Just a small update to keep the internet in the loop. I have completed the model board and all of the details associated with it. The photos I have aren't of it 100% completed, because my camera was missing for the week. However the finished cannon model doesnt look much different that what you'll see here, one system to key the mold halves together was added at the last minute, thats all.
Currently the plan is to cast the first cannon on April 3rd at the foundry in Tierp. They are currently fabricating the flask system that we are going to use to pour the mold, which involves some fun complexities that I will leave as a surprise for later.
The model board also has its indirect sprue system attached to it, we decided upon this system as its a little safer and we can't bury the mold in the ground, so we want the mold to have as little issues with hydraulic pressure as possible. Also using this method reduced the amound of mold erosion that will take place while we fill the mold in a speedy forty seconds!
Now the time has come to start putting all of these pieces together! This is what is called a model board, and ours will consist of two boards which are mirror images of each other. The exterior dimensions of the model boards are 3.5 meters by 1.22 meters. These two boards break into two smaller pieces so that we can fit them in our elevator here at the museum.
This is the simple part of the setup, this week will be all of the additional keys will be added to make all of these parts register properly, and final dimension adjustments, and the bracing of the backside of the mold.
One of the pieces I had made ended up undersized, which led us to figure out how to do some dimensional editing! Of our options, I figured that the fastest way to make the piece larger and appropriately tapered, would be to run plaster over the surface of it. This would be fast and material efficient, the other option being turning a whole new part.
This is achieved by creating a jig that spins on the parts central axis. This consists of a piece of plastic with the profile of the part cut into it. This plastic piece that turns on the central axis is run through plaster as it sets to create the additional width we needed.
Hello everyone, we are back with the continuation of the ornamentation! There are two more molds to make, but this week I was able to make four of the six silicone molds. The molds are a pourable silicone, the same that was used for the blanket mold for the dolphin.
Then a polyurethane plastic was poured into the mold, which has the consistency of car tire rubber. This allows us to possibly not need to cut apart the turned objects that I made to make them draft correctly. Now they can just be placed on top of the turned pieces, and then have the mold packed on top of them. After which they can just be peeled out! Much simpler for me and the the foundry!
Also, some bonus shots showing my ornamentation interpretations next too the beat up originals on the cannon, just to show you what I've been working with.