Expanded-capacity bar puller

Accudyne Products is introducing its expanded-capacity bar puller for CNC lathe automation. The new EZ-Puller Expanded Capacity supports larger round bar diameters of 0.093” to 2” (2.7 to 50.8 mm) and weights of up to 100 lbs (45.4 kg). Hex bar capacity of 0.25” to 1.375” (6.4 to 34.9 mm) and square bar capacity of 0.25” to 1” (6.4 to 25.4 mm) are pulled without the need for an M19 (spindle orientation) function.

The EZ-Puller is an auto-adjusting bar puller that enables the automatic operation of CNC lathes. Notably, the auto-adjust feature is driven by an ‘X’ value in the pulling sub-routine of a lathe program. This value represents the distance the tool needs to move in the X axis according to the bar diameter being pulled.

Accudyne’s patented design uses a cam and lifter system, where hardened steel grippers attach to hardened steel pivot arms. These arms have an integral cam lobe machined at their top. As the grippers advance over the bar stock, internal urethane springs compress. The urethane springs provide a reactive force that allows the grippers to securely hold the bar stock. This proprietary design provides optimal gripping force regardless of bar size or shape.

Other features of the EZ-Puller are that it will accommodate an infinite range of sizes within its capacity without mechanical adjustment, allowing for multiple pulls. Multiple pulls are used for longer parts that cannot be cost-effectively machined in one chucking. The design of the EZ-Puller also allows for pulling bars with minimal projection in front of the work-holding chuck. This characteristic allows the machinist to set-up with as little as two gripper serrations (0.12”/3 mm) of engagement, which makes for a more rigid set up.

For further information
www.accudyneproducts.com

Small quick-change interface launched

The Centrotex quick change-over interface from Hainbuch is now available in a new version for smaller machine spindles. Acclaimed by the company as the market’s smallest system for setting up clamping devices in a matter of seconds, the quick-change Centrotex S has a diameter of just 224 mm and offers repeatability better than ≤0.002 mm on the interface without having to re-align.

Hainbuch’s Centrotex S is a solution for eliminating non-productive downtime, set-up times and job changeover times that often increase when access to a compact work envelope is restrictive on operator movement and access. Featuring a fast change-over system and compact design, the Centrotex S eliminates excessive set-up times and is particularly suitable for compact machine tools with a small work envelope.

The machine adaptor mount on the spindle and the clamping device is equipped with a counterpart adaptor that can exchange with another clamping device in less than a minute. Actuation of Hainbuch’s Centrotex S is via just one radial locking screw, while ergonomic operation is now better thanks to the fewer rotations required to tighten and clamp the system. In addition, the Monteq changing fixture contributes to a faster clamping device set-up.

The new Centrotex S is suitable for clamping parts up to 52 mm diameter, and for A2-5, A2-6, AP140 and AP170 spindle nose systems.

Additionally, the Centrotex S system can offer a solution in fixed position clamping set-ups on the bed of machine tools. According to Hainbuch, the precision, rigidity and clamping forces can significantly improve machining performance, surface finishes and tool life.

For further information
www.hainbuch.com

All-round machining solution

Wiltshire-based Rotron Power, a specialist designer and manufacturer of rotary engines, has purchased a Lehmann T1-510520 CNC rotary table to support its machining activities.
“As we need to efficiently machine parts with demanding levels of precision, we have invested in a range of machine tools from XYZ,” explains production manager Sam Bellefontaine.

“When the need arose to purchase a rotary table, we were happy to take advice from XYZ’s technical staff and invest in a Lehmann unit. The machining flexibility and speed that our new rotary table delivers is now proving invaluable.”

Given the complex nature of many of its parts, Rotron Power would need to perform two or three separate machining operations prior to installing the rotary table.
“Now, thanks to the ‘all-round’ machining capability delivered by our Lehmann solution we can complete the same machining work in a single hit,” says Bellefontaine. “In addition, we no longer have problems related to the accurate relocation of workpieces for secondary machining operations. These factors have helped us to maintain our high precision standards and slash the machining time of many components.”

The relatively small footprint of the Lehmann rotary table means that, when mounted inside the XYZ machine, it occupies a minimum area of its bed.

“As well as leaving room for the fitting of additional work holding on the bed, the compact size of the rotary table means that – even when it’s not required – we can leave it inside the machine while other milling and drilling work takes place,” says Bellefontaine. “Also, when we are not using it, the rotary table’s low profile helps to increase the available working volume of the machine.”

For further information
www.lehmann-rotary-tables.com

Detecting defects and monitoring production

Two German firms, five-axis vertical machining centre manufacturer Wenzler (Heller group) and work-holding equipment specialist Roemheld, have developed a process that allows a casting or other component to be secured, while at the same time checking it for accuracy of form and position before machining starts. The solutions avoids adding value to defective workpieces that will later be scrapped, increasing process reliability, raising productivity and lowering manufacturing costs.

Wenzler conceived the idea as it wanted to offer customers, particularly those in the automotive industry, turnkey production centres for the reliable machining of aluminium chassis and suspension components, 24/7. The company’s technical manager Sebastian Knaus says: “We wondered how work-holding technology could contribute to making our customers’ production even more stable and efficient.”

Already familiar with Roemheld’s work-holding equipment, which he describes as “sophisticated, reliable, and sturdy”, he contacted the supplier’s key account manager Benjamin Nagel.

Development of the innovative clamping technology was based on a cast aluminium rear axle frame secured in a test fixture at Wenzler’s technical centre. The pilot phase ended in 2020 and this year it will find use assisting the series production of aluminium structural components at a German automotive supplier.

