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Aluminum Stacked Sheet Cutting

  • Aluminum Stacked Sheet Cutting
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CMS' patented stacked sheet aluminum machining process is a breakthrough technology - meaning that today's' stacked aluminum producer no longer needs to manage difficult and inefficient machining processes to produce a myriad of different aluminum parts, and can eliminate the traditional stacking, drilling, riveting or screwing of the stack together, partial CNC machining leaving "micro-tabs" on the part edge, removal of rivets or screws at the end of the machining cycle, followed by lots of handwork, which requires manually breaking the parts free from the sheet web, along with manual and inaccurate grinding and shaping of the final parts to remove these tabs. CMS' patented stacked aluminum machining process changes everything, and not only improves the total cost and time, eliminating all the extra work and effort, but makes it possible to unload finished, perfect parts directly from the machining center at the end of the cycle! 




FXB - stacked sheet aluminum, CMS' patented "ring pressing" device, single or double table

FXB, CMS' moving table class CNC machining center, with CMS' patented "ring pressing" device for stacked aluminum sheets, from which an endless variety of part sizes and shapes can be obtained, has completely changed the way stacked sheet aluminum cutting is done. FXB's moving table platform, with traditional vacuum system in use for the bottom sheet, is provided with CMS' patented "ring pressing" technology, by which a stack of sheets, secured only at their corners, can be processed with the "ring pressing" device. The "ring pressing" device carries out its work using traditional "micro tab" processing methodology, in which the parts remain attached to the sheet web via small tabs, so that the majority of work is finished, excepting the tab removal. During the 1st machining phase, the "ring pressing" device does its work at "low pressure" and holds the stack together, while moving over the stack surface with a low pressure, so that no gaps are allowed between sheets in the stack, and at the same time, leaving several small tabs around the part perimeter so that the part doesn't move during machining. During the 2nd machining phase, the "ring pressing" device executes a high pressure cycle on the stack at each tab location, in which the "ring" is motionless, but the axes are free within the "ring" to interpolate +/- 20 mm to machine away the tabs, yet leave a perfect edge and a part now free to be removed from the sheet stack, not attached to the web any longer. This is completely different than the traditional methodology, which requires stacking the sheets, drilling holes and either screwing or riveting the stack together, machining the parts with the "micro tabs", unloading the stack of sheets, removing the screws or rivets and then manually breaking each part free from the sheet, as well as manually grinding the "micro tab" away, resulting in lots of additional time, reduced edge quality, and reduced accuracy.

The "ring pressing" device comes equipped with CMS' high velocity chip extraction system, reducing the scratch pattern on the top sheet, and in many materials, especially the harder aluminum grades, leaving an acceptable and very small surface depth scratch pattern on the top sheet, acceptable by established standards, a surface free from unacceptable damage due to scratching of any chips during machining processes; softer materials may make use of a disposable protective sheet on the top of the stack to avoid unacceptable top sheet scratching.

As shown in this photo, FXB can be provided in a single table version or double table version, which permits a nonstop cycle. FXB's design makes unloading easy from the table's 3 sides.

table CNC's

CMS' patented ring pressing device

FXB - stacked sheet aluminum, double independent CNC controlled "ring pressing" device machining

In this photo, FXB is shown in a double table version and with double, independently CNC controlled, "ring pressing" devices, making it possible to machine completely different groups of parts from a stack of sheets on each table, if different orders have priority at the same time, or the same type of parts on both tables, for increased throughput volume. FXB's productivity and flexibility is also enhanced by its range of available table sizes, meaning that longer and wider sheet sizes can also be processed.

The photo to the left shows FXB's protective enclosure only in part for a clearer view of its "ring pressing" devices, the photo to the right shows FXB without its protective enclosure for a complete view of the system.


Ring Pressing Device on Moving Gantry

MBB - moving gantry with CMS' "ring pressing" device

MBB, CMS' moving gantry class CNC machining center, is shown in this picture with CMS' patented "ring pressing" device. MBB's format makes it possible to occupy a small floor footprint, while at the same time working with a wide range of sheet sizes and in a pendular cycle, depending on MBB's length, and permitting unloading from its sides and end.


