Creating a Robotic Arm Gripper using Generative Design

CENGIZ KURTOGLU: Hi, and welcome to the Creating a Robotic Arm Gripper Using Generative Design session at Autodesk University 2021. My name is Cengiz Kurtoglu. I'm a mechanical engineer in France, upper Normandy, but originally from Turkey.

I'm working with Autodesk for six years to provide Fusion 360 lectures and workshops to university students and academic staff, from basic to advanced level. I started as a student expert to my Autodesk journey. I have three years experience at Acibadem Incubation Center as a design coordinator.

I've supported different startups which are specialized in the field of medical technologies. We have produced many prototypes and products using generally additive manufacturing technologies. I'm currently working on a research project in the soft robotics field.

Also, I'm the founder of the designwagoon.com I'm creating content about 3D designing, concept 3D printing objects, and 3D designing courses. You can take a look at designwagoon.com.

Generative design in Fusion 360. Generative design mimics nature's evolutionary approach to design. After you input design goals into generative design software, you will have different parameters which you can assign as materials, manufacturing methods, or cost constraints.

Fusion 360 explores all possible permutations of solution for your design problem. Unlike topology optimization, generative design can provide you with dozens of new design outcomes without any initial shape. Generative design is all about exploring more possibles and coming up with a better design that's more innovative.

The part is very organic looking and can only be manufactured on a 3D printer. But times have changed. You now have the ability to manufacture parts created from generative design using traditional process like two or three axis tool parts, or if you are cutting from a plate, you can think of three to five-axis milling. Generative design has become a co-creator of 3D modeling, along with the engineer by including the engineering requirements like material manufacturing process, loading conditions.

Well, in this session, I would like to show you how you can create a robotic arm gripper holder using generative design model. We'll talk about step-by-step how to design a concept part according to your needs. You can see some examples of generative design outcomes. On the left, in below part, is our outcome weave of generatively designed robotic gripper.

Let's take a look at our headlines before we switch the Fusion 360. Workflow for generative design. In the first step, we need a project and a problem. Generally, you have the computer-aided design project in your 3D software. But if you haven't, you can create in Fusion 360 design workspace as solid formal link or surface.

In this section, we will create our related bodies in the CAD modeling workspace. You can follow the video instructions or you can get the necessary information from the handout file. After you determined related bodies for generative design study, you have to define preserved bodies and obstacle bodies.

In generative design study, we should assign preserved geometry that it allows us to add loads and constraints. Preserved regions are areas where we want to maintain the size and the shape that we define in the model. Obstacle geometry is not obligatory to add in generative design study. But in many cases, it will help when you need to assign empty spaces where the material placed during degeneration of outcomes, so obstacles are areas in the design where we don't want the generative design to allow materials to enter.

After you complete the assignation of parameters, you will be ready to generate. Fusion 360 is a 3D design and collaboration tool that allows users to build and evaluate 3D CAD models and drawings. This is the tool we will use to build, document, and evaluate the models that we will use for generative design.

So, generative design model is a tool that is available in Fusion 360. The setup and configuration for generative design is completed inside the local software. We'll use the generative design model to create a robotic arm gripper holder in our project. The files and setup are uploaded and the analysis is completed in a server where you can review the results and then download the finished result.

Fusion 360 offers us a detailed explore page, which contains many outcomes. You can easily change the object range from outcome filters, and you will see only outcome thumbnails that you need for your necessary. So the important thing is to find the best solution for our design problem.

Which material will be the proper for you? What is your mass target for the parts? Is it a convenient design to manufacture it, and et cetera.

After you decide the optimum outcome iteration design, you can export 3D design part, which you can add it in the design workspace. In this session, we will create a generatively designed robotic arm gripper holder using these main steps. Let's take a look.

Well, the first part will be the modeling. As you saw on the previous slide page, you should open a CAD project, or you can design related bodies in Fusion 360. We will use the CAD modeling solid modeling workspace to design the necessary parts that we need for generative design.

The second part will be the preparation. We will modify the bodies because generative design study needs to preserve bodies, obstacle bodies, or starting shape to run the algorithm. Also, there will be hints for your average steps in Fusion 360. When you slide your mouse to the icon to learn from, the modified process is the [INAUDIBLE]. That You can modify in your related bodies in the design model or you can use the generative design added model workspace.

