Peter Fearey

Computer Aided Design

Assignment

Model (draw, render, animate, simulate, ...) a possible final project and post it on your class page (with as many tools as possible).

Ideas and Approach

Throughout the past few months I've gotten pretty good at vector graphics using CorelDraw. This has largely because that's what we were told to use with our school's Full Spectrum Laser Cutter. Therefore, for this assignment I am going to focus on trying to learn / explore:

one new 2D tools...one new vector graphics program (Inkscape)
two new 3D tools...one simple 3D tools (TinkerCAD) and one advanced tool (Rhino)

Files

Steps Taken

CorelDraw to Inkscape

My first goal is to learn Inkscape and so I am going to try to recreate my vector graphics for the control board into Inkscape (rather than CorelDraw- which is what I used in the week one diagram). This proved to be pretty simple, but I ran in to some inconsistencies that drove me nuts between the two programs. Here are some of the differences between the two....

Inkscape

CorelDraw

Clone: The clone feature looks really promising. I started designing my week 3 project and it was great using it to model the width of the material. Unfortunately, I did find it a bit problematic once I attached the cloned item to other items.

Boolean Logic: I imagine there's a way to do it in CorelDraw, but I haven't find it. The notion of using Union, Difference, etc on objects seems quite useful.

Working with Nodes: I get the sense that both programs can do all sorts of manipulations with nodes, but I saw some things that Inkscape does around aligning and distributing nodes that I couldn't find in CorelDraw (and have looked for because I've needed the functionality).

Node Placement: OK...I just discovered this and this could be my favorite so far. You can enter the coordinates for the notes. This matters because if I need a node to be .23" away from another node, I can force that. To date I haven't found a way to enter node coordinates.

Centerline Trace: CorelDraw does a wonderful job of tracing bitmap drawings. Unlike Inkscape, you can do a trace that turns a line into a hairline (rather than a curve. This is quite useful when trying to trace something you want to vector cut (e.g. the perimeter of something).

Object Manager: While Inkscape does have the concept of the XML Editor, I think CorelDraw's interface and layer functionality seems better. For example, you can specifically say whether you'd like to print a layer in Corel.

Text Formatting: Unless I was missing something, CorelDraw provides many more options for formatting text. For example, I couldn't find a way to underline my text in Inkscape.

One thing that I was quite happy about was the fact that I could easily print from Inkscape to our laser cutter (a Full Spectrum laser). I had tried this before, but it wasn't until someone on the fabacademy thread mentioned setting your line width to .01 inches that I finally figured out how to do it. Here's the most useful part of the email: "The linewidth crossover point between rastering and vector cutting is a function of the raster dpi setting. i.e. for 600 dpi it is 25.4/600 = 0.042mm ; at 1200 dpi it is 25.4/1200 = 0.021mm so 0.01mm line thickness is a safe bet as it will always vector cut no matter what dpi setting you are using on Epilog mini 40w.". Thank you to Dr. Eddie Kirkby for that information.

All in all, this was REALLY useful as it helped me to realize that Inkscape isn't that bad and that I should be promoting it (and potentially using it) at our school.

Here is what I ended up with in Inkscape. Not that different from what I had with CorelDraw, but I finally learned how to get around Inkscape.

Inkscape

TinkerCAD

I have never really modeled anything in 3D. Given that, I figured I'd start simple. So I went with TinkerCAD. And to work with that, I decided to try making the bounce-back design. There were three parts to the design...the outline, the inner "tiles" that were going to contain the target LEDs and the pressure sensors and the LED display at the top of the bounce-back.

Limitations

As I used TinkerCAD, I immediately started to run into limitations. Here were some of the ones I hit:

Workspace size: The workspace can only be 40" x 40". This presented a problem because my bounceback is likely going to be bigger than that. To get around that, I designed it as 12" and will scale it up.
Align/Distribute: Once I figured out the Align command things moved a bit more quickly. Having said that, I did run into issues when I tried to distribute objects.
Keyboard Placement/sizing: I don't really know what to call this, but I have become accustomed to being able to enter the coordinates or the size of things on the keyboard. I found now way to do this in TinkerCAD.
No Cloning: Now that I've seen the power of cloning in Inkscape, I am looking for the same thing in a 3D modeler. In this particular exercise, I would have used it to create one tile and then I would have copied the rest of the tiles.

I am sure there are many other limitations, but given my limited experience, these were the ones I ran into.

Here's the final TinkerCAD sketch of the bounce-back that I'm hoping to use for my final project. It's rudimentary, but given it's the first time I created my own 3D model (rather than downloading or scanning one) I figure it's a good start.

TinkerCAD bounceback

I found TinkerCAD easy to pickup, but it probably won't be that useful as my models increase in complexity. Having said that, I did find a new function that could be really useful to me at school...Export to SVG. Apparently, once you have your model you can export parts to a 2D SVG file, which can then be laser cut.

Rhino

Wow. Rhino looks bare bones, but it actually looks pretty impressive at the same time. Because it looks like the first "real" 3D modeling program I've every tried to figure out, I decided to start by looking at other models in the program. I figured seeing examples of what others did might help me understand some of the underlying concepts. One example that I choose to play around with was a TinkerCAD complex model that someone else had built. It's a battleship. And using this model, I was able to learn about the basics of Rhino. I was also able to learn about the difference between

Battleship model (exported from TinkerCAD):

Battleship STL

Then I decided to try to edit a model to see how it handles "MESH" and the 3D models. I haven't done much of anything with these, but I realized it might be worth trying to edit a 3D scan I'd done of a Dunkin Donuts coffee mug. I also wanted to test whether a model scanned with the MakerBot Digitizer would be editable in Rhino.

Dunkin Donuts Coffee Cup (scanned in from MakerBot Digitizer):

DDCup in Rhino

The thing that's interesting about this model is that it has a flaw...on the top you can see that it didn't scan well. So, while in Rhino, I tried to fix the model (hence the hole in the top right perspective view). It turns out that the mesh

I ended up finding the following tutorials that I am now going through...

All in all, while I didn't become an expert in Rhino and didn't end up creating the same bounce back model in Rhino, I found myself immersed in becoming aware of what's possible with it. Based on this, I've decided that Rhino is going to be my tool of choice for all 3D work. It seems to be much more powerful that 123D, TinkerCAD and SketchUp in that it looks like it will allow me to create 3D models AND cleanup scanned models. I haven't found a way to do both of those things with any of the other tools I've played with. I also found that there is a deep set of materials available for it, which admittedly is true with the other tools.