These molds are done (almost)!

We finished our first renditions of the molds last week, and immediately we decided to test out our wind turbine mold. Using the injection molding machine, we made at least 30 different wind turbines at different injection molding settings. We modulated shot size, cooling time, and holding time to determine what would be optimal when we create our actual yo-yos.

We ran into a few problems:

1. No matter what settings we did, the wind turbine got stuck to either the core or the cavity, and we had to manually fish it out.

2. The runner would detach from the piece pre-injection because the channels were too small/weak.

3. Our circular insert was too small for the bearing (easy to fix because all we need to do is take out more material).

At the end of the day, we handled problem 1 by realizing that it was much easier for us to actually just remove the stuck piece in the core that was disconnected to the runner rather than having to twist the piece manually out of the runner. We specified settings for that.

We also removed more material from the center hole within the cavity to create a larger circular insert to make a tight fit with the bearing. More testing is needed to see if that worked.

Our outer casing mold was tested, but we ran into issues with regards to the injector pin locations. In attempting to create the right structure for injector pins, we shifted the design slightly within the block on the CAD. However, that resulted in problems.

The fix was to create a new outer casing mold (did not take too long because of not complex the piece was) where we first placed injector pin sketches on the CAD prior to shifting the design. That way everything was consistent. This still needs to be done this week.

Finally, we tackled the inner casing mold problem, an issue that has been the bane of Sustainbiliteam since it's conception. We plan to continue to remove material in order to create a smooth area for the extrusions on the core to match the inlets within the cavity for our shut off surfaces.

We expect to make final touches relatively soon to ensure that we can start building our yo-yos with ease!