save time during setups, and take the first steps towards digital manufacturing.
Shop: Did we miss any important points?
Bhardwaj: I’ve been doing this a long time, and I’ve seen recently that the industry is moving towards a totally new way of working. People are increasingly aware of the benefits that come with offline tool presetting and some of the other technologies discussed here. Even for shops that only have one or two machines, the goal should be to maximize the amount of time spent cutting parts, not wasting time by setting tools on the machine. Also, the combination of tool management, storage solutions, and offline presetter helps to reduce inventory and time lost searching for tools, further increasing productivity. Perhaps best of all is that everything is connected digitally. Everyone’s working from the same playbook and has visibility to all the shop’s tooling assets. It’s just a huge, huge advantage. SMT