Folding Technology In Bumping Formed Radius Parts
Sheet Metal Folding technology has made inroads into the precision sheet metal market over the last decade. The attraction was the folding machine’s ability to process large, unwieldy parts, the kind that would require two or three people to process on a press brake.
The design of the folding machine is perfect for these complicated sheet bending parts. An operator places the large piece of sheet metal on the sheet support table and backgauge and moves it against the back finegr stop, and the vacuum gauge system grabs the metal bending part to start the forming sequence. A coordinated process begins: The vacuum back gauge moves the sheet metal, the clamping beam holds the sheet metal in place, and the folding /forming beam makes the forms in an upward or downward movement.
CNC folding machine automatically adjusts the position of the folding beam and pivot point between bends, adjusting for proper radius, crowning, and flange length. Folding machine operator doesn’t have to touch the sheet metal part again until it needs to be rotated to continue the job or removed from the machine.
Most of fabricating shop or companys are looking for CNC press brake operators. Either they can get the better press brake operator from other competitior's company or invest money in training with qualified cnc press brake operator.
CNC folding machine operator doesn’t need the experience of how to bend metal. The operator only needs to know how to run the machine. The folder takes care of the rest.
Typically an folder operator working on a folding machine is working with a single set of highly-flexible tools, able to bend any material type and thickness that the machine is rated for. Tools are arranged to the lengths required for the job, so that workpieces of different sizes can be formed. (Special tools, such as a tall clamping beam tool to handle deep part profiles, might be used in folding machine applications. But tool changes are still limited to adjusting the width of the clamping tools to fit the part size.)
For example, if an operator has just completed a job with a 72-in.-wide workpiece and is about to put a 36-in.-wide sheet on the machine, he needs to have a toolstation that is 36 in. wide. A certain portion of the clamping tools need to be moved aside to accommodate the new part length, which might take a couple of minutes. The operator typically never has to strip all of the tools from the machine as different jobs are done.
When tools changeovers are frequent and productivity is of the utmost importance, folding machines can be equipped with cnc automatic tool changers. These mechanized grippers automatically arrange the clamping tools to accommodate the next job. These changes are done in seconds and occur while the operator is preparing for the next part run. This parallel process eliminates the downtime from tool change as other work is being performed during this time.
Experienced CNC press brake operators are required to fabricate high-quality, complex parts on a consistent basis. With sheet metal folding machine, less-experienced machine operators can make high-quality, complex parts after only a short amount of profile bending training.
Fabricating shops or company struggling to find cnc press brake operators also are having difficulty recruiting welders. There aren’t enough of those people willing to work in metal fabricating environments, forcing many businesses to jump into robotic welding. For those automated systems to work, the workpieces have to be formed with a high level of consistent accuracy so that fit-up meets welding specifications.
CNC sheet metal Folding machines typically form bend angles to plus or minus a third of a degree or better. Moving the responsibility of part quality from the operator to the machine means the first part is going to have the same quality as the last part in the job.
Now consider forming a NEMA-rated enclosure on a press brake. This type of enclosure has 16 bends, four bends on each of the four sides. That means cnc press brake operator has to gauge that workpiece 16 different times, flipping it repeatedly throughout the process. If any of those gauge points are missed, the mistake is going to compound itself with each subsequent form, resulting in a scrapped piece. Even worse, If that out-of-tolerance part is passed along to downstream operations, the cost of that bad part only multiplies. Keep in mind that the larger the part, the more difficult holding accuracy becomes.
But when we put the same part on a folding machine requires the machine operator to be engaged in the workpiece placement only four times—once per side, and never requires a flip. The opportunities for error are greatly reduced when compared to trying to do the same job on a press brake.
Not only does repeatable part accuracy delivered by the folding machine simplify the use of robotic welding or allow for implementing laser welding, it can significantly reduce the system cost by simplifying the fixtures needed to hold the parts in position during traditional arc welding.
Better Bump Bending In CNC Sheet Metal Folding Machine
Metal Profile Bumping bending to create a radius on a sheet metal part is a specialty capability that some metal fabrication shops offer. CNC Press brakes often are used to bend radius, either with a customized radius tool or by making shallow bends as the part is incrementally fed from bend to bend. This is an especially challenging task on a press brake and one requiring a great deal of skill and preparation, which is motivation enough for some shops to avoid these lucrative jobs.
A folding machine can create a radius form with little more effort than a sharp bend. The part is held by the vacuum back gauge, and the folding beam locks into a shallow angle. As the part is fed forward, the beam clamps against the sheet making shallow incremental bends. The smoothness is determined by the feed increment, and the radius size is a combination of the number of increments and the angle of the folding beam. A radius on a folder is nothing more than a program, and no more challenging to produce than any other bend.
This type of form is produced quickly on a folding machine, is extremely repeatable, and eliminates the risk from those highly profitable jobs.
For the most sheet metal bending part, cnc press brakes now are designed to keep even nonexperienced operators safe. Pressbrake operator finger Laser Guarding system ensure that fingers are kept clear of the pinch point, and ram control adjusts the bending speed to suit part size. Operators are less likely to suffer compression injuries than ever before.
Even with those improvements, press brakes still require manual part manipulation. Given that most experienced press brake operators are closer to retirement than their original start date of employment, that’s asking a lot from an individual operator—shift after shift, week after week. That’s a lot of wear and tear on shoulders and wrists.
Folding machines address those types of repetitive motion injuries by eliminating that type of part manipulation. Once loaded onto the support folding table, the part moves effortlessly on a bed of steel ball transfers. It takes little effort to roll the part against its gauge point so the vacuum gauge can take over and process the bends needed. Adding conveyors to and from the folder, an operator never needs to support the part weight.
CNC press brakes still have their place in today’s metal fabricating companies. As a general rule, if you have a part that you can hold in one hand easily and manipulate through the bending cycle on a brake with no problem, that part should stay on a CNC press brake.
CNC Press brake also can do some things that folding machines can’t. A single-hit tool can be placed in a press brake to create a 90-degree material thickness offset, which is something that a folding machine can’t make. As press brakes have large tonnages, they can create flat hems repeatedly without a problem; a folding machine can produce nice teardrop hems, but it might struggle to match what a press brake can do with these types of forms.
Also CNC press brake can bending longer and thick sheet metal profiles then any bending center or folding machine, some special forming or punching profiles are also available get them done in CNC Press brakes.