I think the third part will be the most interesting part for you, generative design. There are several steps to assign what we want from Fusion 360. You can easily assign constraints and loads to your parts, as you know from other simulation studies. At the same time, you can select different manufacturing methods or materials for the same study. I hope it will be very interesting for you to get inside details of Fusion 360 generative design.

For the last step, results, outcomes. We will obtain lots of outcomes from generative design study. The most important thing is that, how are we going to make a comparison between the outcomes and how to determine the best design for our needs? It will be the questions in this and other generative design projects.

Now, it's time to start our project in Fusion 360. Modeling exercise. Well, we can start with the Create Sketch tool. And I'll choose the exact plane. You can start with select the rectangle tool or you can just press the R key in the keyboard.

Then, I'll choose the center rectangle on the sketch palette. And we can enter the values using tab button to switch between the dimensions and hit the Enter button. Then, I'll choose the line, just pressing L key on the keyboard. Then, we'll draw the two lines.

After that, you can use the equal tool on the constraints to equalize the two lines. Then, I'll pick the Smart Dimensions tool and you can select the two points of the lines. Approximately 38 millimeters will be proper.

And then, I'll create the region of the servo motor using rectangle tool, just pressing R key on the keyboard. Then, you can enter the dimensions that you want for your own servo motor or concept dimensions. Then, we'll create four circles for the screens of the servo motor and holders.

Then, I'll select all circles using Shift button on the keyboard. And then, I'll click the right button on the mouse and select the equal on constraints. Then, you can use the Smart Dimensions tools to define the all dimensions in this sketch.

After you complete the drawing on the sketch, you can press the E key to use the Extrude tool. And I'll click the Home button on the View cube. Then, you can enter the 4 millimeters for the profile extrusion.

To use the Filler tool, you can press the F button on the keyboard. Then, I'll select the four edges for the servo motors. And 1.14 for the fill tool.

Also, we'll use the fill tool again. This time, 10 millimeter will be proper for our design. And the other side of the parts, we will use the fill it tool again. And 13 millimeters will be OK for our part.

After that, I'll create the sketch of the bottom of the face, the parts, then I'll draw a line using L key on the keyboard. And after define the dimension of the line, you can use the Extrude tool, just pressing E button on the keyboard. Then, you can enter the 34 millimeter for the part.

In the last steps, we'll use the rip tool to reinforce the strength of the parts. I'll select the Create Sketch. Then, you can draw a line between the two side of the parts.

Then, I'll use the Smart Dimensions to define the distance between two points. And then, you can also define the angles between two lines. After that, I'll select the Rip tool. You can press the Flip Direction and then select the one side. And we can enter the 5 millimeters for the thickness of the rip. Then, hit the OK button.

To create another rip area on the other side, you can use the mirror tool, just pressing as button to search the all tools on the Fusion 360. After you open the mirror tool, you can select the different types for mirror. Now, I'm using features. You have to select the last tool that you create as rip.

And then, we have to use the mirror plane. For example, you can select the xy-plane and then hit OK button to create another rip to the other side of the part. And then, for the last part, we have to create some holes of the backside of part.

After you create sketch, you can select the center slot, and then you can define the dimensions of the slot. After you finished the define the dimensions, we can use the mirror tool on the sketch, also. To use the mirror tool, you have to create a mirror line. And we can change the line as construction line, just pressing X button on the keyboard.

And then, I'll use the sketch shortcuts, just pressing S button. Then, in the mirror tool, you can select the objects and mirror line. Just hit the OK button. And then, we can use the Extrude tool to use the cut operation.

After you selected two profiles, you can easily cut the parts. And after that, it did OK button. Well, the part is ready. And we have to modify these parts to prepare generative design process. There's two options for that.

You can use the design model to modify the body, for example, using Split Body tool. Or you can enter the generative design model and easily use the added model on the generative design model. If you use this option, the parts will remain always the same.

But if you modify the parts in the design model, it could be hard to organize for other models. Well, in this session, we're going to use the Modify tool and the generative design model. You can follow the next steps for that. Also, you can save the projects using Save icon or Control S button on the keyboard. Then, you can easily select the type of projects, and enter the name of the design, then press the Save icon easily.

New generative design study. Well, you can get information in help quick setup on the top right on Fusion 360 near your profile picture. There are detailed information of all process for generative design. Well, for the first step, you have to answer the generative design model on Fusion 360.

