Cronus - Moving Bridge

Cronus K - CMS' compact, yet highly powerful, precise and versatile 5 axis CNC milling and machining center…

CMS' Cronus K - the compact, yet highly powerful, precise and versatile 5-axis CNC milling and machining center.

The Cronus K enjoys all the features of the Cronus range, but on a Monobloc basement with a compact working area:

• Guide ways mounted directly to the Monobloc structure
• Working area formats available either in 2,600 x 1,500 mm or 4,000 x 1,500 mm versions, with a Z stroke of 1,300 mm
• Maximum axes speeds up to 85 m/min with extremely fast acceleration
• Supplied with CMS' Torque 5 machining head with a power of 28 kW S1 rating at 12,000 rpm, maximum 24,000 rpm, B axis range +/- 110°, C axis range +/- 300°, having quick positioning speeds of 36,000°/minute. Cronus K offers waste extraction solutions for all process machining requirements and is available in dry, mist or full flood cutting versions:
• Dust collection - When dry machining composite materials, with 5-axis dust hood extraction available
• Waste chip extraction via belt conveyor - For heavy chip volumes when machining dry or with oil mist Waste chip extraction systems, complete with cutting fluid capturing, filtering and recycling

CMS' Cronus - a first look

The CMS Cronus CNC mill showing its robust, heavy duty structure designed and created through FEM technology (Finite Element Method). This Cronus shows the protective walls placed between Cronus' solid support shoulders, with rear protective interlocked doors closed and those at the front open.

To the right is shown the FANUC 31i controller with its "nano" precision technology, including the complete FANUC control package for drives, servos and axes communications' infrastructure.

In the center of the picture is the heart of Cronus' machining capabilities - its movement and machining structure. The heavy oversized bridge structure is placed upon an equally heavy pillar and shoulder construction, which are mated with heavy duty roller bar bearings "tank track" type, successfully implemented only upon structures designed for such stresses. The Cronus 5 axis CNC machining center's uniquely designed heavy carriage supports its rigid mast structure and the special Torque 5 (28 kW) working head, completing Cronus' range of high power, performance and precision needed for today's Advanced Materials applications.

This Cronus is also supplied with a cast iron T-slot table for securely anchoring the fixtures and parts to be machined on it, providing a foundational element in the chain of its outstanding performances.

Cronus in its ready to work condition - and view from the side

Cronus CNC mill in its ready to work condition. With Cronus' protective, interlocked doors closed in the front, it's possible to see the many rigid, heavy, support pillars along the side of the machine and the large cross section shoulders mounted on top of the pillars.

Cronus' protective wall system and doors with viewing windows provide a safe and unobstructed enclosure for the operator to work with the machine at all times in complete safety.

Cronus double bridge version

A Cronus, 5-axis machining center, large work envelop, double bridge version with Torque 5 working head on each bridge is shown here, specifically configured for work in the Aerospace industry. Here again from the side of the machine can be seen Cronus' massive pillar and shoulder construction with its large cross-sectioned, oversized, bridges on each of which a Z mast is mounted.

Since this Cronus has 2 bridges, each of them is designed to work independently of the other, so that a completely independent cycle can be executed at the same time on both ends. Regardless of the machining cycle time and the differences in work to be done, the work continues unhindered at either end of the machine. This Cronus also has a central protective divider in the machine envelop so that loading and unloading can take place in one zone, while machining operations are taking place in the other zone. The protective entry doors on either end are configured so that the operator may open them only when machining operations in that zone have finished, while entry through the door on the other end is still restricted and secured.

Cronus double bridge machining center at the Daher-Socata with CMS' UHF tables

Photo of the Cronus double bridge 5 axis CNC machining center at the Daher-Socata company, aerospace manufacturer for wing skin surfaces for Airbus and other components. This version of Cronus is shown with CMS' special UHF table (Universal Holding Fixture) designed with Passively Activated Pods. The fixture is shown holding a wing skin surface that will be machined with additional requirements including removal of paint from metal bushings to permit conductivity of static charges away from the wing surface and drilling of countersunk holes based upon the real location of the surface in space and not just the theoretical position indicated by the program.

