Week 0 - CAD
Constraints and parameters
We start the class with CAD. I have exprience using CAD, but mostly Autodesk Inventor. I Have dabbled a bit with Fusion 360, my lab works with SolidWorks, and my friend has been telling me to use Blender for a long time. So I will compare these three programs.
Starting off with Fusion360, I decided to make dice. My project idea is to make electronic dice. I've thought about it for a while, to have dice that you can throw but also do the math for you when you play a tabletop role playing game like Dungeons and Dragons. Theres some in the market but they've always seemed clunky and lame, and I want to do something coool. However, I'm worried about space for electronics and also the balance of the dice, I would hate to make something cool but its always skewed toward some value. completely ruining the randomized experience. Making a 3D model of the dice would be the first step toward something cool.
I started off with a 6 face dice. While I have done CAD, I feel like I am warming up and trying to get my muscle memory back, since I haven't done any complicated CAD modeling lately. I hope this class helps me do more of this so I feel more confident in my design skills when it's over. I created a sketch, made a square and made sure that the lengths of the sides were parametrized with each other by using the values of d1.
After this, I needed to make the dots for each face. I decided to dig out a half sphere to represent the hole instead of just using the hole feature and have it be cylinders. For this, I would use the revolution tool. I need a plane in the middle, so a created a new plane using the offset plane tool. I used parametrized values to offset it at exactly the half of the cube. Which this plane, I created a new sketch. In this sketch, I drew a sphere and made sure it as completely constrained.
I made the whole sphere do a 180 rotation along its axis to create a pocket in the cube. This would be the 1 hole face.
I switched my view around to the right face, then created a sketch on the face itself and made a new circle, using the same parameters. Then I made a copy and made sure the distance was also parametrized. The revolution proved to be a bit too timeconsuming for me, so I just sytarted extruding into the cube to leave the cylinder holes behind..
With the 1 in the top and the 2 in the right done, I checked online which faces normally are next to each to the dice. I switched to the back where the four goes. I created a sketch on the face, made a circle in the corner, and dug it out using the same method I described before. To make the other three, I used rectangular pattern with 2 and 2 to make sure we ended up with all 4 holes.
Then I turned to the front, to create a new circle in the center and use a rectangular pattern in a diagonal to make the other two holes an have a the three on the dice.
For the left face with the 5 holes, it was a similar process as the three holes, but using the other diagonal.
And the last face is the bottom, that is supposed to have the 6 holes. This one is another easy rectangular pattern.
While this all leaves uss with a cube that has all 6 sides, it is still kind of sad looking. The first hole was a true sphere, but the rest were sad cylinders. That's when I realized I could do something about those features. I decided to use a fillet in all of them, carefully choosing the lower ring of the cylinder and bringing it in. This made all the holes look just like the first one, at a fraction of the time and effort spent revolving them.
I then decided it was necesary to fillet all the edges of the dice so it wouldn't look so pointy and be a possible hazard to everyone. With this, it looked finished and polished and ready for rolling.
So I decided to tackle the next die, a 4d. This dice has 4 faces, and each face has 3 numbers and depening on which one is pointing up, that is the number that was rolled. I started with a equilateral triangle. Then I did a plane offset to the distance same as the sides of the triangles. Then I did a sketch there, finding the middle of the triangle.
This allowed me to loft the base triangle to the middle point in the offset plane, creating the perfect and parametrized pyramid of your dreams.
Having the tilted faces of the pyramids make it much easier to just make a new sketch on each face. Then I could use the text tool to make each number. I could use the normal sketch tools to align the number's bounding boxes to the lines traced to the middle of the pyramid. This allowed to have each number facing the right way when the dice rolled. Once the text was in place, I only had to extrude in the numbers. This was the same for the faces, the only difference was which number went to which face, to make sure they all aligned with the same nuber pointing at each corner.
I finished this one off with fillets as well on the edges. No one wants to get stabbed by a 4 sided die.
And that was how to make d4 and d6 in Fusion. As the difficulty ramps up, Fusion and Solidworks might have a harder time parametrizing a dodecahedron, for example, while Blender would be very easy.