Stacked Sheet Cutting Method

Stacked Sheet Aluminum - cutting method

As shown in this picture, CMS' patented cutting technology for stacked sheet aluminum is based on "micro tab" methodology. During the 1st phase, CMS' "ring pressing" device exerts a low pressure as the machining cycle takes place, so that the sheet stack is held together, not allowing any gaps between the sheets in the stack. During this phase, the majority of the machining takes place, and several "micro tabs" are left around the part perimeter so that it remains unmovable during machining, regardless of its size and shape. During the 2nd phase, the "ring pressing" device fixes itself at each "micro tab" in turn and exerts a high pressure, the ring being fixed, while the axes are left free to interpolate within the "ring pressing" device and machine away the "micro tab" with a movement of +/- 20 mm. At the end of this 2nd phase machining cycle, the parts may be removed from the sheet, there being no additional work to be done. CMS' "ring pressing" device has machined each part with a quality edge, high dimensional accuracy and a good surface.


Patented "ring pressing device"

CMS' patented "ring pressing" device

This photo shows CMS' patented "ring pressing" device on the left. The "ring pressing" device has 2 independent pressure phase settings as previously described, while at the same time, is capable of being fixed during the 2nd machining phase and allowing the axes to interpolate within the "ring" which is under high pressure. The "ring pressing" housing is designed to work with CMS' high velocity chip extraction system, so that chips don't accumulate during machining and interfere with surface quality. The "ring pressing" device also integrates with CMS' ATC system and high powered machining spindles, which results in high quality edge finishes, as seen in the photo to the right.


High Velocity Chip Extraction for pressing ring

Stacked Sheet Aluminum cutting & High velocity chip extraction

CMS' "ring pressing" device system incorporates high velocity chip extraction technology so that the large amount of chip waste generated during the machining cycle is moved out of the machining area and away from the sheet surface to reduce to a minimum the impact of chip scratching on the top sheet surface. Harder aluminum materials benefit from this and fall within the defined acceptable limits for surface depth scratching, soft materials will benefit from a disposable protective film applied to the top sheet.


 Nested parts cutting in stacked sheet aluminum

Nested parts cutting in stacked sheet aluminum

This photo gives an idea of the benefits of CMS' patented, "ring pressing," stacked sheet, cutting methodology. In the photo to the left, oddly shaped and small parts are seen nested in a stack of aluminum sheets. The parts have been successfully machined based on the CMS' low and high pressure cutting methodology with "micro tabs", resulting in perfect parts with high quality edges. The photo to the right indicates how the "micro tabs" have been machined during the 1st low pressure phase, which during the 2nd high pressure phase are removed at these locations and machined away, leaving the parts to be easily removed from the sheet at the end of the machining cycle.

 Examples of nested stacked sheet aluminum parts

Examples of nested stacked sheet aluminum parts

This photo shows examples of various parts nested in stacks of aluminum sheets. The upper left shows an efficient, high density, layout of a part with many holes around its edge. The upper right shows various parts as they came out from their stack in the sheet. The lower left shows a combined inner and outer plate part, while the lower right shows a heavier plate part with shape, slots and holes.

 Edge quality from stacked sheet aluminum cutting

Edge quality from stacked sheet aluminum cutting

A photo showing the resulting part edge quality from CMS' patented "ring pressing" device technology. At its corner, it reflects as if it were a mirror. The parts were machined from a stack of aluminum sheets 8 high.

 Aluminum deck plate

Aluminum deck plate

Aluminum deck plate is also machinable with CMS' cutting methodology. In this photo can be seen what is left of one of the small "micro tabs" after the part has been cut free from the nest.

Aluminum Stacked Sheet Layouts

Aluminum Stacked Sheet Layouts

This photo shows the opportunities for nesting and optimizing part yield in stacked sheet aluminum cutting. Small parts and large parts all go through the same machining process and are likewise removed as easily from the same sheet, with quality finish and dimensional integrity.

Very small sheet aluminum parts

Very small sheet aluminum parts

Even very small aluminum sheet parts, no bigger than a business card, have machining solutions as shown in this photo. CMS provides solutions for the range of machining processes.


Stacked Sheet Aluminum cutting

A double table FXB with CMS' patented double "ring pressing" device is shown machining stacks of aluminum sheets. Both tables are processing different nested layouts concurrently. The video shows the 1st low pressure machining phase in which the "micro tabs" are created and finishes with the 2nd phase in which the "micro tabs" are removed. The effectiveness of the high velocity chip extraction system, resulting in clean processing work, can also be seen, including the quality edge finish and good surface result.

CMS' FXB's productiveness, with its patented "ring pressing" device, can be measured as well by its output: 1100 parts in an 80 minute production cycle.

See the SPS case history study for more information.

Aluminum deck plate machining

FXB with CMS' "ring pressing" device is shown machining aluminum deck plate. The "ring pressing" cycle includes machining the perimeter with "micro tabs" and the 2nd phase to remove them.



Aerospace, CNC solutions
(click folder on the left to download)


Stacked Aluminum Parts Sector and SPS Case Study
(click folder on the left to download)