So I've always wanted to build a mechanical iris, and this 3D design contest sounds like the perfect way to work the bugs out.
We'll call this step 0 (maybe? it is my first instructable...) - Research! You need to figure out what you want to make and if its ever been made before. What problems they have had, or success stories. So hit up google images and search for mechanical iris.
the first image is what i actually ended up with!
Disclaimer: I know the mechanical iris has been instructabled to death, but this is focusing on the CAD design of it, not the mechanism itself.
Step 1: Draw It!
Step 2: Check It
After I made sure it would function the way I wanted, I took the time to focus on how i would make it. Since I haven't wont the replicator yet, I would have to make this by hand. look at all those complicated cuts? So I made a 3rd version with less intricate cuts.
Always remember that you can draw anything, model most things, but you're limited to what you can actually build. That's why I want a 3D printer!
Step 3: Solid Works Setup
Open solids works and make a part. Immediately save it. Now take the simplest component of the assembly and draw it very basically. In solid works you make a sketch, pick a plane, and draw it. After that you extrude it. This takes it from 2D to 3D.
I decided to use the outer ring as my template piece.
Once you have your template piece made, you can close the 3D program and copy and paste the file however many times you need it. My assembly for the Iris has 5 distinct pieces:
Remember that most 3D programs are parametric. That means you can draw it with any dimensions, then click on "smart dimension" and give it the size you need.
Step 4: Draw Your Parts
Step 5: Make Your Assembly
Step 6: Put Everything Together and Mate Them
Next you add another piece, I went with the outer ring.
As you add parts and mate them, you'll probably want to make some changes to them. That's ok, just right click on the part in the tree to the left and click open part. Make the changes and save the part. when you go back to the assembly it will tell you that it was updated and make the changes. Isn't technology wonderful?
Step 7: Paterns
The same trick works for parts if you want to pattern a feature, like the holes around outer ring and back plate.
Step 8: Go Make It
So built it the old fashioned way. Redrew it on foam board and cut it out. I used pins as hinges.
I'm not impressed with my construction skills (now you know why I changed the design from v2 to V3), but it mostly works.
Step 9: In Closing
But it was fun, I'm glad i did it even if I don't win the contest.