You can use the model parts on the toolbar or just click the right button on your mouse, then choose the workspaces generative design. After you enter generative design workspace, you can use the guides to get information about your steps for generative design process. Well, normally in generative design, it opens structural study one as default.

You don't need to use the new generative design study on the toolbar. Well, to prepare the preserved body, obstacle body starting shape, we can use the Add Model in generative design toolbar. The added modal toolbar is also available on the simulation workspace.

Well, it's generally handy to use for just preparation, the parts for simulations and generative design process. Well, I'll use the Create sketch on the top face of the part. Then, I'll use the offset tool. The shortcut is O.

Well, we can select the first circle and 1 millimeter for offset position is proper for us. To repeat the last step that you already use, you can press the right button on the mouse, then repeat the last step for offset. We'll repeat it two times again for the other circles, and then we can enter minus 3 millimeter for inside rectangle for servo motor.

These regions will be demonstrated are preserve regions. It's so important to create these thickness using offset tool, because these regions are necessary to hold the servo motor you can think this way to modify your parts to determine your preserved regions on your project. And then, I'll use the Split Body tool.

First of all, we can select the part to split. And then, as splitting tools, I'll select the four circles. Then, hit the OK button. Well, we have five different parts. After that, I'll change the visibility of sketch.

Then, we can select the Split Body tool again. Now, we can select the [? body 5 ?] for the body splits, then a splitting tool, the rectangle drawing, and hit the OK button to finish the process. For the backside, we can use the same steps. But now, I'll use the project tool to define the slot lines.

You can select the lines that necessary for us and then hit the OK button. After that, I'll use the Offset tool, using [? Alt ?] key on the keyboard. Then, 2 millimeter will be quite enough for offset position. Then, repeat again for other slot. After that, we'll use the split body tool again for two of them. Then, it will be ready for preserved regions on the generative design process.

Assignation of preserve geometries. In generative design study, it shall be assigned preserve geometries that it allows adding loads and constraints. Preserve geometries also will appear in the final shape of the design. Well, first of all, you can use the Preserve Geometry icon on Design Space on the toolbar, or you can click the Add button on the preserve geometry.

After that, you can select the any bodies that you want to define as preserve geometry. In our case, we have to select four cylindrical shapes as preserve geometry because we need to assign some loads on acting of these services. Also, you can select the rectangular body to hold the servo motor. The shape will also get some force to hold the servo motor or some weights acting on the robotic arm gripper.

On the back side, we have to select two shapes that we created on the added model because the preserve bodies is necessary to assign forces, and also for the constraints. These regions will be defined for constraints inside of the faces. Well, after you completed preserve bodies, hit the OK button. And then you can click the right button on your mass to the seven bodies, and hit the Isolate just to see the preserve geometries on our project.

Well, I noticed the backside of the parts could be more smaller. Well, we can use the Added Model tool again. I'll use the Visibility tool to see all bodies on the project. Then you can use the Press Pool tool just pressing the Q button on the keyboard. Then select the face.

Well, we can change the position as distance 4 minus 5 millimeter. Then hit the OK button. It perfectly changed. Then after you finish the process, you can hit the Finish Added Model. And now the preserve regions are changed after we used the added model on the whole process.

Assignation of obstacle geometries. It's not obligatory to add obstacle geometry in generative design study. But, in many cases, it will help you when you need to assign empty spaces where the material placed during the generation of outcomes. Well, to define the obstacle geometry, we need to create some geometries in added model.

After you enter the Added Model workspace, you can easily create a box. First of all, I'll use the top face of the parts. Then you can create a rectangle of the box. Well, we need to select New Body as operation, and then hit the OK. Well, I would like to use the offset face for the top of the box. You can use the Q on keyboard. And 3 millimeter will be OK. And hit the OK.

Well, now we can't see any parts of our design. There's a handy tool to change the opacity of the parts. You can right click on Body9, then choose the opacity control as 50%. Then you can easily see the inside of the box.

Well, now we can use the combine tool to cut the all interference parts as box, and the other parts. Well, I'll use the target body as box Body9. Then as tool bodies, the rest of the old bodies, you can select the cut operation. Then, this is the important thing, to hit the checkmark for key tools because if you don't, the all tool bodies will be erased.

