K Hall 10, Stand E55; Motek Hall 3, Stand 3221
What if, when building your own home, you were able to create custom concrete parts that exactly fit your needs and, in the end, reduce CO2? How to do that, knows the start-up Print Stones: With his mobile 3D printer, individual concrete parts can be created on site at the construction site. The necessary flexibility is provided by a familiar way from industrial automation Tool changing system from Gimatic.
The Viennese start-up Printstones has been dealing with automation in the construction industry since 2017. The focus is on the development of an 3D printing process for the automated and site-ready production of concrete objects, which attracts attention with two unusual features: It is mobile and prints concrete as well as other cementitious materials that are used on the construction site. Conventional formwork elements are now a thing of the past.
Dr. Herwig Hengl is the founder of the spin-off of the Vienna University of Technology. About five years ago, he came into contact with additive manufacturing for the first time as an employee at the Institute of Mechanics of Materials and Structures: "We came up with this idea when we developed a simulation tool that can be used for stress and strain analysis of stressed components. To verify the simulation results, the virtual components had to be rebuilt and loaded. As this is a very costly and time consuming process, we were looking for a way to automate parts directly from 3D models, "recalls the young entrepreneur. Ideally, this should of course take place directly at the final site: at the construction site of the future.
The Printstones founders were able to prevail with their business idea against about 200 other start-ups in a selection process of the university incubator INITS. As a result, the business model was validated by means of qualitative and quantitative experiments and the development of the "Printstones X1" was launched.
Potential application in own thing
Gimatic Vertrieb GmbH supplies the tool change system for the 3D printer. The Hechinger had always been open to unusual and not straightforward mass applications.
In this case, managing director Johannes Lörcher even sees an application in his own right: "The 3D printing is very much on the rise and you are always reading more about new developments for the construction industry. I think the idea of printing bricks is great - even though the printing of bricks is not yet possible due to the regulations. But at our current new building in Hechingen we could soon very well use such a printer for the many areas of paving stones ". Johannes Lörcher assumes that such non-industrial applications will continue to grow strongly with the further development of the Cobots.
One cubic meter of concrete with free geometry
The Printstones X1 is an early prototype of a mobile construction site 3D printer. With it concrete elements can be printed up to a size of about 1 m3 size. The robot can be used both outside and inside. It eliminates conventional shells by precisely placing and solidifying defined volumes of material through a computer-controlled positioning process in successive layers.
The 3D printing process consists of two general steps: 3D modeling and component printing. During path generation, various methods for generating robot trajectories are implemented. In general, each layer consists of an outer contour and a filling pattern, which can be implemented as honeycomb structures or space-filling curves. The material preparation runs fully automatically via an upstream mini concrete plant. The recipe can be varied during the printing process, for example to print heavily loaded zones with higher-strength material. With this technology, components from batch size 1 can be printed in variable form.
Tool changer with key role
"Gimatic recognized the potential of printstones at an early stage and supported us with a suitable offer," says the founder. At the moment, the X1 Printstones has, in addition to the 3D print nozzle, another tool for measuring the substrate on which printing takes place. The tool changer is therefore an important part of the system and necessary for the fully automatic change between the tools.
"This application shows once again how practical it is to have a contact person on site," recalls Johannes Lörcher. "Our technical consultant Lars Janser from our branch in Graz visited the start-up in Vienna after a first contact on the part of Printstones, advised and convinced the young entrepreneurs. Our tool changer made it easy for him: the main arguments were that he is very compact and offers super-easy control. "
Characteristics of the tool changer
The EQC75 all-electric tool changer is suitable for changing applications with payloads of up to 10 kg. Mainly it is used in handling and linear robots for the industry, which work mechatronically and do without pneumatic. With its compact dimensions of 75 x 145 x 60 mm, it only weighs 1,1 kg. In the industry, for example, it fits into the tight installation spaces of many small robots in the weight class up to 5 kg. The EQC75 is controlled by the proven 24 VI / O circuit. Programming or additional control is not necessary. Its maximum torque is 150 Nm, the maximum traction 2000 N and the maximum payload 10 kg.
For users who do not want to change completely, they can easily switch between electrical and pneumatic, because the exchange system has four air connections. It was also equipped with integrated sensors for position inquiry. The signal is output via the main cable. By means of the 24-poles and the 8-pole cable the signals of the sensors and the power supply can be transmitted. Thanks to an associated, compatible adapter that is certified to ISO 9409-1, third-party products can also be connected. A subsequent conversion is easily possible.
3D printing reduces CO2emissions
"Concrete is after water the most used material by humans, but at a high price. Cement production accounts for about eight percent of global CO2 output, "Dr. Hengl to consider. The proportion of CO2 emissions from aviation is comparatively low here at 2,6 percent. "Therefore, our goal should be to reduce cement consumption wherever possible. Concrete 3D printing offers the possibility of eliminating weakly loaded zones of a component in order to save material. "
The system is designed as a multi-tool device. The concrete 3D pressure nozzle is therefore one of many possible tools. Further tools are to be developed in joint development projects with future users and customers.
"We are primarily involved in research and development and try to involve future customers as much as possible. We work exclusively with local partners such as architectural firms, industrial designers, builders and contractors. For the latter group, we still have to do some pioneering work, because the construction industry, which accounts for around seven percent of the global market, invests much less in research and development than the average in other sectors, "says Herwig Hengl.
Vision and possibilities
"Our vision, or rather, I should say mission, is the automation and optimization of construction processes. We want to reduce monotonous activities on the construction site with our technology and relieve construction workers. A good example is the laying of paving stones. Nobody enjoys laying stones on their knees in stooped posture eight hours a day. With the mobile 3D printer, these stones can be printed directly on the upper support layer of the road construction - a laying is then no longer necessary, "shows Herwig Hengl one of the possibilities.
Currently, Printstones is working as an executing company on pilot projects in the construction sector. Within five years, the start-up wants to make the transition to a system provider. The provision of hardware, software and especially building materials is the future goal.
In the future, the Viennese also see an opportunity for Gimatic grapples to be used in their construction site robots. For example, you can imagine using them for inserting reinforcement elements or other installation components. At Gimatic, the application joins a range of other exciting applications. And so in the future, in addition to picking strawberries or collecting snails in the agricultural industry as a contrast program, concrete parts will be gripped safely, reliably and efficiently.