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When I started this week, I couldn't think of anything I wanted to make. Still being brain dead, I just made some shapes and cut them out of wax.
I gave up on this shape. It was dumb and uninspired from the start.
I have a bunch of these end caps I had made earlier (you can't buy an endcap for a downspout), and decided to try to replicate these with casting.
I decided to make a rubber mould of this shape, and try to cast out a bunch of them. Casting from a mould with a quick setting resin is MUCH faster than prining them all out in 3D.
I had a bunch of left over Body Double Silicone Rubber that was at its expiration date, so I needed to use it up. I made the moulds of the endcaps with this rubber.
I did an investment casting to make the rubber mould. I built a box of wood to hold the material. I then poured a 1cm layer into the bottom. After there is a bottom layer, i floated the endcaps on that layer.
Giving it about 20min to begin to set up and stiffen (yet still not remotely solid), I poured another amount of rubber to completely sumberge the end caps.
After it had set (about 1.5hrs), I cut into the mould using an X-acto knife. I cut in until I felt the endcap, and then cut around the shape at a slight outward angle, maintaining a feeling of the tip of the knife on the surface of the endcap inside.
I also added makeshift "keys" so that the piece I cut out fits back into the same place each time it is placed back into it's sister half.
I did the same on the other endcap model, but I forgot to add keys. I also added a small cut out in the left corner to allow excess material to escape
Durring the lecture, Neil ran through a few of the potential material options to use this week. I decided to try my hand at using Hydro-Stone since we had some in the lab and it was fairly inexpensive.
Following the mixing instructions by weight, I mixed up some Hydro-Stone, and poured it into my moulds.
After about an hour and a half, the spill-over and drips surrounding the moulds had fully hardened, and so I decided to remove them from the moulds.
This material hardens from moisture leaving the solution; I did not think about how much the rubber will impede the moisture from escaping the Hyrdo-Stone. I removed the caps to the moulds easily enough, but I noticed the Hydro-stone had not fully set up yet. I left them to finish drying for another 45min.
Coming back, and needing to leave the lab, I attempted to remove the seemingly hardened caps from their moulds.
As you can tell, they were a bit more fragile than I had anticipated. The wall thicknesses of the original are probably too thin for casting in Hydro-Stone, and would be better suited for a casting resin. I will stick to printing out the rest of the caps I need with the inexpensive filament we have at our Lab.