2. Computer Aided design¶
Model (raster, vector, 2D, 3D, render, animate, simulate, …) a possible final project, compress your images and videos, and post it on your class page
What’s computer aided design (CAD)?¶
Computer-aided design is the use of computers to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing.
Types of computer-aided design software¶
There’s 2D and 3D CAD software
2D¶
- Rasters (pixels). Photoshop e.g.
- Vector (lines) Illustaror e.g.
3D CAD (main types)¶
Solid modeling (FreeCAD, Sketchup, Solidworks, Fusion 360, e.g.)
works with three-dimensional shapes. The shapes may vary, but they act together like building blocks. Some of these blocks add material while others subtract, depending on the input. Some programs can use modifiers, working with the solids as if you were physically milling it in a workshop. Solid modeling is fairly straightforward both for users and in terms of computer power.
ADVANTAGES
- Tools are easy to understand and work with; the user doesn’t require extensive training.
- Computational requirements are lower since the computer isn’t working with thousands of triangles.
- The final pieces are always mathematically correct in the sense that the model is possible in the real world.
DISADVANTAGE
- High realism in the representation of organic shapes is almost impossible to achieve.
Wireframe modeling (Blender, Maya, e.g.)
can help in cases where the surface is complex and curved. Eventually, you’ll find that the basic building blocks of solid modeling are too obtuse for some applications, and wireframe modeling provides the finesse for more complex forms. However, as complexity rises, some drawbacks emerge.
ADVANTAGE
- It’s possible to achieve more complex surfaces and curves compared to solid modeling.
DISADVANTAGES
- Users require more training.
- High resolution will require millions of polygons and computational needs will be higher.
Surface modeling (Solidworks, FreeCad, Inventor, e.g.)
For this type of modeling no program is dedicated uniquely to this technique, this is just another tool in their box. Surface modeling is the next step up in complexity. Highly professional applications demand smooth surfaces and seamless integration, and this can be handled by more advanced programs that require more work and computing power. However, here you can achieve shapes that would be nearly unattainable with the other two methods.
ADVANTAGE
- It’s possible to produce complex surfaces. This is convenient where appearance is important, such as in the automotive industry, or where fluids are involved, such as in aircraft or thermodynamics.
DISADVANTAGES
- This technique is more complex and requires more advanced programs.
- More advanced programs will demand far more training and experience from the designer.
What do I want?¶
Before I’ll try new 2d/3d software out I want to find out the general basics of these softwares. What types are out there? And how will I choose one that fits my desires? I studied Product Design and did some simple designing the last view years. During my studies I was using Solidworks. But Solidworks is so expensive (and only runs on Windows) that I wasn’t able to use it. So I tried out sketchup for some basic architectual and technical drawings. But I’m not happy with Sketchup, the layout option in awful and I don’t like the program for modeling 3d prints. Besides that, it’s not free… Well there’s a free browser version but it lacks on multiple features that an average hobby designer/engineer needs.
Before choosing a software I should know what I want from it. The following points are important for me.
- 3d printing
- Rendering
- Animating
- I want it free
- Flexible (importing/exporting files so I can work with multiple programs)
Taking the above points in consideration I made a selection of programs that I would like to learn in this Fab academy.
Types of software I’ll try out¶
••Photoshop**
Fusion 360 has a free version for hobbyists. You can only work on 10 working files, so that’ll probably be a pain in the ass. But since we use it at work, the positive feedback from users and the possibilities I want to give it a try.
FreeCAD is free and open source. This means I can use this program anywhere and anytime I want. I hope this free software will surprise me with its features.
Blender is an open source 3d animating program. With blender the sky is the limit. It has a steep learning curve, but you can do heaps of things with it. Since I’ve an interest in robotics (moving things) I would like to give this software a shot so I’ll be able to simulate how things should move. I would also like to find my way in the render posibilities.
Audacity is a free and open-source digital audio editor and recording application software. I’ve used this one for a minor project. This could come in handy upcoming weeks.
