Ornament in 2.5 Dimension [Analysis]

A bit late, but wanted to make sure we got this up.
Here is our analysis of the underlying geometry study that went into the creation of our Assignment 1 pieces. It moves from the basic conception of the eggcrate form to the final resultant geometry rendered by the endmill.

Safety First!

I think we need one of these slides every semester.

Vaccuforming Viper's Vaccuforming Experience

Silicone casting tutorial session pictures step by step.

VacuumForm [Post 3]

Final Pieces


Test 1


Test 2


Test 3

I have also posted all the additional process and final images to a flickr set here.

VacuumForm [Post 2]

The sagging of the PET-G proved to be extremely important to the quality of the resultant form. In the first two tests, the PET-G was allowed to sag between 4" and 6". But in both cases, the plastic popped at one of the large openings. We assume this was a result of overstretched material. In reality, the condition of each egg-crate opening is the same as the metal frame which holds the PET-G; the plastic is stretched through the heating process, then stretched again between each rib of the formwork. In order to compensate for this, we only let the PET-G sag to approximately 2" to 3" before removing it from the heat. This proved to be an improvement, as we didn't have any blow-outs, but still got moderate deformation through the fromwork.

[TEST 1]


Depth of slump at removal


Depth of slump at placement


Placement into formwork


Pet-G in formwork during vacuuming

VacuumForm [Post 1]

For the first part of the process, we had to make a few revisions to out egg-crate, as it was slightly oversized. However, this imperfection made the manipulation of the form that much easier. So when vacuum-forming each trial, we were able to remove and rearrange pieces with minimal headache.


Cut down eggcrate

One of the interesting things we found during the heating process was that the Pet-G would begin to sag and distort, then stap back to tension. We guessed this was probably do to uneven temperatures accross the surface of the plastic. It appears logical that warping would occur until surface equalibrium would allow for an even and consistant slump.


Initial distortion


Surface equalibrium


Begining of sag


Approximatly 3" sag depth

eggcrate caustics

caustics formed by blue video projector light through PET-G vacuformed into an eggcrate formwork

if you missed the tutorial on monday....

assignment_casting

Casting Day [post 3]

Here is the final cast from the first mold. The texture from the frayed mold proved to be pretty interesting, and adds a nice contrast to the coffering. It will be interesting to see if we like the results from the smooth and correct mold more or less than these.


Final cast


Texture detail


Detail of corner texture


Comparison of mold and resulting cast

Casting Day [post 2]

Here are some process images of the casting party. I kind of forgot to take picture until we were done pouring, but Gustavo and I plan on pouring our second mold as well to compare the difference in texture, so I will make sure that process is well documented.


The aftermath of mixing plaster


Plaster curing in mold


Removal of phone mold from plaster cast


Removal of phone mold from plaster cast


Final plaster cast

Casting Day [post 1]

So here are some images of one of the final molds. The form was milled using a 1/2" spherical bit. I pathed it to take one rough pass leaving 1/2" of material. However, on the final two passes, the speed of the mill proved to be a bit high. Much of the surface was frayed. Because this is more of an experiment, the accidental texture is a nice side effect which should interesting in the final cast.


The final mold.


Detail


Detail showing the obvious fraying


Detail

Mixing Plaster

So here are some things I've learned through my experiences with plaster.

This site is a bit cheesy, but is pretty good at explaining a good process to plaster mixing.

- Mixing Plaster -

Though he goes through a lot, the most important point is the "Islands Method." But in my experience, this is just a good concept to have in mind, but not a scientific process to adhere to. Trial and error seems the best way.

Also, in this casting process, it's important to use a release agent, otherwise your plaster will adhere to the blue foam. While you can buy manufactured release agents, the best and cheapest thing seems to be green dish soap. Diluted with some water and applied using a spray bottle, you can get a really even coating. Let it dry for a bit, and your good to pour.