In more detail, the concept features swing clamps from Roemheld with integrated pressure sensors able to detect cost-effectively and easily the accuracy of the workpiece about to be machined. Intelligent clamping technology checks the parts for defects and contour variations, detects fixturing errors and provides information on the position of the component and the applied clamping forces during machining. Part quality is subject to continuous monitoring with seamless documentation.

For further information
www.roemheld.co.uk

Stable processes: reduced machining time

Question: “How long will it take to machine a part using your machine?” Answer: “I can quickly tell you exactly how long it will take by simulating the process in Vericut.” The dialogue is fictitious, but the scenario is realistic, not only because it is theoretically possible, but because Swiss machine tool specialist Starrag Group uses Vericut NC simulation software for this purpose. In addition to the verification and optimisation of NC programs, Vericut provides a precise indication of the run time of the optimised machining cycle.

Starrag Group develops, manufactures and sells precision machining centres with four, five and six axes for small to large workpieces, as well as gantry machining centres and vertical lathes for very large components, turning and grinding machines, associated software packages and special tools. Engineering and process optimisation solutions are also part of the company’s portfolio. Starrag solutions find use in aviation, power generation, transportation, precision engineering and medical technology. Headquartered in Rorschacherberg, Switzerland, the group of companies with more than 1500 employees has production sites in Switzerland, Germany, France, the UK and India, as well as sales and service locations in the most important customer countries.

Thomas Fink is head of application technology for machining centres at Starrag’s headquarters. Located on the edge of Lake Constance, the company has relied on Vericut as a solution for NC simulation for more than 30 years.

“The range of applications is very diverse,” says Fink. “We use Vericut in technology development for customer parts, conduct time and feasibility studies with it, and analyse customer programs in the event of problems or faulty machining.”

Machine-tool buyers naturally want to know what the machine is capable of in a specific application before they buy. So, as already outlined, Starrag builds a bridge to the future by means of NC simulation: the customer’s real NC program is checked for collisions on the virtual machine in Vericut, while the real process is digitised on the basis of the NC program, with the help of the machining centre’s digital twin.

Phillip Block, marketing manager of CGTech Deutschland, which distributes Vericut in the DACH region, classifies this process thematically.

“Vericut offers what Industry 4.0 is all about at its core: possibilities for high-level individualisation, potential for the intelligent production of equally intelligent products, and extensive integration of customers and partners into the company’s value creation processes,” he says.

Fink confirms it is exactly that kind of added value which can make all the difference these days: “As a full-range supplier of machine tools with technology support, it’s often necessary to know the machining times for customer parts as early as the quotation process, in addition to selecting the right machine. When implementing customer projects, the NC programs can be tested, analysed and optimised using Vericut before the real customer machine is even set up.”

The tools and clamping devices are also tested and optimised, which makes it possible to ensure – at a very early stage – that the process will run without collisions, travel violations or damage to the part. In this way, the safety factor as a mere snapshot of the present becomes a tangibly reliable expectation in the future.

Fink is not surprised “that most of our customers use Vericut for machine simulation”, and benefit directly from it. “Since our customers receive a digital twin of their purchased machine from us for pre-acceptance, they can check and optimise their processes even before final acceptance of the machine.”

Starrag as a machine manufacturer thinks in terms of product life cycles, so the use of Vericut even in the case of service is not surprising.

Fink states: “If problems occur during machining after the machine has been delivered to the customer, we are often provided with an NC program or a section of it. Thanks to Vericut, it is then possible to analyse this with very little effort, detect any errors or suggest optimisations.”

Of course, Starrag Group also uses Vericut classically in the simulation, verification and analysis of the NC programs with which Starrag Group manufactures parts for its own machines. Vericut, currently available in version 9.1.2, simulates the original NC code after the post-processor has run and detects programming mistakes such as rapid traverse errors or contour violations before real production. The software is sold in a modular format, so companies purchase only the capabilities they need. At Starrag, this naturally includes feeding Vericut with data from a central single source of truth.

“Due to close co-operation with various customers, Starrag uses several CAM systems,” says Fink. “For central management, a tool database is used that offers interfaces to all systems. The interfaces of the CAM systems to Vericut are also used.”

As one of the software’s early adopters, Starrag Group also uses Verticut Force, a physics-based module that analyses and optimises cutting conditions throughout NC program operation. The module delivers the most effective NC program for the given material, cutting tool and machining conditions.

Dirk Weiß, CGTech’s sales manager for Switzerland, among others, compares the Force application to conventional simulation: “Force is not about the milling strategies of existing programs; it also does not change tool paths. Material removal remains constant by adjusting the feed rate, and sub-dividing tool-path motions as needed to maintain consistent machining conditions for each tool. Everything is controlled by the feed rate: the geometries are not changed in the process.”

The result is significant time savings and improved cutting tool and machine life.

At Starrag, Vericut Force is used to optimise customer projects, design machine components and analyse NC programs in the event of tool breakage.

Fink says: “Tool breakages must be avoided, especially in demanding machining operations. The same applies to thin-walled parts, where avoiding deformation of the part due to excessive cutting forces is key.”

This sums up Vericut Force’s analytical potential to a tee: unsafe cutting conditions, excessive forces, metal removal rates, power, torque and tool deflections are graphically displayed during visual analysis of the NC program.

Lastly, Vericut Force pays off in optimising machining times so that customers have another competitive advantage with their Starrag machining centres.

Fink illustrates this with the example of a demo part for a stator segment: “The tool design, fixture design and CAM programming were completely checked in Vericut and optimised in Vericut Force. As a result, no time was wasted on prove-outs at the machine – the first part has already met the desired requirements in terms of surface and geometric quality. And all this with a 20% reduction in machining time.”

For further information
www.cgtech.co.uk