OBS studio is a free, open-source, and cross-platform screencasting and streaming app. Good for documentation.
Twinmotion (unreal engine) is a faitly easy render program that I’ve been using for architactural purposes. I might come in handy since I kind of know my way around of it.
Photoshop¶
I forgot to work with a 2d modeling software. So I decided to make the machineweek poster in Photoshop. You can go to our group page to see the beautifull result.
OpenSCAD¶
I didn’t planned to use openSCAD because I think the learning curve is way to steep for me since I don’t have any coding experience. I do have experience with 3d softwares that have a graphical interface. But Bas, who’s a previous student at fab acadamy came around and explained a bit of the program so I decided to download it and give it a try.
What’s openSCAD?
Open source parametric design tool free to use cross-platform converts textual instructions into 3D shapes No GUI
Tried the following tutorial out: openSCAD tutorial. I actually liked working with it. I didn’t expected that. But while working longer with it, it feels like a bit of wasting time since I already know this tutorial is probably the only time I’ll spend on it. Also I have my doubts when I have to make complex models with the software.
Experience
- Actually pretty cool. Because you really learn to understand the backend of the software.
- Got a lot of errors since i’m not a very accurate person. But it’s good training since I’ll probably have to write more code.
- Feels weird that I don’t use GUI options.
- If you think from a coding perspective it’s really interesting. So for me it’s not. haha.
Rhino¶
Shit, again. I didn’t planned to download Rhino but since Ashli is a big fan and took some time to explain a bit about the program I decided to spend max an hour on it to see how I’ll feel about it.
What’s Rhino?
- Big chance you’ll get to work with it if you’re an Artist, designer, architect.
- Rhino says engineers use this program too. But I think other softwares are more suitable.
- Works with Grasshopper. Grasshopper is great to automate routines. It is a tool for algorithmic modeling, specifically used for designing and editing complex shapes through certain parameters. Grasshopper
- Permanent license - full version €995. And updating cost money, but I don’t think it’s often necessary.
Trying out Rhino kind of confused me cause there are so many features that are impressive.
it’s also pretty command based. That’s new for me but I kind of like communicating with Rhino in this way. I’m more aware of what I’m doing.
Surface design tool. Defenitily goof for designers / artists for concept modeling.
Really good tutorial if you already a know a bit of 3d modeling. Rhino tutorial
I actually really like the software! It surprised me with the variety. I need to skip this one fast because number one rule for me is FREE or CHEAP. I want to be independent.
FreeCAD¶
FreeCAD offers tools to produce, export and edit solid, full-precision models, export them for 3D printing or CNC machining, create 2D drawings and views of your models, perform analyses such as Finite Element Analyses, or export model data such as quantities or bills of materials.
- Same features as solidworks.
- It does surfacing
- Mesh
- It even has physic analysis
- technical drawings
- Open source so also for commercial use
1: creating a model using body
I can’t edit it if i’ll press the cilinder
You want to achieve fully constraint
Start with a body if it’s a simple shape. Start with a sketch when it’s complex.
I thought that it would take me less time to understand it. I don’t have the patience to watch tutorials from 30 minuten per theme. But from my experience it costs a lot of time to learn a program.
(good beginners tutorial freeCAD](https://www.youtube.com/watch?v=QzRjzBw3ymE&ab_channel=Adventuresincreation)
If you’re not totally new to 3d modeling software I would suggest that you watch tutorials of models that you think you could make.
This tutorial is good for my basic design of my discs of my final project: discs tutorial
Modeling my final project¶
1:
The first thing you should is analyse your model. Make a sketch (paper & pen) and think about how you want to model your project. Since freeCAD is a parametric design software you should know your dimensions. Make a plan of the tools/features you want to use. And think of a logic chronolical way to build your project.
2:
You’ve sketched your model. You thought of a plan. Now it’s time to start modeling. Since FreeCAD is new to me I thought of similar projects to mine. Vertebrae- or boat designs are quite similar. I searched from some tutorials and got started.
