by Noelle Stapinsky
The union of punch and fiber laser cutting processes in one machine is like a Swiss Army knife for job shops.
Punch and C02 laser combination machines have been on the market for decades, bringing the dual capabilities to shops in a single footprint machine. And now, with the fiber laser market growing at lightning speed, combination machines are seeing renewed interest in the marketplace.
TRUMPF introduced its first punch/C02 laser combination machine in 1979. “So for us, these machines are not new. But over the past five years the combination machines have definitely taken off since the introduction of our TruDisc laser. Marrying the two technologies has given us even greater flexibility,” says Roger Michaud, TRUMPF TruPunch and TruMatic North American product manager. “It really is the next generation and a whole new market segment created by the fiber laser revolution.”
Of course, the argument has always been around justifying the cost of a combination machine. Sure, shops can invest in two independent machines, but when conducting laser cutting, the punch press may be sitting idle and vice-versa. And for many shops, floor space comes at a premium. “Some shops actually consider the square footage of their shop and how much money it’s making,” says Tim Brady, Amada’s combination machine product manager. “For every machine that takes up an amount of space in their shop, they expect a return from that real estate.”
Michaud agrees. “The ability of having a machine capable of multiple features in one area is truly beneficial. Your typical mom and pop shop might only have a budget for one machine and they need it to do multiple things. Punching is much more efficient and less costly than laser processing. But with a combination machine you’re not only saving money with the speed of the unit, you’re saving a tremendous amount of money on tooling. The laser is capable of unlimited part geometries, so you don’t need to purchase special tooling to do a certain knock out or cut out that you would need for a traditional punch. We say, ‘you’re getting a laser part at a punch price’.”
One of the biggest benefits of employing a combination machine is the reduction or elimination of secondary processes such as tapping, deburring and extrusion, significantly reducing material handling tasks.
“The marketability of combination machines is all about the flexibility it gives shops. You can do your punching and forming and then the laser cutting for the end quality all in one footprint,” says Dan Caprio, punching product sales manager for LVD Strippit. “Processing parts on one machine will deliver a better quality because you’re not moving parts around as much and you don’t have to buy special tools for secondary operations. And it creates shorter lead times.”
Brady provided an example of one customer that was processing a lot of different parts. For an order of 100 blanks of a particular product, the shop would manually pull large sheets from its inventory, shear them down to smaller blanks, move those to the punch to create holes, then cut out the profile with a laser. After all of that, the part required forming and tapping, which an operator would do manually.
“By the time they’re done with the blank and ready to take it over to forming, they’ve put in 40 hours between when they started and finished,” says Brady. “This customer bought one of our high-end combo machines and was able to take that same job and process those 100 parts in four hours.”
Amada’s fully automated combination machines offer automatic loading and off-loading, as well as a part picking and stacking option. “Parts can be tapped, formed, cut, picked and stacked, and ready to be taken over to the press brake, which is all done pretty much unattended. There’s really no operator intervention other than getting the machine set up and programming it,” says Brady.
Typically operators would have to shake the parts or pry them out of the skeleton. This is a labour intensive process and parts often fall on the floor or aren’t stacked properly. With an automated parts removal system, the parts are neatly stacked in the proper grain direction and orientation, which saves a lot of wasted time and material when the parts are moved to the press brake, for example. And it decreases the possibility of human error in the next process.
TRUMPF’s combination machines also reduce material handling and operator intervention with part separation automation. “It is a cost, but many could never equate a value of the cost of parts moving from one machine to the next,” says Michaud. “It might take three minutes to run a part on one machine and 18 minutes on the next. But you had to sort the parts for two minutes, stack them for four minutes and then move them to the next machine. If you reduce all of that it’s a huge cost benefit.”
To reduce secondary processes, TRUMPF machines can tap, add extrusions and countersinks, or do pinch forming and bending. “One of the biggest functions that we’re finding in demand is the deburring of parts. We have a wheel technology that allows a roller to go around the material to crush the burrs off. This makes it much more manageable when it comes to processing these parts. And all of these functions are automated within the system,” says Michaud.
Tooling on the fly
LVD offers a few different combination models—two 30-ton thick and thin turret machines—and its PX series, a 20-ton machine with an automated tool carousel. “On this system there could be 20 tools in the carousel, or with our EMP tool changer customers can add an additional 40 tools,” says Caprio. “The turnover or lead times are shorter because you don’t have to wait for tools to come in.”
He continues, “and on our machines you can punch up to ¼-inch material, and laser cut up to 3/8-inch material. You can process an entire 5×10 sheet of material without needing to reposition it. That equates to better tolerances because you’re not moving the sheet from the punch to the laser.”
The sheer speed of today’s fiber lasers and the fact that they require fewer components than a C02 means greater repeatability and reliability. “And there’s a huge cost savings right there,” says Caprio. “Your tooling costs will go down because you’re going to be laser cutting most of the outside contours, a process that you’d typically use your punching tool to do.”
Brady says, “if we compare a combination machine to a straight turret, generally the downside is in the set up. An operator may spend a lot of time loading and unloading different tools for different jobs. That’s a big area where lasers replace turrets in a lot of ways. You don’t have that kind of set up on a laser.”
ACIES, Amada’s flagship combination punch/laser model, has a 300-station auto tool changing system. “With combination machines you still have to load and unload tools depending on what the job needs. But usually you can get away with not a lot of set up and the ACIES tool changer basically eliminates that set up,” says Brady.
Combination machines are also becoming an attractive option for shops using galvanized steel or processing stainless steel for certain industries that require a scratch-free process.
“All or our machines come with a brush table option,” says Michaud. “We have a descendent die and an active die. The former is going to drop your punching tool below the material surface when you’re not punching and the part is moving, then rise back up. So if you’re doing any large forming, or making an outside panel with louvers, you’re going to drop that die out of the way, the material will move, and the die will come back up to punch the next part. The same process occurs with the active die. This will give you a true scratch-free process.”
“Scratching has always been a big problem with turrets and lasers,” says Brady. “This is another big feature with our ACIES machines. It has a full brush table and a retractable die system. The lower turret is under the table and when you select a tool, the die rises up to the pass line and punches the hole or makes your form. There are a lot of companies that produce stainless steel or galvanized parts, with which scratching can be a real detriment.”
The demand for these dual process machines is growing for those playing in the automotive and agricultural industries as well. “What we’re seeing with heavier duty equipment is that instead of using ½-inch plate with a welded on louver, shops can get the same structural integrity with a ¼-inch plate by adding beading to it,” says Michaud. “Rather than being aggressive with thick plate, heavy-duty panels, we’re seeing engineers exploring ways of reducing the weight of the panel, which is making it more cost effective and user-friendly for the operator. And as prices of steel keeps increasing, this is a way to control that price.”
With so many options to increase cycle times and ease material processing procedures, while decreasing labour intensive and material handling procedures, justifying the cost of these machines is almost a no brainer. And as automation evolves and job shops continue to look for ways to eliminate unnecessary manual processes, combination systems are quickly becoming the machine of choice. SMT