Incorporation of Design and Manufacturing Principles:

In our design, we have taken into consideration several design constraints inherent in injection molding and vacuum forming. They center around challenges with warping, extracting the finished part, and making sure our tolerances allow for a functional finished product.

We have decided to use two thermoformed parts as the detailing of our yoyo instead of trying to overlay an injection molded piece with windows and an inner thermoformed piece. This decision is the result of conversations with the lab instructors describing the probable difficulties with the sharp corners and tight tolerancing we want for our yoyo.  With a thermoformed part only, we will be able to achieve the intricate details we want, and we have decided that painting with a stencil will be the best method for adding more color to the design.

Injection Molded Base:

We have attempted to have this part as close to a uniform thickness as possible, in order to decrease non-uniform cooling and, therefore, decrease warping.

In order to have a press fit, we have toleranced the ring acceptor to be slightly smaller than the diameter of the ring itself in order to have a reliable press fit.

Ring:

We have oriented the draft angles such that the slight chamfer helps guide the ring into the receiving pocket of the injection molded base, while maintaining maximum efficiency for removing the part from the mold.

The mold has been adjusted for shrinkage.
Furthermore, we have toleranced it in accordance with the injection molded base such that it will always have a press fit.

Thermoformed parts: For this, we have decided to drape our plastic sheets around an extruded mold rather than pull the plastic sheets into a pocket. This is because we have several sharp corners in our designs, and these corners cannot be machined as a pocket due to the tooling we have access to. If we machined a pocket, every corner would have a fillet matching the tool we used to machine it.  We can negate this by machining material away around the desired shape rather than machining the desired shape (as a pocket) out of a solid piece of aluminum.

Furthermore, we will be ensuring that our parts can come off the mold by applying the appropriate draft angles to the extrusions.

For creating the mold dimensions themselves, we took our original sketch in solidworks and used offset entities to account for the plastic thickness.