CMS' UHF table makes possible not only the location of the pod to its required precise height, but also its inclination and rotation in relationship to any curved surface, as shown in this picture. Once each vacuum pod is located in its precise, required location under CNC control it is locked in position and will not move. The UHF table also provides for part referencing, all done automatically and under CNC control.

The Daher-Socata Cronus illustrates CMS' concern and commitment to provide solutions for manufacturers working with Advanced Materials and their unique requirements.

Cronus with a expanded length and height - a massive work envelop

Cronus CNC mill with an expanded length and height used for machining various large composite components: as for example, this large composite bridge element. Cronus here is shown with an expanded length of 31 meters (101.7'), providing a very large work envelop capable of machining truly large structures. Notice the proportion of the operator to the height of the bridge and the mast for an idea of the massive size of Cronus' work envelop. In addition, a special precision fabricated work table has been provided. An overhead crane makes easy work of moving these large heavy elements through Cronus' work process.

Complete environmental enclosures are also available for Cronus…

A complete environmental enclosure is also available for Cronus.

On the left, the Cronus vertical machining center is shown with a total enclosure, enclosing the machine on all sides, including the top. The full enclosure for Cronus has provisions for entry of natural light, control of the doors on both ends, a high flow total dust extraction system to remove harmful and irritating particulate from the air, noise deadening panels, internal lighting controls, and optional equipment for fire control.

On the right Cronus is shown with a retractable roof enclosure to provide for total enclosure against harmful and irritating particulate. Cronus' retractable enclosure is attached to each side of the bridge and expands and collapses like an accordion as the bridge moves in either direction. Cronus can also disengage the roof, as needed, making it possible to load and unload from above.

Cronus' "arc" of enhanced performance

Cronus - enhanced performance…

Moving around, the Cronus CNC mill's enhanced performance "arc" can be seen:

• Cronus' heavily augmented basement: supporting pillar width increased by 220%, number of pillars increased by 140% significantly reducing the opportunity for linear elasticity during the moment of bridge passage
• Cronus' rectilinear movement regulation capability doubled, resulting in guaranteed straightness
• Carriage structure for Z mast: a heavy fabricated box structure with one-piece inserts for slide blocks, with a resulting increase of flexional rigidity in the YZ plane assuring straightness of movement of the Z axis mast
• Mechanical thermic expansion compensation system for the bridge: nullification of bridge deformation, correct movement of recirculating roller slide blocks, and nullification of basement geometric deformation
• Double servo-motorization on the X and Y axes: The servomotors work as a matched pair creating opposing movement which permits the complete nullification of inversion backlash and a more structurally rigid movement
• Recirculating roller ways (tank track type) with integrated direct measurement system
• Z axis mast structure: augmented dimensions conforming with direct motorization requirements as well as internal structural components
• Moving bridge: augmented dimensions of the internal structural components, welding cross section increased and positioned continuously on both sides of the plate, improvement in the relationship of flexional stress and torsion obtained from increased cross sectional dimensions Torque 5 working head: Birotational working unit with direct motorization.

Torque motor technology can be conceived of as simply a linear motor rolled up. Torque motors are synchronous servomotors permanently excited, with the following characteristics: very fast oscillation movements, elevated dynamic, elevated rigidity in static position, usage independent, elevated torque, without backlash, no wear parts, elevated positioning precision, and, additionally, CMS has added Torque 5's automatically activated powerful braking system for each axis when not being interpolated to further increase the system rigidity, highly rigid radial-axial bearings, rotating absolute encoders, and liquid cooling system for the direct motors

As can been seen, the Cronus 5 axis CNC machining center’s engineering is a complete, well thought out system of balanced and enhanced performance objectives, meaning that every part of the system is designed for optimum performance and no one point has been overlooked to become the "weak" part of the system.

Cronus' enhanced and oversized basement

In this photo can easily be seen Cronus' oversized pillar width, reduced light between the pillars and massive shoulders upon which are mounted, in this case, a pair of equally massive moving bridges.