After you've finished the process, you can hit the Finish Added Model. Normally, there is another handy tool as obstacle offset. But, in our case, the shape is very interesting and the obstacle offset is not available for our shape, but you can use on your projects.

Well, to solve our problem, I'm reopening Added Model and I'm press and holding left button on my mouse, then you can see the depth faces in order. Well, I'm selecting the face that I want to choose. And then you can use the offset face just pressing Q button on your keyboard. Then I'm changing the position I will use for the other faces also to offset the faces. After you complete the process, you can hit the Finish Added Model, and your obstacle body is ready for generative design.

Well, I generally use these techniques to cover the all parts that I don't want to see on the final shape because the obstacle geometries will be never exist in the final shape. Also, there is another hint for you. If you maximize your obstacle body faces regions, that will be quite nice for generative design algorithms you probably see on your own projects.

Starting shape. In generative design study, starting shape is an optional tool. You can assign it as initial shape. And if you already use the topology optimization, it will be quite understandable for the next steps on generative design study.

Well, to use the starting shape, we can open Design Space and starting shape. I'm selecting the part, and I'll hit the OK. The starting shape is generally demonstrating as yellow on the Fusion 360. Well, you can use the isolate and unisolate them. Well, we will use two different generative design study. One of them with starting shape, and the other without starting shape. And we can easily compare the results, outcomes with and without starting shape.

Structural constraints. Well, if you already use any type of simulation analysis tool on Fusion 360 or other softwares, I'm sure you know the structural constraints are very important for the simulations. Well, we can see these same road, same force acting on the parts, but the position of structural constraints are different. Left side has more displacement, but the right side is quite different answering to the force acting on the same face.

Well, in generative design, you can select the design conditions to open the structural constraints, or you can easily press the C key on the keyboard. Well, we can start to select faces on our backside of the design. If you select the inside of the faces, you can press and hold the left key in a couple second, and then easily select the face that you want. After you complete the selecting faces, you can choose the type of your structural constraints.

Well, there are three types of structural constraints-- fixed, pin, frictions. We'll use the fixed type of structural constraint and acting on a three axis on the projects. You can see the axis on the view cube as XYZ. Well, hit the OK button to confirm that.

Structural loads. In the generative design study, structural constraints restricts or limit the movement of the model. Structural loads creates forces acting on the body. In generally, it shall be preserve body because we can only select the face's edge vertices on the preserve regions.

Well, in this session, we can consider that the generative design study should create a conceptual robotic arm gripper under estimated condition. As you can see in the left side of the figure, force is acting on the top face of the body. Well, also, the backside of the two holes are demonstrated as structural constraints.

After that, if you're on that static stress analysis, we can see the displacement. Report of the static stress analysis. Well, as you can see, the red regions are maximum displacement because of the acting of forces. Well, we can think about to combine these results with generative design.

Well, as you can see, there's a frame, and four side of the frames are structural constraints. And in the center of the circular part, the force acting. Well, what do you think about the generative design creates the meshes on which side of the gap side? Well, it looks like a generative design creates center regions only. The corner sides is not necessary.

Well, maybe we can consider the static stress analysis of the same parts. Well, as you can see, the results of static stress analysis in the same frame, the maximum displacement is acting on the, in generally, center. The corners is not absolutely necessary because of the distance to the force acting regions.

Well, in another example, the same frame, but the force acting on the upper side to the center. Well, what do you think about the results of generative design? As you can see, the most parts of the meshes that's created by generative design are center, upper, and lower regions. It's quite different results, actually. But it's not surprising for us because if we solve the static stress analysis for the same problem, as you can see, the results is look like elliptic. It's quite different because force magnitude could be same, but the direction is different. And the results of the static stress analysis and the outcome of the generative design should be different.

You can think about these examples, and we can start our assignment of structural loads. Well, first of all, you can select the design condition and structural loads, the L key is the shortcut on the keyboard. Well, we can start with the inside faces of four screw center tubes.

Well, you can use the manipulator to change the direction as a rotating tool, but you can also use the direction type as normal or vector type. Well, to find the axis on the Fusion 360, you can always see the view cube. Well, I would like to enter the 40 Newton to the Y direction. But from top to bottom side, well, we can use the minus to change the direction.

