This is the first time Under the Hood has looked at a system rather than a product. This system consists of the following components, the main players in our story:
- The MD store, a storage tower that feeds the S4 punch and shear;
- The S4 punch/shear machine (in our case, the S4Xe.30) with multiple press head configuration;
- The MCU (universal cartesian manipulator) automated sorting/buffering/conveying system;
- The P4 automated feeding/conveyor PCD;
- The P4 machine (in our case, the P4L-2520); and
- The P4 unloading conveyor SAP.
We’ll look at these pieces individually and as a system, and at the end, you’ll see the results of putting this system (rather than individual machines) to work on a project.
Machine tool automation is a really interesting topic. It gains interest and depth when you consider it in a system comprised of multiple machine tools and automation systems. The system we’re about to explore fits into fairly high-volume environments, but at any moment can change into a made-to-order, on-demand system.
Like the automakers’ goal of getting one horsepower per cubic inch (achieved in 1957), many machine tool makers of today would agree that a touch-free automated machine is a good goal. It’s an accomplishment to achieve in a machine, and it’s a further accomplishment to achieve it in a system with multiple machines. The S4 + P4 line did achieve it, and we’re going to explore how.
First, it would not be a fair test to give the system a job it could not do, and in this case the end project was a shelving unit with precise specifications. The job was done by utilizing a punch, shear, and panel bender, and all the automation that was integrated into each machine plus separate (but integrated into the system) automation help along the way.
The game plan goes something like this: Program the equipment. Stock the MD with the sheet metal you’ll need for the project.
Before we hit the “go” button, a human factor is in play, and that is it can be difficult getting used to different interfaces on different machines. With Salvagnini’s FACE system, the controls are organized the same way for each machine, it’s just that the actions and specs are different, but the human-machine interface (HMI) is nearly identical across the board. It’s a bit like Southwest Airlines only flying 737s—all pilots can fly any airliner in the Southwest fleet. That same idea makes it much easier to transition to managing another Salvagnini machine.
Derrick Clark, Senior Application Engineer at Salvagnini gives us a quick intro to the software:
Let’s go—push the button
It looks like we’re ready, materials are in place, programs are in place, let’s start. We can see our nest, and we select a program. After just a few checks, Clark hits start and the system comes alive—starting with the MD, which chooses a set of sheets, checks their location, activates the suction cups, pushes some air into the stack, and the sheet is brought down the elevator. Once it reaches the base level, it is conveyed to the S4.
And the video stops just before we get to the S4. A few words about the S4 before we get to our next video. First, it behaves well with other machines in the line. There are loading and unloading options that maintain process flexibility. Second, it’s quiet. Third, it uses a multipress head with up to 96 independently actuated punches, and they’re stored where they work. In fact, you can use two or more punches simultaneously, dependent of course on the proximity of the desired holes. Tool changing time is effectively zero; they’re always ready to go.
The maximum sheet size of our S4 is 120 in. x 65 in. Maximum thickness ranges from 0.20 in. for aluminum to 0.08 in. for stainless and 0.137 in. for mild steel. The minimum thickness is 0.02 in. or 25 gauge. For shearing parts from nested sheets, the S4 cuts either independently or simultaneously on x and y axes using the integrated right-angle shear.
In short, there’s a lot going on inside the S4. It being too difficult to catch it all by standing outside the machine, we have accepted the kind offer of Salvagnini to use its video animation of what happens inside the S4 and inferentially how it happens, too. The animation moves right along, but it is in slow motion. Nevertheless, one really has to pay attention. In an effort to avoid audio copyright concerns, this is our first silent movie:
If you need to watch it again, go ahead, we’ll wait.
After the S4 finishes, the blank is moved across the conveyor and (in our case, at least) across two conveyor systems to the P4. Why two? Well, besides buffering, in which you can offload parts if there is a bottleneck downstream, you can also introduce other pieces to be done by the P4 at this stage (we’ll see an example of that later). Meanwhile, take special note that the nest we saw briefly before we hit “go” had the parts in the best orientation for the nest. That orientation might not work so well when it’s time to bend, and so we see that the MCU, the universal cartesian manipulator, reorients the piece for optimal use in the P4. Once we’re there, we get to see the start of the panel bender’s many tasks:
Naturally we were a little curious about the conveying system and its speed on a part that needs no reorientation. Here is the result:
In less than 15 seconds, what was once the property of the S4 is in the hands of the P4.
The bend/shear combination
The P4 performs like a panel bender and a shear. That’s two shear functions in our line (the S4 does it too). The reason is that some shearing actions cannot be done early in the process.
A wide range of bending happens in the P4. In the upcoming videos you will see a “C” shape in the panel bender; the points of the “C” are for downward (using the higher point) and upward (using the lower point) bends. The opening of the “C” can move down or up depending on the bend needed. And as you’ll see in the next few videos, the bends can become quite fine and precise. In particular, look at what the bender does to the edges on all the pieces in our project.
You will also see the part being manipulated before and after its time in the bending phase. The manipulator backs the part off, or feeds it in, as needed, and spins it to align it for the next operation in the bender.
After the part has been through the bend program, it is sent to the unloading area by a shuttle. It arrives at a series of rollers, which are pre-programmed and reverse their direction when the part gets to the right x-position. At that point it stops, and the far ends of a series of roller bars ascends, and the part slowly goes down to the pickup area.
Let’s get a look at the process now:
This system features a lot of automation. Even the delivery system is automated, as we see in this short video, a different part gets a different landing area:
And, so that you get a better idea of what’s happening in three dimensions at the delivery stage, here is a video of the unloading area but taken from a spot 90 degrees different from the other videos:
And to get back to our “C”shape in bending and shearing, the following video is from an embedded camera. It gives us a good look at the bending and shearing operations of the P4. The shearing action cuts a spacer support that will be used in the final assembly in our project. Here’s a look:
Some parts (such as the spacer/supports) are not big enough for the unloading bay to handle, and must be treated differently. Luckily, there is yet another pathway for these parts. Instead of going to the front of the unloading bay, these parts travel a different path to the side of the unloading bay. This next video contrasts the two delivery methods:
Hot job coming through
No matter how large a part, no matter what the edges look like, we can see that during the run of the job, the human participation is to check the setup, hit go, and collect the parts at the other side. However—especially for job shops—the hot job or emergency part creation comes up on a regular basis.
It seems challenging to stop all the automated work and start a new job. Really, it’s not too challenging. Pause the current job, load the program(s) for the hot job, and you can manually inject it into the process (in the example you’re about to see, we put the blank into the P4 feeding conveyor manually). Take a look:
Finally…the parts become a project
We have reached the final step in the process, and that is collecting all of the parts and assembling the final product. The following video shows the power of product design. There are no screws or bolts in this product; because of the strengths and accuracy of using the panel bender, everything slides or pops together without an assembly line or department.
Derrick Clark takes us through the last lap in this video:
A lot of things are at work simultaneously in the S4 + P4 line. If its many parts were instruments in a orchestra, your job as the conductor is to simply start the orchestra playing—and once in a while, if needed, temporarily change the song.