kent watson nose ring

During the last couple weeks I've been working with graduate student, Kent Watson, on some projects that he has been wanting to do. I have been so bogged down lately with administrative duties, that it's nice to have time to just work with the grads discussing ideas and making some things. I helped Kent 3D scan himself in a toy army soldier pose and then we 3D printed this. He was hoping to see what reducing the scale in the print would do to the low resolution scan and how this might actually create a object that appears to have more detail at a small scale. I helped him with getting a makeshift rotisserie made to facilitate this project. Then the next week we worked on making a sand cast from his 3D printed nose. In the following days I taught Kent how to use the lathe to make an aluminum ring that he could attach the cast nose to. Kent has been getting a lot of internet press for his "nose ring". Kent is a hard worker and I am glad to see him in the DCRL working all the time. I think he realizes that his production and thought process requires constant making and investigation. Glad to see him getting a little press.

DIY 3D Printing

3ders

Mashable

readymake: metal casting (knight)

We repeat the process for each piece.

readymake: metal casting

John and I cut up some scrap bronze and then loaded these clean pieces into the electric melting furnace that I have. We could have easily melted some metal in a crucible with an torch, but I thought it would be easy to keep restocking the furnace with fresh bronze and we would have molten bronze available each time we were ready to pour a mold.

The crucible on this furnace is made of graphite that can be replaced as it wears down from repetitive melting sessions.

 The temperature can also be digitally controlled.

Once the metal is up to temperature, we are able to pour molten metal into the mold. Once poured the metal solidifies fairly quickly. I wait for the button to stop glowing and then I am able to split the mold. 

 Care must be taken as the heat from the metal has transferred through the sand and to the metal flask. Usually I would wait a bit longer to open the mold, but we were looking to produce these quickly, so we opened the mold right away. You will notice a dark shell of carbon like sand surrounding the part.

 I tap the button of the piece against the concrete floor and this shell crumbles. It is actually good to lift the piece and shell out of the mold intact as that keeps the sand mold free of the chunks of black hardened sand. The sand in the mold flask can then be put back with the excess sand from in the molding pan and chopped up to be used on the next mold. Just make sure to discard any of the hardened and black sand as this will contaminate your good sand. 

 The final cast piece can have the button and sprue cut off and then that material can be remelted and used to cast the next piece. The cast piece can be pickled in avery diluted sulphuric acid solution to clean any impurities that are on the surface of the piece. Now it's time to finish the piece....

readymake: sand molds

My studio assistant, John McGeen, and I started making molds from the Duchamp Readymake chess set on Thursday. You can see that we started with a cast iron flask with cope and drag halves. This particular mold has an opening formed into it for a pour hole and "button". It uses rolls pins for the indexing of the cope and drag.

For our "sand" we are using delft clay for the molding process. 

I usually figure out where my parting line will be and then I create a board (with a cutout in the sale of the piece at the halfway mark) that will establish that parting line in the object and I can ram the sand on top of that board. In this case I wanted to do this quickly, so I ram one half of the mold and then strike off the back side of that half, flip the mold over and then physically press the object to be molded into the smoothly packed sand.

I press it deep enough to be at the halfway mark of the chess piece and am careful not to let the piece "roll" toward one side or the other. You want a direct downward pressure if you are going to mold something in this "ghetto" fashion. I have also established that I am going to pour the piece from the bottom up since the opening in my flask will feed the flow of metal from bottom to top in the piece. I also am careful to situate the piece fairly close to the opening so I can keep my sprue or gate channels short. If these gates are too long the metal might "freeze" before it fills the mold. In the case of these small pieces and the fact that I am doing this quickly, I do not put any vent passages into the mold as I would with a larger more critical piece.

Once the piece has been pressed into one half of the mold, I dust the surface of the mold with corn starch (baby powder or talc would be a fine alternative to the corn starch). The powder will keep the sand from sticking to the part and the sand when you ram the other half of the mold.

I make sure and chop the delft clay very fine so that I am able to place fine powder directly on top of the part. The first layers of sand are delicately rammed and then I am able to continue to place more sand into the mold.

After that side has been fully rammed, then I strike the back side of the mold off.

Next, it's time to open the mold by placing a wedge on each side of the mold where the roll pins are and carefully work both sides until the mold is split.

I carefully lift one side of the mold off and then proceed with cutting gates into the sand that will feed metal to the piece to be cast. I am able to carefully extract the chess piece that is being molded and I am careful to watch for any small pieces of sand that can fall into the mold. I make sure that the passage way to the gates is clear and tapered so that the piece will have a smooth flow of metal into the mold. 

Once everything has been checked for small pieces of sand or particles, I'm ready to close the mold up. The two halves are brought together and then I use two pieces of wood to clamp the mold half together with a c-clamp. The force of the molten metal can sometimes cause a blow-out or a bulge to form, so the wood will keep constant pressure against the exposed sand in the mold. It will also make sure that the cope and drag are held tight against each other to reduce the potential of flashing (or a thin sliver of metal formed usually at the parting line) to occur. Now we're ready to pour some molten metal...