Molding and Casting¶
Group Assignment
- Review the safety data sheets for each of your molding and casting materials
- Make and compare test casts with each of them
- Compare printing vs milling molds
Individual Assignment
- Design a mold around the process you’ll be using, produce it with a smooth surface finish that does not show the production process, and use it to cast parts.
Learning Outcomes
- Design appropriate objects within the limitations of your process
- Demonstrate workflows used in mold design, construction and casting
Have you answered these questions?
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Linked to the group assignment page and reflected on your individual page what you have learned
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Reviewed the safety data sheets for each of your molding and casting materials, then made and compared test casts with each of them
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Documented how you designed and created your 3D mold, including machine settings
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Ensured your mold has smooth surface finish, that does not show the production process (by postprocessing if necessary)
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Shown how you safely made your mold and cast the parts
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Described problems and how you fixed them
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Included your design files and ‘hero shot’ of the mold and the final object
Group Assignment¶
You can access the link to my group assignment here.
Individual Assignment¶
Go through my week 13 vocabulary and software page to get familiar with the new terms this week.
Designing¶
For this week’s assignment, I plan on making a minecraft flower and my current favourite emoji😔 I will be using the 3D printer for the laser cutter and the monofab srm-20 for the emoji.
Minecraft tulips design¶
This is the inspiration from Pinterest.
To start designing, open Fusion360 and create a sketch like so.
Extrude the rose by 7 mm. Draw a rectangle around the sketch, fitting the rose inside, which is not too big nor too small. Using the ‘offset’ tool, drag another rectangle, 4 mm away from the original rectangle.
Extrude the inner rectangle by 2 mm.
Extrude the outer rectangle by 10 mm.
Now, you are ready to 3D print it. Go through my week 13 documentation here to learn how to 3D print if you are not already familiar with it.
Here is how it looks like after it has been 3D-printed.
Pensive face emoji¶
Using the canvas tool, I imported a picture of the emoji from Google as reference for my design.
Next, drag out a sphere.
To draw out the outline of the face, I used the Control Point Spline
This is how the sketch turned out.
Extrude the sketch of your face outline after you are done and cut it through the sphere.
Cut out half the sphere as well so that the base of the emoji can be flat. This is the final result.
Milling¶
I am going to use Roland SRM 20 milling machine in order to mill my wax box. The drills I will be using is the 1/8 ball drill and the 1/8 square drill. It typically has 2 main stages- roughing and finishing.
Roughing pass: removes the bulk material quickly in very fast and aggressive cuts. It gets the wax close to its final form. It uses the 1/8 square drill.
Finishing pass: this is the final process where we get to achieve a very detailed and smooth surface. It is slower and provides a more precise cut. It uses the 1/8 ball drill.
NOTE: DO NOT FORGET to use the correct drill. Otherwise you might mess up your work.
Modela Player 4
This software is used to generate g-code for the SRM-20 machine.
Open the software > tap on file > open > select your stl file > select the material as modelling wax > tap on ‘new process’ > click on roughing.
Under tool, select the 3.175mm square.
After that, set the start height according to your design. I set mine to 5mm.
tap on next.
Again, tap on next since you do not have to edit anything here.
Tap on Finish and you are done with creating the file for your roughing process.
Next, we will do the same for finishing.
Select the 3.175Ballnose as the tool.
For the start height, remember to set it as same as the one you set while making the roughing file.
This is the toolpath generated for my design.
Finally, you can open Vpanel and start milling your design.
RESULTS!
Molding¶
To make your mold, here is a list of components you need.
NOTE: Instead of the SORTA-Clear (material for making the mold) as shown in the above picture, we will be using LOCZEST Liquid Silicone Rubber (LSR 110).
We will be using the weighing scale shown below to measure both part A and B equally since they need to be mixed in equal volume(or mass).
Pour out the soultion from Part A and measure its weight.
It is 21.3g. This means that the solution from Part B should also be 21.3g.
After you have made sure that both of the solutions have the same weight, bring it together in one larger container.
Mix them well.
After mixing it for a good amount of time, pour it in your mold box.
Wait for it to set for more than 4 hours.
Demolding
Demolding is the process of extracting the mold from your design. Here is the result of mine after demolding it.
PICCCCTUREEE OF EMOJIII ALSO
Casting¶
The casting material that we will be using is the Smooth-Cast 305.
Now, let us start by mixing the 2 solutions in 1A : 1B ratio. This is what the 2 solutions look like in equal ratio.
Now, mix it well.
Pour it in.
Let it sit for an hour or so.
Results¶
This is how the pensive face emoji turned out. I guess it’s alright(right?).
Failure¶
My tulip did not turn out that great in the first trail because I realized I had not filled the material to the brim, which made it turn out quite thin, making it break😭
However, my second try was good though. so yay.
Original Design Files¶
Thank you!
The template for this website was provided by Mr. Anith Ghalley and used with his permission