12. Molding and casting¶
Group assignment:¶
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Review the safety data sheets for each of your molding and casting materials
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Make and compare test casts with each of them
To see our group assignment click here
Individual assignment:¶
- Design a mold around the stock and tooling that you’ll be using, mill it (rough cut + (at least) three-axis finish cut), and use it to cast parts.
For this week I decided to make a mould to make a little rabbit.
To achieve this, we divided our work into several parts: designing the countermold, cutting the countermold into several parts for 2.5 D machining with the Roland SRM-20, making the molds and finally creating the little rabbit. 🥰️🥰️🥰️🥰️🥰️
COUNTERMOLD DISING ¶
To design my counter-mold, I downloaded the .STL file of my little rabbit from the printable website.
Then I made a mesh in order to prepare the piece for the counter-mold.
Our rabbit is now ready we can start with the contours of our counter-mold.
Then we’ll outline our contours
We’ll use the mirror tool to make the opposite side of our mold.
Now that we have all the faces of our mold, we can export it in .STL file.
PREPARING FOR MACHINING ¶
To prepare for machining, we’ll use vcave. To begin with, we’ll import our counter-mould.
Next, we’ll center the part
We opened the stl file of our mold with v-carve and set the import parameters as shown below :
Once the import is finished, we proceeded to the generation of the toolpaths. To do this we used the “3D Roughing Toolpath” option for the roughing and the “3D finishing Toolpath” option for the finishing. To generate the roughing toolpath we proceeded as follows.
We proceeded in the same way as below to generate the finishing toolpaths. Once the toolpaths were generated we proceeded to their registration as indicated below.
ON THE monoFab¶
At y’ello lab, we have 3 different sizes of machinable wax, as you can see below (this image was taken from the website Karam Khrais).
Here’s the tool we’re going to use 1/8.
To find out how it works, see our week04
REALIZATION OF MOLD ¶
For the production of the negative molds we used SORTA-Clear 37 silicone mold rubber.
Caution: chemical products for molding can be dangerous for your health, for this reason there are safety rules that must be respected. we have selected the most relevant ones for us for more details click here
For the use of SORTA-Clear 37 silicone we have referred to the technical data sheet from which we have derived the essential information below.
After following the instructions for mixing and pouring the SORTA-clear 37 silicone we obtained the following results.
REALIZATION OF PIECE¶
For the realization of the positive molds, we used Smooth-cast 300 Series.
For the use of Smooth-cast 300 Series we have referred to the technical data sheet from which we have derived the essential information below.
After following the instructions for mixing and pouring the Smooth-cast 300 Series we obtained the following results.
As you can see, there are quite a few bubbles in the mold, due to a mistake on our part. When mixing the two products, turn the mixture in one direction only, to avoid too many bubbles. If you have a degasser, use it; unfortunately, we didn’t have one in the lab. Given the bubbles in the mold, the most important thing to remember is this: if you mix the product in all directions, there will be bubbles!
RESULTAT ¶
