The company, based in Ense-Parsit, Germany, use specialist tools on their 40 eccentric and 17 hydraulic presses which manufacture inserts with a pressing force of up to 6000 kN. In addition, they have 18 stamping machines with a pressing force of around 4000 kN. These are provided with steel strips up to 6 mm thick, and coils reaching a width of 800 mm. In subsequent production steps some of the batches are deburred with others being spot-welded or TIG-welded. This is, for example, how complex formed furniture fittings, pre-finished frames for sliding roofs in cars, and complete impellers for fitness trainers, are created.

Managing Director Franz-Bernd Pauli says: “Our greatest strength is working closely with customers from the start of a project right through to series production. This includes the prototype development and our expertise in tool making. It’s important to have a consistent software solution enabling us to react quickly, flexibly and smoothly at every stage, right through to completing the production-ready tool.”

When Stefan Schmitz joined Franz Pauli he felt the parametric system previously used by the company was ideal for mechanical engineering, but not for tool making. “Switching to VISI has proved to be a huge step forward as it is tailored specifically for tool making, offering all the functions we need in the sheet metal industry.”  That consistent sector-orientated alignment, coupled with its milling strategies and EDM functionality, along with technical support from VISI reseller MECADAT, led to the company to transfer completely to VISI. Currently, Franz Pauli are running three CAD workstations in the design office and a full CAD/CAM workstation in the production area with 2D, 3D milling and Wire EDM.

“As a combined surface and solid modeller, VISI supports me as a tool designer with detailed tailored functions and automated algorithms for the design process. When I use VISI I can always focus on the entire tool, as it doesn’t have a complicated parametric structure. This means I can be much more flexible without worrying about the assembly hierarchy. For example, if I do want to work on the details I can always thin out the tool.”

But VISI proves its worth even before the contract has been won; at the quotation stage. “At this point the 3D CAD model of the customer’s part is nearly always available. Regardless of the native CAD format, we can import into VISI and check out the dimensions. Then I create a blank, position the strips and determine the strip width. From this, we calculate the cost of both the tool and the part.”

He says the blank then forms the basis for the pre-calculation of the tool, and he uses the method planning later for the full tool design where the 3D strip layout is constructed using VISI Progress, and is passed to the bending station, where the tool is constructed.

Once the tool has been designed, the strip layout is updated using the bending and drawing stages. “VISI makes it easy to try out different paths to find the optimum process. I can graphically animate the forming process, making it easy to assess material wrinkling and thinning, highlighting any possible fracture points.”

The parts making up the tool are measured against the 3D CAD model, and the final blank is created in the tool by wire erosion. The tool is then brought to the press, measured again, and if tolerances have been maintained, production begins.

Technical Manager Oliver Fischer, who is responsible for the CAD strategies, says that as design engineers no longer stand at the milling machines, the operators must also be able to understand and operate the system. “VISI is so easy to use – which I consider to be another great strength.”

Each machine operator creates the NC programs in the tool making department, and uses VISI Machining to establish which components will be brought together in one process. “As VISI uses the same CAD model for design and NC programming, the data’s consistency and interoperability is guaranteed. This is a major advantage for the actual programming and if any modifications are required – two significant aspects of tool making.”

The software also plays a key role on the shopfloor with VISI’s Compass Technology generating considerable time savings. Automatic feature recognition algorithms independently detect regular geometry such as edges, holes and milling pockets, then automatically generates the necessary NC data, maintaining company standards and ensuring proven manufacturing methods.

Franz-Bernd Pauli concludes: “The VISI philosophy of a ‘one source solution,’ coupled with its ease of use, and the functions its modules provide for tool design, and which are precisely co-ordinated to the sheet metal area, play a significant role in us being able to respond even faster and more flexibly to today’s demanding customer requirements.”

For the cranial implant, surgical grade titanium powder particles were used, bound at a molecular level by a high intensity laser, generating a compact, robust and biocompatible structure. The 3D printing was carried out on an EOSINT M280 DMLS (Direct Metal Laser Sintering) machine valued at around US-$1.5m. Printing directly from the CAD data, the machine is equipped with a 200 W or 400 W fibre laser which melts fine metal powder and builds up the product layer by layer. This method produces extremely complex geometries that could not be manufactured using traditional methods.

The prosthesis was designed using the VISI CAD/CAM suite from Vero Software, and undertaken free of charge by designers and engineers from Vero’s Mexican reseller, VISI Series México. The team comprised Raúl Moreno, Salvador Enriquez and Elĺas Hernández.VISI Series México collaborated with the Advanced Human Bioengineering Foundation for Latin America (BHA Foundation) to make this important technological breakthrough possible.

The original STL file of the entire head was provided by the medical team and was produced by the CT/MRI scanner. The STL file was used to 3D print an internal plastic prototype model to analyse the shape of the hole. Working with the doctors, the prototype model was reworked to create a nicer uniform hole with no fragments. Once happy with the topology of the skull, the prototype model was scanned and imported into the VISI CAD application.

From there, a network of curves was taken from the good side on the skull and mirrored onto the left side to cover the aperture. Then a surface model of the prosthesis was created and the doctors were again consulted to help determine the ideal fixing structure and screw locations and to ensure that the model conformed to the needs and complexities of cranial anatomy. At this point, a plastic prosthesis was printed for assembly to the head prototype to check for alignment and fitting. With a design finalised, the prosthesis was sent to the USA for printing on the EOSINT M280 DMLS machine. The US-$8,000 printing costs were met by a private company in Querétaro, with the support of the BHA Foundation.Project Director Dr Gilberto Lopez – a specialist in oral and craniofacial rehabilitation – worked with experts in neurosurgery and maxillofacial surgery, regarding the cranial implant design, and successfully prepared the surgical titanium prosthesis model.

Commenting on the prosthesis design, Elĺas Hernández says “We worked closely with the medical team to perfect the design. The holes and fixing structures all serve a purpose. It was important that the design would interact naturally with the human body, allowing fusion of bone tissue and fluid flow within the cranial cavity. Because the prosthesis is metal, it must also allow for low heat dissipation around the brain.”

Lasting four hours, the surgical procedure was carried out at a public hospital in the Mexican city of San Luis Potosi, by a team of neurosurgeons, maxillofacial surgery and oral rehabilitation specialists, who also worked free of charge.

Raúl Moreno, Director General at VISI Series México says: “A number of countries, including England, the United States, China and Spain, are already starting to use this type of technology for patients with congenital or acquired craniofacial deformities.

“The process gives the ability to design and manufacture custom prostheses quickly and safely, which are both functional and aesthetical, considerably improving the patient’s quality of life. And Mexico is now finding a position amongst the pioneers of custom titanium prostheses. The fact that a group of technicians and physicians can selflessly contribute in this way to benefit our society is a great source of pride.”