Cronus' double servo-motorization

Here beneath Cronus' bridge can be seen one of the pairs of servomotors used on the X and Y linear axes. This servomotor set works as a matched pair to create opposing movement and provide for the complete elimination of backlash, which occurs from axis inversion, as well as providing an elevated structurally rigid movement.

Cronus' Y axis carriage with mast

A photo of Cronus' Y axis carriage supporting the Z axis mast. Here is seen Cronus' thick, heavy, fabricated box structure carriage designed to improve flexional rigidity in the YZ plane and to assure movement straightness of the Z axis mast. In addition can also be seen the same double servomotor pair on the Y axis, as on the X axis, eliminating backlash and dramatically increasing the rigidity of its movement.

Cronus' compensation system for thermic expansion

Cronus CNC mill's enhanced compensation system for thermic expansion forces, resulting in the nullification of bridge deformation, correct movement of recirculating roller slide blocks, and nullification of basement geometric deformation.

Cronus' important characteristics

Most of Cronus' important characteristics are seen in this photo. Located in a large American Aerospace manufacturer, this Cronus 5 axis CNC machining center is nearing the end of its installation. Here again is easily seen Cronus' oversized pillars with reduced light between them, its robust, heavy shoulders and massive bridge with oversized carriage structure and Z mast, the pairs of opposing servomotors cancelling out backlash, its heavy rack and pinion system, guide ways with roller bar bearings (tank track type), and in addition a specially fabricated precision work table installed in the floor.

Cronus' Torque 5 head - important features

This photo shows the basic composition for the Cronus CNC mill's Torque 5 head and the location of the: direct drive motors, special braking system which engages and disengages automatically when the Torque 5 axes are not interpolating, its axial-radial bearings, direct encoders reading the scales on each axis, and fluid joint through which cutting liquid, or even compressed air, is made available during cutting processes though the cutting tool body.

Cronus' Torque motor, direct drive, can essentially be considered a rolled-up linear motor; direct drives are also permanently excited synchronous servomotors, all of which gives it the following advantages:

• extremely fast rotational movement
• high dynamics
• high static stiffness
• without component parts subject to wear
• high torque
• no backlash extreme positioning accuracy capability

Cronus' Torque 5 spindles

Cronus' Torque 5 head has 3 standard spindles available:

• Power of 15 kW (20 hp) S1 (12.1 Nm) rating at 12,000 rpm - Maximum speed 24,000 rpm - HSK63E connection - Liquid-cooled, ceramic bearings front and back
• Power of 28 kW (37.

5 hp) S1 (63 Nm) rating at 4,300 rpm - Maximum speed 18,000 rpm - HSK63A connection - Liquid-cooled, ceramic bearings front and back

Power of 28 kW (37.5 hp) S1 (63 Nm) rating at 4,300 rpm - Maximum speed 24,000 rpm - HSK63A connection - Liquid-cooled, ceramic bearings front and back

Cronus' Torque 5 head for dry cutting processes

The Cronus vertical machining center's Torque 5 head for dry cutting processes is available with a CNC controlled dust hood that opens and closes via m-code executed from the program. In the picture to the left the dust hood is shown open so that a tool change can take place, or even to permit holding an aggregate. In the picture to the right the dust hood is shown closed, allowing it to pick up dust generated during the cutting process. Extracting dust from near the tool's cutting tip in 5 axis machining can be difficult due to the chip speed and proximity of the dust hood to the tool length. If tool length is significantly greater compared to the dust hood length, CMS also has available an automatic dust hood changing solution making it possible to change to a dust hood that optimally matches the cutting tool's length.

In many 5 axis cutting situations, one of the best overall solutions for dry 5 axis cutting is a CMS total enclosure with down draft for complete control and containment of all dust.

Cronus' Torque 5 - full flood capability and mist too

Cronus' Torque 5 heads also come available with full flood capability, so that the cutting tool is constantly receiving a fresh supply of cutting fluid. As was mentioned, the Cronus CNC mill is also available with a fluid joint, so that, if needed, cutting fluid or liquid can be channeled through the body of the cutting tool.

