I’ve been working away at diagramming our molding process. The first image represents the molds of our “Strongback” Hub Tile.
This image represents the molds of our pinwheel tile, which creates our variations through rotating by specific ammounts (30°, 60°, and 90°)
In our final presentation, these will go alongside a few other diagrams that will display a few of our ideas for arrangements of these tiles. We can’t build them all, but we can certainly show many of the possibilities.
Our final molds in action and the tiles that are resulting:
So far the molds are holding up famously. We’ve wrapped the “inside” aspects with black plastic to resolve a release concern and the effect is a very shiny and plasticized interior, or hub, of our core tile. We had worked on differentiating the “inside” and “outside” surfaces of the tile and this pragmatic production decision carries this surface treatment forward.
The added benefit of transparency This has allowed us to greatly reduce the occurrence of voids and the resulting failed pours.
After fifteen casts the mold, both MDF and PETG elements, are doing very well.
Some of the tiles that have been cast: hub tiles on the left under the monitor, core tiles in the center, and the molds on the right.
The hub tile has received the same “plastic” treatment on it’s center element. Here it was purely out of functional necessity so that we could release the cast from the mold without compromising either.
Though the tiles will require some light cleanup, the interior webs of plaster that slip easily into the plastic-wrapped crevices create a very interesting effect. It would be possible, using a ridged form such as the MDF and PETG here and a plastic barrier, to control the degrees of opacity. We’ll try a dry run assembly of our wall and evaluate then whether or not to leave the happenstance membranes.
The process of building our final forms involved a process of casting all the “pieces” of our iterative tiles in order to vacuum form the various mold sections. Each of these castings, pre-vacuum form, provided an opportunity for further editing and refinement.
Speeding up the drying process. This works great for items which are simply acting as molds for vacuum forming. We did see some hairline cracking which would concern us for final product curing.
The oven drying permitted sanding within 2 hours of casting. Oven drying was done at 225*F. Sanding provides a uniform fit between mated-halves and a variance in surface between the inside- and outside-faces of the core tile.
The four aspects of the core tile’s mold. The top two have been sanded smooth and for the interior of our tile, the hub side. The bottom two are the front and back faces of the core tile and still retain much of the hand-tooled “brain” texture of our earliest exploratory castings. The brain texture has undergone a level of refinement in that each stage of vacuum forming (two prior to this final) removes a level of micro-detail.
Given the sheer number of vacuum form iterations we’ve gone through we began reusing sheets to reduce costs. We noticed that there may be a brittling effect to this so beware the fragility of reused PETG.
Even the reused PETG provides a clean final form. the plaster here is waste.
The PETG form is then nested in MDF to which it is glued into a solid assembly.
The voids between the PETG form and the MDF armature were then filled with an expanding poly foam insulation. This effected to lock into place the PETG parts which would allow the core pieces to be cut apart for post-cast disassembly while maintaining a consistant realignment.
The mold for our hub tile clamped to glue the PETG and MDF components to each other.
Here are some more renders/models of my hub tile. This time, I tried to reduce the mass of the piece to make it lighter. I also started playing around with some of the rotated tiles and seeing how they would mesh together 3-dimensionally. I want to be able to design two patterns that overlap predictably. My working hypothesis was that these pieces would accomplish this.
I found that the easiest way to make these tiles meet up on the other side is to have them rotate 60 degrees, if at all. In this way, the geometry seems to match up.
I realized that these tiles don’t fit together as easily as I’d thought they would. I tried to make the layers more than two-deep. As you will see this created a complex shape that was difficult to capture and display to my satisfaction. Also, the idea of overlapping patterns seems to get lost when the assemblies are taken to this length.
This next arrangement I worried less about how the structure of the assembly would function and instead just built out into space. I was determined to make these overlaid patterns work. I found that if I was careful and consistent, they could be coaxed to meet up more like I was hoping. This “snowflake” has 3 layers of complexity to it.
In the end, I really do enjoy the options available through the use of this tile; that being said, my group has elected to pursue one of several other designs involving a 3 sided hub. Many of the earlier designs can also actually be accomplished with only these types of hubs.