Well, you can always change the units in the structure loads. And after I assign the loads, you can hit the OK button. After that, I would like to create new load case, but using clone load case because every time, you need to create need constraints. But using clone load case, it's not necessary. And if you switch the load case2, you can click the small Activate button. And then I'm selecting Edit on Force2 and deselecting faces.

Now you can select the inside of the servo motor holder parts, the faces, eight faces, or you can easily select the top faces to determine the force. Well, I'm using same force acting on the face. And then hit OK.

Well, in generative design to use the different load cases, it's quite important to obtain different generative design outcomes. For that reason, we created two different load case in this project. And also, there is another tool in the design conditions load case attributes. Well, you can easily edit double-clicking on force, or gravity, or constraints acting on our parts.

Objectives and limits. In this session, we would like to reach the lightest solution for concept robotic arm gripper. For this aim, we can easily choose the Minimize Mass as objectives. In general, it's proper to enter a value for 2 for safety factor on limits. But if you want to reach more detailed outcomes, I'm proposing you to use the mass target tool. Well, we will use in our projects and we will answer the value for target mass as in the unit of kilogram.

Well, after you select the objectives and limits, as you can see, we can select the Maximize Stiffness, but we should enter the mass target. For that, we have to know our material mass properties. Well, we can switch the design model, and you can right click the body physical material. Well, firstly, I will use the aluminum 61 to see the mass in general.

After you drag and drop the material on the part, you can right click the body and choose the properties. Well, the mass for aluminum is 63.5 grams. You can also change the materials, maybe ABS plastic, just to see the mass for the same parts. Well, as you can see, the mass is dramatically dropped to 25 grams approximately.

Well, let's switch back the generative design model. And then I'm answering to the safety factor 1, and to the mass target 0.015 kilogram. But for the aluminum, it's quite proper target mass. But for the ABS plastic, you can change the value smaller for your own projects.

Manufacturing and materials. Well, the important thing in generative design is we can select the manufacturing method. For example, additive manufacturing, or milling, 2-axis cutting, die casting, or unrestricted. That is, generative design isn't taking into account the manufacturing methods.

Well, in the detail of the properties, we can choose the orientations for manufacturing techniques. And, for example, for additive manufacturing, we can select the overhang angle or minimum thickness. That is quite important for manufacturing details. We can take a look what's the overhang angle. There are three different types of overhang angle example in the figure.

Well, the left side is 30 degree for overhang angle. If you use the additive manufacturing method, you have to use, in some cases, supporting materials for your 3D printed parts. Well, maybe 30 degree or 45 degree overhang angle, it's not hard to manufacture for 3D printers. But 60 degree could be hard to manufacture for 3D printers. Maybe it could be 90 degree.

Well, in general, it should be use the supporting materials for these regions. Well, if you take into account the overhang angle, you can define your degrees as manufacturing method properties on generative design. Well, we can start to define our properties for manufacturing methods in our project.

Well, we can start with additive manufacturing methods just selecting the checkmark to the additive. Well, I would like to obtain six different orientations for additive manufacturing methods. You can easily press the checkmark, include all six directions. That could be six different outcomes on Explore page of generative design. You can think about the change the position of our parts to start the manufacture on the 3D printer. Well, for the overhang angle, you can use the 35 degree and 1 millimeter for minimum thickness.

But, also, we can select the milling manufacturing technique. For the default, it's using three axis. We can, again, select the check mark, include all six direction. And I'm entering 2 millimeter for minimum total diameter, 20mm for total shoulder length, and 20 millimeter for head diameter. If you wait in a couple seconds in the tab, you can see some information and pictures for the related parameters.

Well, you can also add new configuration as 5-axis to our milling manufacturing techniques using the same dimensions for parameters. After that, also, I'm adding unrestricted manufacturing technique. Well, it's not a manufacturing technique, it's just for the generative design things, there's no restriction for manufacturing techniques, actually.

After that, you can also checkmark on cost estimation, then hit the OK button. Well, it will select two different materials as plastic and metal, but feel free to choose different materials for your cases. Well, I'm choosing the materials. And firstly, you can change the Fusion 360 material library. And I'm selecting aluminum 6061. And also, you can change the methods for your related materials.

Then I'm adding the plastic as ABS plastic in our project. After you confirm your materials, you can see the manufacturing and the methods for manufacturing. As you can see, it's all the materials are assigned, fir the related manufacturing techniques.