To complete the available cutting options, Cronus can, as well, be supplied with mist cutting capability.

Cronus 16-place tool rack

Shown in this picture, Cronus comes with a standard 16-place, lateral pick-up tool changing magazine placed on the ground, left side of the machine (on center distance of 110 mm between tools) and a selection of HSK tool holders. The Cronus vertical machining center can also come with an optional second 16-place rack.

Cronus 30-place tool disc

As an option, Cronus has available 30-place tool carousels (on center distance between tool holders 80 mm). In the picture to the left the doors to the tool changing magazine have been opened, the carousel has been extended into the work area and the Cronus 5 axis CNC machining center is shown picking up a tool from the disc with its dust hood open. In the picture to the left the tool changing magazine is shown from the outside of the machine with the carousel door open where the operator can change tools without entering the work zone while the machine is running.

The UHF table (Universal Holding Table)

In this photo, Courtesy of DAHER-SOCATA, manufacturer of wing skins for Airbus and other aerospace components, the UHF table can be seen (Universal Holding Fixture).

The UHF is CMS' flexible tooling system. UHF tables are based on the Passive pod activation concept as opposed to Active pod activation. Although the Active approach of setting the pods is certainly interesting, in reality it also has several draw backs. Here are the primary benefits of CMS' Passive pod activation, UHF table:

• Each pod is individually set under CNC control by Cronus. The pod rises from its holding position, Cronus meets it and adjusts it to its precise height in the process, at which point the pod shaft is pneumatically locked in position. Following this, in one controlled CNC motion, both the inclination and rotation of the vacuum pod is carried out by Cronus and both aspects are locked in their precise position pneumatically. The Active pod system does raise all the pods to the correct height at one time, but the rotation and inclination must be set manually for each individual pod according to the skin curvature, which in the end takes even more time due to the operator's required manual intervention and results in less verifiable precision of pod location.
• Each required reference location is set by the Cronus CNC mill and each pod may become a reference location as needed. The Active pod system only permits a certain number of fixed locations without flexibility.
• The Passive pod system requires much less electronic mechanism and much less cost while providing a quicker, more accurate setup without operator intervention in the end.
• Cronus' UHF table, in general, makes it possible to eliminate the need for making and storing complex fixtures. The UHF table makes updating and changing specific elements in a project simple and predictable.

Cronus' UHF table consists of a matrix of 99 passively activated vacuum cups (positioned at differing centers to provide the optimal layout for large and small parts); each cup is 85 mm in diameter and has a vertical stroke of 700 mm. The vacuum cups can be positioned at +/- 45° from horizontal and rotated throughout a full 360° in the XY plane. The UHF pod matrix covers an area of approximately 3.5 meters x 2.0 meters and allows for multiple datum points which can be automatically changed by the machine to suit the customer’s requirements, thus offering maximum flexibility and ease of use.

Cronus adjusting a passively activated pod

Here Cronus is shown making an adjustment under CNC control to the inclination and rotation of this passively activated pod. The precise height adjustment of the pod has already taken place and its shaft was pneumatically locked into its required location. Now Cronus rotates and inclines the pod, completing the setting for its required location in space under CNC control and the UHF table locks these final adjustments in place pneumatically.

UHF table setting referencing locations

In this photo the UHF table can be seen with a group of pods already set for their height, rotation and inclination. Now the Cronus CNC mill is placing referencing elements in specific pods to provide the necessary location points, allowing the wing skin to be easily positioned for the machining cycle to begin.

Composite wing skin ready for machining to begin on the UHF table

In this picture, courtesy of DAHER-SOCATA, a composite wing skin is seen, ready for machining to begin. The passive pod matrix has been completely adjusted under CNC control by Cronus for correct height, rotation and inclination and all the reference points have been set. Since this is a Cronus with two completely independent work zones, entirely different work cycles can take place concurrently, including setting the UHF table, loading and unloading operations.

