13. Molding & Casting

Designing an Eyeball

I was impressed by this instructable on making realistic resin eyes using 3D printed parts, so I wanted to adapted the author's process to fit the requirements of this week.

I designed a simple eyeball using Fusion mostly using spheres. A cavity was made in the eyeball for the iris. The hollow cylinder at the center represented the pupil. The pupil and the iris would be painted before I apply clear resin on top to fill the cavity.

Designing the Positive Mold

First we have to design a 'positive' mold of the 3D model that will be machined on wax, which will in turn be used to create the 'negative' mold using silicone, which will be used to create multiple copies of the eyeball

Draft angles of 1 degree have been added to the walls of the mold and 2 degrees have been added to the registration marks.

I have tried my best to provide at least 6 mm space to allow the large bit reach and remove most of the material in an effort to reduce machining time.

Computer Aided Manufacturing (CAM) in Fusion

Now we will use the CAM tools inside Fusion to generate the toolpath we want.

To use CAM, we go to Manufacture Workspace. I added the tool library from

Then we go to Setup and set the work dimensions and the XYZ cordinates

Then we set a tool operation (Adaptive clearing in my case), set the tool (6 mm 4 flute clock wise in my case), set the coolant to 'Disabled' and set the speed & feed rates that were selected based on previous experience by the instructors for the machine we are going to use

Then we adjust some parameters in Geometry; 'machining boundary' to 'selection', 'tool containment' to 'tool inside boundary' and 'ignore stock less than' to '0.5 mm', select the inner rectangles,

Then we go to Passes and set the optimal load to 50% (ie., 3mm for 6 mm bit), 'Maximum Roughing Stepdown' to 10 mm and Stock to Leave to 0.5 mm if not already set.

Then go to Linking, adjust retraction to minimum, amd make sure Ramp type is set to Helix, and a Ramp angle of 2 degree

Then I generate the toolpath using Ctrl+G, and simulate to see the result.

Then I added new Pocket operation using the same bit to clear the holes for the registratin marks, I set Ignore Stock to 0

Error while trying to do Pocket operation. See Mistakes & solutions to see how the error was solved

Like this I completed all the CAM operations

Then I go to Actions > Post Process and export as .gcd file. I can club multiple processes if they use the same bit

Machining the 'Positive' Mold

The positive mold will be milled out of Machining Wax

Machining the 'Positive' Mold

The negative mold will be madew by puring silicone into the positive mold

Making the Eyeball

The negative mold will be madew by puring silicone into the positive mold

Detailing

I wanted to add paint to detail the iris and the veins

Adding Resin

The plan was to pour transparent resin into the cavity that I made for the iris

Adding Resin

To add some finishing touches, I wanted to make the eyeball look glossy to make it as realistic as possible

Conclusion

References

References to help reader understand in detail

How to Make Ultra Realistic Eyes Using 3D Printing and Casting (instructable)

Design Files

Click here to access the design files