3:
First we’ll make one disc. I’ll try to constrain the holes in my disc with an offset from the outer line so I when I change the dimension of the dics my holes will keep the same dimensions and distance from the outer line.
This is the wrong constraint
Constraining is a pain in the ass. Since I want to constrain my hole with the outside line and not with the centerpoint. Cause when I scale my disc, the diameter of the holes won’t change, but the distance between the hole and the outside line will stay the same. I hope. It should be easy but constraining takes a while to get it.
I want to use a circular pattern now, which is called polar pattern. I find it weird that in all the tutorials the first make a solid and cut the holes from it. Why not make a sketch and extrude it with holes it in? I can’t though because the polar pattern is only used in the part workbench….
Holy shit. $%@#$@!#%!#%!#%!#% freecad! I want to make a part out of my sketcht and it gives shit instead of extruding it. Why do the make simple things difficult.
If you started a sketch without opening a file with a body it won’t work.
Extruded the sketch. Made new lines.
After getting mad a couple of times I found a tutorial that explained why my plan didnt work out. I needed a couple commands. reference constraint, external geomatry and construction geomatery made it al happen!
Good tutorial for cutting holes and polar tool
By using the correct features in a chronologic order I can change my dimensions of the outer circle and my outer holes will move while keeping the same offset distance and diameter!
4: Pattern a body
When I tried to linear copy the body FC crashed. You can’t linear pattern a Body
If you go to draft in your workbench. Select array.
I can’t change the body’s indevidually now….. I think I’ll just copy the body’s… I copied the body replaced it on the Z axes and changed the diameter. It works.
It works but it takes a lot of time! Alternative; I can use array -> downgrade -> I’ll get individual solids but the history is gone so I can’t change the sketch but I could add fillets chamfers etc.
I found an other way which is still not ideal yet. But I need to keep going.. I stay in the part design workbench and use clone. Right click on the body and transform. I can’t find where to adjust the right distance. I need to do this with folllowing (tutorial)[https://www.youtube.com/watch?v=QB2g71oZOok&ab_channel=MangoJellySolutions]
ohhhhhhhhh, I cloned them all. But clones have alzeimer. shit, i didnt pay attention.
Adjusting them was taking me to long. And I know there’s a faster way for it. I cheated a bit now but I need to continiue.
When I want to create another circular pad that goes through my holes i get an error.
Not happy with the result of my model but I need to go the next step
Blender¶
I exported the model as an STL file in FC and imported it into blender. I checked the lenght of the cube. It’s 100 times to big. Export freeCAD file to Blender
I’ll import it again and set the scale to 0,01 Its a hassle to edit the STL file from freeCAD in blender, so I’ll give the modeling in blender a shot.
Since my final project that I made in FreeCAD was a pain in the ass to edit, I’ll try to import a simple model from FC and copy and model some new stuff in blender and try to edit it in a soft hose.
Want to add single vert to my model. Could’t find it. Needed to go to preferences.
To make a single vert for a flexible hose I used these two tutorials
Using multiple tutorials won’t work with my level of expertise…. haha
I’ll found one that will help me correctly. I’ll follow this tutorial so I won’t make faults. If can do this turorial I can make my own easier.
I’ve created dynamic rope simulation.
Video 1 video 2
Fusion 360¶
I didn’t had a lot of time left before the global meeting started but I definately wanted to give Fusion a shot to know if I wanted to give freeCAD a real shot. I was working 30 minutes without tutorials and I made the following model. The software is way easier!!
Tips and questions¶
- Find a tutorial that matches your skill level.
- I want to talk about documenting. What should I write down and what not?
- Not convinced by FreeCAD. Lots of errors. Not easy in use. Graphics are poor. But it's free and the have all the import features.
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Assignment¶
Model (raster, vector, 2D, 3D, render, animate, simulate, …) a possible final project, compress your images and videos, and post a description with your design files on your class page
Freecad¶
