Mike Wazowski on a Rocket Ship

Role: Lead CAD/CAM Designer for Rocket Mold

Skills: NX CAD/CAM, CNC milling, injection molding, cavity/core mold design, interference fits, metrology

This team project was a deep-dive into the world of mass-manufacturing, particularly of injection molded products. The challenge for this project was to design, create, and then mold two parts that would snap together using pins, and then fit together using interference fits. As shown above, my group decided to design Mike Wazowski, from Monsters Inc., riding a rocket ship, with fire coming out of the back of the rocket. My roles for this project were largely concerning the rocket design and making the cavity and core for the rocket. At the end of the project, my team and I produced 20+ complete sets, all including a rocket ship, Mike Wazowski, and some flames that all fit together using interference fits and pin-hole fits.

This is a side-by-side of the outside of the rocket and the inside of the rocket that I designed on NX. In order to make the rocket properly injection moldable, I added 3° of draft to every flat surface, make sure that the pin holes would not cause any sink marks against the outer wall of the rocket. Additionally, the rocket was shelled to be 0.125” thick all around, in order to be evenly filled when injection molded. Using these CAD models, I then simulated the tooling operations in NX to prepare for the CNC machine, which I used to make the actual cavity and core for the rocket.

After the rocket CAD models and the CNC CAM operations were completed, I had a rocket cavity and core that were machined on the CNC mill, as shown.

The Aluminum blocks that the mold was machined out of were provided to my team by our professor, and the cavity already had the sprue in place for the injection molding. This meant that I had to calculate where the rockets had to go in order to have the most efficient runner, and fill up equally and simultaneously.

As seen on the cavity (left), there are two runners. This was caused by a miscommunication on the team, resulting in the peg sizing not being consistent between the cutoff and the peg for Mike Wazowski. The peg for Mike Wazowski was too large, and to fix it we needed to make the cutoff in the cavity larger as well. This then resulted in a cutoff that was too large, and cut off the plastic from filling the rocket whatsoever. To remedy this, I carefully measured out where the new runner would have to go, and I used a conversational mill to mill out a new runner. This runner worked with the machine, and my team ended up with 20 rockets that fit together with pin-hole attachments, as shown.