Molding and Casting




Week SixTeen.

Group assignment

  • Review the safety data sheets for the molding and casting materials.
  • With each of them you need to make and compare the test casts.
  • Individual assignment

  • Design a 3D mold and look for the stock and tooling that will be using, mill and cast it.
  • Learning outcomes

  • Design the proper objects with the limitations of 3 axis machine.
  • Determine workflows that will used in mold design, construction and casting.
  • This week is about creating molds!

    Design

  • For this week I decided to make a simple design such as heart by using Fusion 360.
  • First i try to make a design by myself, the result as showen below:
  • I created a box that will be as the stock for the mold.
  • The dimensions that will be used for the stock are the following:
  • Width (176 mm)
  • Length (76 mm)
  • Height (39 mm)
  • Then in the stock I created pockets with 30 mm depth that will help to place my design object which I split it in half.
  • Then I mirrored the other half of the design to be totally symmetrical.
  • I add two cylinders one of them will for casting and the other for air to emerge.
  • CAM

    The next step is to generate the toolpath by Fusion 360 Cam/manufacture.

    1. Creating the setup

  • I click on setup > new setup.
  • I selected the lower left corner as the origin point in the stock component.
  • 2. Adding tools

  • I add the tools by going to manage > tool library > add new tool.
  • I added two tools : 1/8 inch flat end mill and 1/8 inch bull nose end mill.
  • 3. The step

  • To remove the excess material of the taper edge I need to do the step below.
  • Use the 2D adaptive clearing operation
  • go to 2D tab > adaptive clearing.
  • To clear the horizontal space I will use a flat end mill , and select the outline to cut.
  • 4. The rough cut

  • I use the 3D adaptive clearing to remove large amounts of materials.
  • Go to 3D tab > adaptive clearing.
  • Select flat end mill to clear the excess material.
  • To clear all the material off the pocket.
  • I select the bottom boundary then change the stepover to 4 mm.
  • fine step over to 1.87 mm
  • 5. The horizontal surface

  • Go to the 3D tab > Horizontal and selected the bull nose end mill. This will detects flat/horizontal surfaces and evens it out.
  • 6. The finishing

  • The parallel operation runs the final detailed shape.
  • Go to the 3D tab > parallel.
  • 7. The machining time, and exporting the files

  • To check the machine time
  • Right-clicked on the setup
  • Select machining time.
  • It will take 1 hour to be done.
  • To export the cam files, you need to select each process at a time.
  • Right clicked then select Post process.
  • To generates the Gerber files for the milling machine you need to modify the following:
  • Select > post configuration > all vendors >ROLAND DG.
  • Select Roland RML.
  • Program settings>select the machine type > MDX-40.
  • I used the simulation tool to see the toolpath of the machine, and also the final result of the milling:

  • The final result of the milling:
  • Molding

  • The last step is to be made in resin.
  • I use Smooth-on Dragon skin.
  • Before I must read the technical datasheet for the material
  • I must know the safety precautions and the periods of time for using.
  • The Safety datasheetis shown below:
  • Wear two vinyl gloves on each hand to avoid the material from touching the skin goggles.
  • A plastic apron to protect my clothes and extra mask.
  • I covered the working area with plastic to avoid the damage in the surface.
  • First is to measure the amount of material required.
  • I did it by filling the two sides of the wax area with water.
  • Then measure the level of water to know the level of the material required.
  • Then I dry the cup and the wax area.
  • I start to mix part A and part B as it is shown in the instruction :
  • 1. By wooden stick mix part A and part B separately in its container for 1 minute.
  • 2. I put water in the wax to measure the volume of the silicon needed then spill Part A and part B into the cup then take note of the weight.
  • 3. Zero the scale then measures the mass of the cup of water, the ratio of 1:1 part A and part B to reach the total mass.
  • 4. With wooden stick Mix part A and B together for 1 minute.
  • 5. Spill the mixture in the wax starting from the lowest point that will help to minimize the air inside it.
  • 6. Keep the wax in a covered surface area then came back to it after 24 hours.
  • 7. Clean the area.
  • After 24 hours the mold came out of the wax easily.
  • ________________________________________

    Casting

  • I use ArtResin .
  • The steps are shown in the website clearly.
  • Watch the video to know more about it
  • I use ResinTint Red color
  • The steps of adding color are shown in the website clearly.
  • The steps :

  • First is to measure the amount of material required.
  • I did it by filling the Silicon area with water.
  • Then measure the level of water to know the level of the material required.
  • Then I dry the cup and the wax area.
  • I start to mix part A and part B as it is shown in the instruction :
  • 1. By wooden stick mix part A and part B separately in its container for 1 minute.
  • 2. I put water in the wax to measure the volume of the silicon needed then spill Part A and part B into the cup then take note of the weight.
  • 3. Zero the scale then measures the mass of the cup of water, the ratio of 1:1 part A and part B to reach the total mass.
  • 4. With wooden stick Mix part A and B together for 3 minute.
  • 5. Add the color I use Red from SO-Strong™ urethane colorants.
  • 6. Tape the two sides of the mold together.
  • 7. Pour the mix into the mold slowly and steadily.
  • 8. Keep the wax in a covered surface area then came back to it after 24 hours.
  • 9. Clean the area.
  • After 24 hours the mold came out of the silicon easily, I was impressed with the design it was magnificent experience.
  • I wrapped the wax with the tape so the mix wouldn't come out
  • Finally look like this!

  • It is a magnificent experience and the heart surface showed nicely
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