Well, ready to generate. We can quickly select the Pre-Check tool to check everything before they use generate tool for generative design. As you can see, there is a warning for some bodies are hidden, but it's not quite important. After you change the visibility of your bodies, the project tool should be changed as the study set up has all the information required. After all confirmed for your project, you can hit the Generate One Study.

Exploring generative design outcomes. Well, in the interface of Explore page, you can see the outcomes of your projects. Well, in the left side, there is outcome filters that you can easily use. Maybe if you'd like to see just without starting shape outcomes, you can select the Isolate for structural study one. Then, as you can see, these outcomes for without starting shape.

Well, on the top side, there are recommended outcomes from Fusion 360. If you press the Compare, you can easily compare four of them. Also, there is another range for objectives. Maybe you can change the mass, and you easily compare of them.

If you want to see more details on this thumbnail page, you can change the properties view. As you can see, there are lots of information about outcomes, such as material, orientation, mass, factor of safety limit, and et cetera. Also, another view for table view. You can change the recommendation and could we see the materials, manufacturing methods, and et cetera.

Well, if you know which materials that you want to use, you can easily isolate of them and comparing visually. Maybe we can take a look of outcome 10. After you double click, you can easily to see the design. Well, generative design creates most of iterations. If you come back to first iteration, it looks quite heavy to use and manufacture of them. But the iterations are always run for your objective limits, manufacturing techniques, materials, all your wishes to reach the optimum design for you.

Also, you can see the stress view acting on the parts. It looks ideal for the stress reference. And also, there is design preview and transparent view for detailed visually looking.

Details of the scatter plot view. We could see all outcomes and the one table as scatterplot view. After you reset all filters, you can see the all outcomes in one table. Well, if you use the left click on your mouse, you can zoom on the outcomes.

Well, as you can see, there are three colors for the material symbols. You can easily change the as manufacturing methods, or visual similarity, and et cetera. Well, we can change as manufacturing methods. In the x-axis, we can see the mass as kilogram, and y-axis, the minimum factor of safety.

Well, I'm looking for approximately 1 for the factor of safety, and I would like to choose the additive manufacturing technique. Well, if you take a look the regulation of visual demonstration of the outcomes, you can see these small timelines. If you press the Control button, you can select the iteration history of selected outcome, as you can see.

Well I'm pressing Shift button to select different outcomes to compare of them. After I select four outcomes, you can select Opens the Comparison View icon. Well, in the same way. We can compare four different outcomes. If you select one of them, you can see the detailed properties in the right side of the screen.

Well, as you can see, there are quite nice outcomes in our projects. Well, I can select the stress view acting on the outcomes. Well, I would like to choose the additive manufacturing methods. As you can see, these methods for manufacturing 3-axis milling. I'm erasing this one, and this one is unrestricted, as you can see. It shall be erased these parts.

Well, it's not so hard in Fusion 360. After you use the design from outcome we can erase these meshes using four modeling tools. But for now, I'm erasing this one. Well, after your comparison on your projects, I'm selecting this outcome for my project. After you complete your process, you can easily use the Create Design from outcome view.

Design from outcome. Well, you can easily create 3D designs from your selected outcome iteration using Create Design From Outcome. Well, at the beginning of this session, we started creating a box and some sketches. And now, that's the results of this session-- generatively designed robotic arm gripper holder.

Well, to obtain the design on the design model, I'm selecting Design From Outcome. And Fusion 360 prepare the design as a mesh. After completing the process, it will automatically open the design for me in a new tab.

Well, after you open the outcome of the generative design, you can easily edit the four model of the outcome. I will right click the formal link icon on the timeline, and click the Edit. Then I'm changing the display settings, the visual style shaded with visible edge only. And then you can select the Modify tool. And I'm selecting edges using Shift on the keyboards. Then I'm using the scale tool of the manipulator to more thicker for these parts. And then hit OK and finish form.

As you can see, it could be modify of your outcome that you selected on generative design. Well, for the last verse of this session, there are different types of works on the robotic gripper designs. As you can see, there is an example of simulation of soft robotic gripper actuator that I am working as researching subject on my project. Well, this simulation also is solved on Fusion 360 analysis tools. Well , I hope this session will contribute your work. All the best.