1. Design
As a modering assighnments, I thought of using local characters. This character is the original character which the nearby town has. The name of the character is
"nezukon".
"Nezu" is the meaning of rats in Japanese. "Kon" is the meaning of radish in Japanese. Spicy radish is a special vegetable of this town, it is a character that imaged it.
Our Fab works with this town and is working on product development utilizing "Nezukon". Therefore, I decided to set "Nezukon" as a molding and casting challenge. Finally I decided to make it a sample of chocolate or ice making mold.
Designed using Fusion 360, I designed two molds, the upper mold and the lower mold. I set three dowels so that mold matching works well. Pour spout was set so that chocolate can be poured from the bottom. The files output in the STL format are as follows.
2. Cutting
I used roland SRM-20 for cutting. Modeling wax was used as a material for cutting. A 3 mm diameter squared mill was selected for rough cutting. For finish cutting, a 1.5 mm diameter ball mill was selected.
Roland's Modela Player 4 was used to create cutting data. First I set up rough cutting. Cutting conditions for rough cutting are shown. The XY axis was set to a speed of 24 mm/sec. The Z axis was set at a speed of 10 mm/sec. The spindle is 7000 rpm. As a simulation of cutting, the processing time was estimated to be 53 minutes.
Next, finish cutting was set. In order to check the difference in finish, the upper mold and the lower mold were set differently. For the upper mold, cutting on the contour line was chosen. Cutting conditions for finish are shown. The XY axis was set to a speed of 16 mm/sec. The Z axis was set at a speed of 16 mm/sec. The spindle is 7000 rpm. A fine finish can be made, but the predicted cutting time is 5 hours.
In the lower mold, scanning line type cutting was selected. Cutting conditions for finish are shown. The XY axis was set to a speed of 24 mm/sec. The Z axis was set at a speed of 24 mm/sec. The spindle is 7000 rpm. The expected cutting time was 36 minutes.
It is the picture that the two processing is over. It was confirmed that machining was performed as simulated. The finish of the contour line could be processed to details. The finish of the scan line also had multiple parts that were crushed.
3. Production of mold
Silicone rubber which can be used for foods was also used for molding. Unlike ordinary silicon, it does not contain tin compounds. It was confirmed that the hazardous substances were not contained in the analysis test table of the Japan Food Analysis Center. The standard hardening time is 6 hours (temperature 23 degrees). Two solutions A and B were mixed and poured into a cut mold. Since the room temperature was 15 degrees, I switched on air conditioning and adjusted to 20 degrees or more.
I confirmed it after 7 hours and found that it was beautifully shaped like a picture. Because it is silicone rubber, it has elasticity. The finished mold was cleaned thoroughly, and the upper mold and the lower mold were combined and fixed.
4. Casting
For the material to be poured, 30 g of plate chocolate was used. I boiled the water and melted the chocolate. Pour molten chocolate into the mold. After pouring it also fixed with a plate.
I removed the mold after 2 hours. The mold could be peeled off quickly. Burrs occurred because the cutting method of the upper mold and the lower mold was changed. Also, because chocolate did not flow to a part of the ear, it was missing. I should have bleed.
Although there was a problem in the finish, the "Nezukon" of chocolate was completed. Next time I would like to try making ice. I plan to make this a reference material for collaboration events between Sakakimachi town and our fablab nagano.
Archive
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3D data (Fusion360,STL)
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Cutting Data for SRM-20 (Modela Player4 ,mdt)
This week's assignment is over.
