A project at the Centre for Fine Print Research (CFPR) is looking into a new approach to 3D printing. The emphasis is on stretching 3D printing by meaningful expression, not simple accurate piece-part reproduction of digital data. A flexible Mitsubishi Electric MELFA RV-7FLM articulated arm industrial robot is at the centre of the project.
Applications for Additive Manufacturing (3D printing) in manufacturing include prototyping and low volume production. It is also popular for making items with complex shapes that are difficult to replicated. The main challenge is complex geometry, as 3D printers have three axes (XYZ) and fabrication occurs in fixed horizontal layers. Fabricating an object requires breaking the shape down into a series of machine tool paths, then building up layers in a stable and reliable way. 3D printing is a very accurate process, both in the movement (steady acceleration and velocity) and the deposition of materials.
Stretching 3D printing
“Mitsubishi’s RV-F robot arm is very dexterous, allowing the robot to manipulate materials from all directions.” Says Dr Paul O’Dowd, Research Fellow – Creative Electronics and Engineering. “It has both freedom of movement and a comprehensive set of expansion capabilities integrated into the arm. This makes for an attractive combination of force control, movement range (908mm reach) and reliability.”
The artist can express something with the material, often pushing the material to its limits, for example by generating sweeping elegant forms, or revealing new material qualities, such as translucency. The CFPR has expertise in ceramics, photo-cure resins and thermoplastics and all are being investigated with the new robotic platform.
Stretching 3D printing in ‘unusual ways’ means moving beyond using CAD models using automated slicing algorithms Writing proprietary software makes it is possible to develop printing methods highlighting how the material can be expressively played with.
To achieve this shifted perspective, the project researches technologies and techniques to sense and manipulate materials in a dynamic way. “By pushing 3D printable materials to their limits, we have exposed unexpected properties in the materials,” . “For instance, manipulating plastic deposition whilst it is hot and pulled into hairs, or fine gauze, or woven.
Depositing ceramics means the material composition is capable of self-glazing in a single firing (as opposed to multiple firings). We can then conclude if these material states may have applications in wider industry.”
The task of robotically manipulating materials through complex states – for example, sensing and responding to viscosity – requires the integration of several advanced technologies. The MELFA RV-7FLM allows real-time control and provides a reliable programming interface to allow this to happen. It also has a large area of reach and movement for a compact robot arm.
Developing proprietary software reponds to changes in the material’s properties and the construction of the printed object. This means that the control program cannot be rigid in its operation. Instead it must interpret its working task environment and use the program to correct its behaviour.
What finally decided it for us was the affordability of the robot package and support provided by Mitsubishi Electric.