Trial 1

Owned by Jasmine Thind
Last updated: Dec 23, 2022
4 min read

The first trial is a headlight cover design. This design was very a simple design, with the curvature decided on using the front of the aerobody. Full headlight design is still in works, hence this cover is mainly just to test how thermoforming works.

CAD:

The headlight was designed using the general curvature of the front of the aerobody. I wanted to see how the machine would work with a curvature like this.

 

A loft mold was designed using the profile above so that the machine has a closed object to work around and pull vacuum over.

Trial Results:

For this trial small holes were drilled along the middle (the last part the plastic would touch). I drilled them so that they were wider at the back and smaller on top. We also used a few washers underneath the mold to help the air flow (to pull more vacuum). No mold prep was done on this mold.

Attempt 1:

For the first trial we taped up one of vacuum valves (this is because the shop vacuums we had were either too small or too big for the machine).

While performing this trial the oven was pretty warmed up and as the plastic was thin, the plastic was ready to be pulled down fairly quickly (we were not ready). This is something that must be kept in mind for next time, full warming up of the oven should be done (around 10-15 mins you will see it turn red - should be good then), only then should the plastic be pulled up and the person pulling it down should be ready after its been pulled up. The exact plastic thickness and heating time should be looked into beforehand. It should evenly be dropping down from all sides. Based on the trials thus far I would say a rough 2-3 inches of dropping down is good, but again based on the exact plastic thickness we should figure this out before to ensure the best results.

Like the above image shows, this was probably a little too much dropping.

The following pictures show the results of the first trial:

 

As can be seen although the edges were properly done there was significant webbing that happened. There are a few potential causes of this including both sides of the plastic not being pulled at the same time, the overmelting of the plastic, and also that the small electric vacuum was just not strong enough on it’s own.

Attempt 2:

For the second trial we taped up the shop vacuum we had in the bay to the suction valve with tacky tape. We also we pulled down the two sides of the plastic tray a lot more evenly this time, yielding better results.

The following images show the results:

 

 

This time around the vacuum pulled a lot better over the mold (probably because we had the second vacuum connected). The few problems were however, that the holes appeared on the plastic and the texture of the foam was also very apparent on the plastic. To deal with this we decided to do the entire mold process and then attempt the thermoforming for our next trial.

Here is an image of the the mold after these two trials. The texture has clearly been changed a bit after the process.