Robots and 3D printing

Many interesting design solutions and discoveries do not occur in a specific area, but at the boundaries of the spheres, which would seem completely unrelated. Take such a narrow physical property as the spin of a proton in the nucleus of a hydrogen atom. At first glance, it may be interesting only for theoretical physicists, but it was this property that formed the basis for MRI, a method for studying internal organs. And the Markov transition matrix, which is used to search for statistical equilibrium in different processes (a very specific thing, little known outside the world of mathematics), has unexpectedly found use in linguistics and is used to identify authors of literary works.

So we want to talk about one solution on the border of different areas of knowledge, although not as great as an MRI or the identification of authors.

The small town of Laufen is located in the heart of Germany, not far from Stuttgart. Wherever you look, vineyards stretch to the horizon. Actually, most of the inhabitants of these places are engaged in winemaking. But there was a place here and high technology.

Schunk company began as a garage for the repair of electric motors in the far 45th year. Now, almost 70 years later, this is a large company with a turnover of more than 250 million euros and more than two and a half thousand employees. Schunk - one of the leaders in the production of robotics in Europe, in particular, robotic capture devices - grippers. Imagine a conveyor line, which endless flow of some items. And the mechanical hand grabs these objects and rearranges somewhere. This hand is the gripper. Now imagine that these objects have some very complex form. For example, it's a chocolate bear like this
')


A gripper with ordinary rectangular fingers will not be able to grab such an object, because it will simply slip. Now, if the outlines of the object were cut out in the fingers ...



Such requests arose from many, and Schunk's clients regularly ask us to adapt the fingers of the grippers to the specific ones needed. Usually they send either a 3D model of the object or a drawing in general. Schunk experts spend several days at first creating the model itself, then making the necessary cuts on the contours of the fingers, and then cutting out the desired contour on the milling machine from metal blanks. It turns out long and expensive, because the valuable time of the experts is spent on the gripper, which will be produced in 1-2 copies and will not be needed by anyone except one single client.

In search of a solution, how to automate the whole process and make it fast and convenient, Schunk experts turned to Materialize. Well, Materialay, as you know, is not only one of the world leaders in the 3D printing market, but also possesses a huge knowledge base in terms of processing 3D models.

The task that was put before the working group sounded like this: to develop a solution that would not require the customer to have any special knowledge in 3D modeling, but would allow to get customized fingers for the gripper, having only a part model that the gripper should capture at the entrance. Well, do it in a few seconds, not in a day or two.

What conclusions can be made immediately with this formulation of the problem? First, it should be a browser solution, because we do not want to burden the user by downloading and installing unknown software. He only needs to have a part model. Secondly, if the user wants to see the result almost immediately, then the system must be fully automated.

The work began with the tasks of trimming and 3D-in-browser, because they were the most risky.
We didn’t have full experience of managing 3D models in the browser, but it was necessary to provide the user with a simple and convenient mechanism for orienting parts in space and relatively to the gripper.

In addition, trimming the fingers was also quite difficult, because in some places it was necessary to leave gaps so that the part could be easily removed in the open state; and in other places, on the contrary, protrusions so that the part is tightly clamped in closed fingers.

To solve the first task, we spent quite a lot of time on research, but it paid off with interest, because this part of the work was very risky and the problems there would have cost much more. As a result, we stopped at the library Three JS.

Variants of the mechanism of orientation details tried about five. The ideal was not found among them, so they settled on the one that seemed optimal.

Debugging a fingermaker (as we called the utility for pruning) also proved to be difficult, and it was very good that we were engaged in it from the very beginning.
Of course, the difficulties arose very different throughout the work, but, one way or another, they were overcome and the result was the egrip system.



So. The system itself is a browser solution. The client loads the 3D model of the part (stl or stp), selects some basic parameters and positions the part relative to the gripper, and then all the work is done by egrip. After a few seconds, the client receives the model of the gripper already with the cut out contour, and if he likes the result, he immediately places an order. The whole process takes several minutes and takes place interactively, i.e. All user actions for moving and rotating parts relative to the gripper are immediately displayed in the working window. Fingers are printed on a 3D printer and sent to the client by mail.



Everything is very simple. Of course, for such simplicity is the work of people, countless meetings, many liters of drunk coffee. But as a result, we have a system that developers are proud of, customers and customers are happy.
Yes, and the first orders are already there, if anyone is interested.

Anyone can register and work with the system independently at www.egrip.schunk.com . Unfortunately, while registering, you can specify the address only in a few countries, so the product may not be ordered, but there are no other restrictions.