Cronus' special aggregate for paint removal and conductivity testing of wing surface bushings

The Cronus 5 axis CNC machining center is here shown having picked up a specially developed CMS aggregate used to remove paint covering the metal bushings in the wing surface after a finishing process. The aggregate rotates a blade edge to remove paint built up on the bushing surface of the wing. During this process, the aggregate also executes a conductivity test to verify and confirm that the surface is free of paint and capable of effectively drawing off the static surface charges that build-up during flight.

Cronus' solution for routing countersunk holes on wing surfaces not conforming with the theoretical data

Composite wing surfaces require many accurately machined countersunk holes. Thin sectioned curved composite surfaces, typical aerospace parts, present unique machining challenges which are often associated with wing skin panels, such as: deflection under clamping and drilling operations, and small geometric data errors. CMS' engineers provided the Cronus CNC mill with a unique solution involving the use of a precision measuring device to control the actual depth of the countersink from the wing skin surface.

Here Cronus is equipped with a special machining head, type PX5 with 40,000 rpm spindle, capable of general machining processes as well as the routing of each countersunk hole location orthogonal to the wing surface. For each hole Cronus carries out the routing and countersinking process at the correct depth regardless of the fact that the real position of the skin surface may not be where the theoretical CAD/CAM data places it; the resulting countersunk hole is without edge-burr and blowout, and it has all been done in one continuous process without the need of prior scanning of the surface.

As seen in this photo, Cronus' machining head also comes equipped with CMS' 5-axis universal dust hood.

Cronus' tool storage disc and laser measurement device

Completing the Cronus' solution with the UHF table is its tool storage disc for automatic tool changing, which during tool changing operations moves out into the work envelope from behind a pair of dust protection doors. Just to the side of the tool changing disc is seen a laser device for measuring cutting tool length and for automatically updating the tool data in Cronus' controller. In addition, it provides for broken-tool detection, in which case Cronus commands that the tool be changed out for a fresh one, then continues on with the machining cycle.

Advanced milling methodology used on aluminum wing spars

In this picture the milling spindle used on Cronus is shown - 28 kW (37.5 hp), S1 rating at 4,300 rpm, maximum 24,000 rpm - in a high speed milling routine machining a thick aluminum plate to produce a wing spar. The full flood cutting methodology mills away per HP about 4 cubic inches of aluminum per minute, while the chips can be carried away on a chip take away belt and the cutting fluid captured, filtered and recycled.

The advanced cutting methodology makes it possible to rough out the large amounts of aluminum plate that must be removed as chips during the machining process, while at the same time obtaining the finish milling of the wing spar "rib." This process yields increased productivity, while delivering high level accuracy to obtain smooth "rib" wall surfaces, resistant to stress and fracture.

In the picture on the left the full flood milling process is taking place and in the picture to the right a better view of the tall "rib" structure on the wing spar can be seen.

CMS, Scaled Composites and SpaceShipOne

CMS is proud to acknowledge its partnership with a truly unique and leading company in the composites industry, Scaled Composites. Their purchase of one of CMS' first Poseidon machining centers laid the foundation as the predecessor for today's enhanced generation of Cronus CNC milling and machining centers.

In the picture to the left is seen Scaled Composites' SpaceShipOne, winner as the first non-governmental entity–a private company–to launch their vehicle SpaceShipOne into outer space, return it to Earth, and do it again within two weeks. This was a truly amazing feat of engineering and determination from this unique group of American historic pioneers.

Among the following are highlights of SCALED COMPOSITES government, commercial and purpose built projects which they have completed over the years: Adam M309, Ares, ATTT, B2 Model, DCX, Bell Eagle Eye, Freewing, Global Flyer, GM Car Pegasus, Proteus, Raptor, Roton, SpaceShipOne, Triumph, V-Jet II, Vantage, Voyager.

More about Scaled Composites and their first Poseidon can be found on their website: http://www.scaled.com

In the picture to the right is seen one of CMS' first Poseidons installed at Scaled Composites in 2004.

