To make this bowl you will require copper fill 3D printing filament, Copper sheet 1mm thick and a sheet of 3mm acrylic.
Why make a copper bowl like this?
3D printing the outside section is a very quick and accurate means of production. You can create intricate designs in interesting materials that are easily built without the input of handcraft.
The traits of laser cutting lend them selves well to producing accurate press forms. Without the laser cutter a more traditional means of making a press form would be to hand pierce a thick sheet of acrylic and then file all the saw marks out at a 90 degree angle. It is much quicker to laser cut multiple sheets of acrylic and glue together and the finish of the edges can be much neater depending on your filing and sanding skills.
Using laser cutting for press-forming tooling removes the object from being entirely CAD made and introduces a more personal touch to the piece.
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Step 1: 3D print your outer bowl
Firstly you will need to 3D print your outer bowl using copper fill PLA filament. You can download a version of the file here:
Step 2: Laser cut your press mold for the internal bowl
You will need to laser cut a press mold to make the copper section of the bowl. You will probably need about 6 of these if you are using 3mm acrylic. You can download a version of the file here:
Glue your laser cuts together using super glue. Ensure each layer is clean first. Once you have glued the final layer, place in a vice and leave to set.
Part 3: Cut and anneal your metal
Cut a square piece of metal that overlaps the edge of your press. You should then anneal this to a cherry red color.
Quench your metal in cold water and place in the pickle to clean.
Part 4: Press form your metal
Place your press form tool on the bottom plate of the press. Place your silver sheet on top, followed by rubber and a steel block.
Press your silver. This may need to be repeated several times before your bowl becomes deep enough from the annealing stage.
Part 5: Drill and pierce your metal
Using a center punch, punch the metal from the back to mark each section you are going to drill. This stops the drill from moving around your metal and marking it by guiding it down a small hole. Then drill holes through your metal.
Thread your piercing saw tightly through one of the holes and pierce out the shapes of the lines caused by the press forming. Repeat this until you have cut out all the holes.
Part 6: File and sand
Using needle files, file the inside of the cut out holes as well as the outside edge until you can't see and saw marks.
Starting with 250 grit emery paper, sand the edges and the surfaces of the bowl in a circular motion. When most of the scratches are removed repeat this with 400 grit. I stopped here to give the bowl a more mat finish however move up the grades of paper to achieve a greater polish.
Part 6: Oxidize bowl
Run some warm water from the tap into a plastic container, enough to submerge your bowl. Add in a splash of liver of sulfur solution. Dip your bowl into the solution for about 30 seconds, remove and rinse under the tap. Repeat this until you hae happy with the finish of the bowl.