Germanys next Top-Modell

Long before a new car model hits the road, it can be seen and touched at a Bavarian model builder – at least, if it weren’t top secret. The experts sculpt whole vehicles from aluminium blocks as 1:1 models for many OEMs. Thanks to intelligent zero-point clamping technology from AMF, aluminium blocks weighing multiple tonnes are cut with strong process reliability – fast, flexibly, and with repetition accuracy.

One model builder has introduced a consistent zero-point clamping system on all necessary machines in his production operations. With AMF, he has a competent partner that understands its customers’ challenges and develops customised solutions from standard products. This makes it much easier to perform complex cutting operations on raw aluminium blocks for individual parts or small series production. Long setup and calibration times are a thing of the past.

Clamping and set-up processes simplified and accelerated

When finished, the 1:1 scale model actually looks like a real car, just made of aluminium. Even the doors and boot lid can be opened. And it even sits on aluminium rims. And so the designers and engineers can make an initial three-dimensional image of a newly planned car model and actually walk around it. The final aluminium model can later be found on the assembly line as a test and gauge model.

Small powerhouses grip things safely

The aluminium blocks for individual parts, such as floor assemblies, side parts, roofs, boot lids and wheels, must be clamped exactly and then worked on precisely on huge gantry milling machines. Two work tables measuring 1300 x 2000 mm and two measuring 1300 x 1000 mm as well as additional one are used in the Jobs LinX machines. They are equipped with 50 or 20 K10 zero point installation clamping modules from AMF at intervals of 200 millimetres. With a defined grid pitch, each work table offers the greatest possible flexibility for positioning the elements.

As simple and logical as Lego

On the work tables with integrated zero-point clamping modules and cross-T slots, the workers place modular spacer elements on top of each other until the block or unmachined part reaches the height where five-sided machining is possible. The clamping can be planned in advance just as easily as with a Lego building kit. The AMF assortment of connecting, construction and counterbalance elements as well as various adapters is almost inexhaustible. The upper interface to the workpiece is again a mechanical zero-point clamping module K10, which positions and clamps the M8 or M10 pull-studs screwed into the workpiece in a process-reliable manner. The system is as simple and logical as Lego. Everything fits together and, thanks to zero-point clamping modules, can be placed quickly and exactly.
The clamping modules are opened hydraulically with an operating pressure of 60 bar. Each one pulls in the correct pull-stud with ten kilonewtons and then holds it tightly with 25 kilonewtons. The modules do this with repetition accuracy and a precision of better than 0.005 millimetres (<5 µm). Since they are mechanically locked by spring force and so tensioned without pressure, the pressure lines are removed after the clamping operation.

Collision-free 5-sided machining thanks to direct clamping

For direct clamping, the holes necessary for the pull-studs are made directly in the unmachined part or aluminium block. The design engineers plan for that from the start. AMF provides CAD data so that later machining operations run without disturbing contours or collisions.
The machining performance is great. Up to 40 hours of machining time come together. All in all, aluminium blocks of various sizes, totalling around 20 tonnes, are required for a vehicle. In the end, a new car model stands there in original size long before it hits the road. For car manufacturers, this is an indispensable part of a new model’s development phase. Developers recognise early whether the car meets their expectations. In any case, AMF clamping technology meets their expectations with certainty.