CMS, Scaled Composites and GlobalFlyer

Among the amazing engineering and developmental frontiers in composites history is that of GlobalFlyer, marking another historic step for Scaled Composites and another reason why CMS is proud to have provided Scaled Composites one of its first generation Poseidon machining centers, the forerunner of today's enhanced performance Cronus.

Here are the basic facts about GlobalFlyer provided courtesy of Wikipedia:

"The Scaled Composites Model 311 Virgin Atlantic GlobalFlyer (registered N277SF) is an aircraft designed by Burt Rutan in which Steve Fossett flew a solo nonstop airplane flight around the world in a time of 67 hours 1 minute from February 28, 2005 until March 3, 2005. The flight speed of 590.7 km/h (342.2 mph) broke the Absolute World Record for the fastest nonstop unrefueled circumnavigation set by the previous Rutan-designed Voyager aircraft at 9 days 3 minutes and an average speed of 186.11 km/h (115.65 mph).

"The aircraft was owned by the pilot Steve Fossett, sponsored by Richard Branson's airline, Virgin Atlantic, and built by Burt Rutan's company, Scaled Composites. The companies had previously announced a combined effort for Virgin Galactic.

"Between February 8, 2006 – February 11, 2006, Fossett flew the GlobalFlyer for the longest aircraft flight distance in history: 25,766 miles (41,467 km)."

http://en.wikipedia.org/wiki/Virgin_Atlantic_GlobalFlyer

Cronus - machining Modular Composite Bridge components

The Cronus CNC mill shown here, at Seemann Composites, has completed its initial assembly and is in a testing routine after which it will be enclosed with its wall protection system. As the picture shows, this Cronus is very long, 31 meters (101.7') as well as wide and tall, perfect for large heavy, demanding parts like this Modular Composite Bridge component. Cronus not only provides a work envelope capable of handling such a large part, but is equally able to provide the accuracy and power that's needed as well.

Seemann Composites, founded in 1987 by Bill Seemann, is known for its patents in composite engineered materials such as C-FLEX, a composite material providing racing dominance in the yachting world for many years, and SCRIMP, a fundamental technology of vacuum infusion, as well as its ability to provide important research, development and engineered products for a range of well known companies, including the US Department of Defense.

In the photo can be seen a section of Seemann Composites' Modular Composite Bridge (MCB). The following information is courtesy of Seemann Composites.

"The Modular Composite Bridge (MCB) Program was a logical follow-up to the successful Composite Army Bridge (CAB) Program. The primary focus of the program was the development of structural bridge joints that would enable modularity and reconfiguration of the composite military bridges. The program culminated with the successful fabrication and testing of two joined seven-meter (full length) bridge treadway sections. The joined bridge sections were initially subjected to 1,000 fatigue cycles of 100% Proof Load and then loaded to their ultimate capacity of 166% Proof Load (approximately 750,000 lbs.), surpassing the MCB goal of 150%..." http://seemanncomposites.com

Cronus - machining composite aerospace components

In this photo one of Embraer's Cronus machining centers is shown. Embraer is known worldwide as a major supplier of Commercial Jets, Executive Jets and Defense Systems Aircraft. CMS has been privileged to work with Embraer for some years now for the improved processing and cost reduction in the manufacturing of their composite aerospace components. About 10 years ago Embraer introduced the use of advanced material composites into their product line. At that point their production was based on traditional CNC machines for metal. Embraer's choice of the CMS Cronus was based on its need for higher productivity, faster return on investment, and a larger working envelope with a pendular (non-stop) cycle capability. Cronus provided all this and resulted in a 33% reduction in cycle time and a 70% reduction in machine cost per part produced, as well.

More information about Embraer, the company and its products, can be found on its website: http://www.embraer.com

Cronus K machining cockpit windows in aerospace applications

Cronus K CNC mill is shown here machining an advanced materials cockpit window in a full flood mode for use in one of today's new generation aircraft. The special laminated advanced materials used for these window applications range up to a thickness of 1.75". Cronus provides the high power and torque, accuracy and quality of resulting edge needed for this critical application. Cronus' Torque 5 spindle machined the 1.75" thickness at less than 25% of its full load capability.