Salah's Week 6

Assignment

Group Assignment:
- Review the safety data sheets for each of your molding and casting materials
- Make and compare test casts with each of them
Individual Assignment:
- Design a 3D mould 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.

Evaluation Standards

Link to the group assignment page
Review the safety data sheets for each of my molding and casting materials, then make and
compare test casts with each of them
Document how I designed my 3D mould and created my rough and finish toolpaths for
machining, including machine settings
Show how I made my mould and cast the parts
Include my design files and ‘hero shot’ of the mould and the final object

Output Preview

Fusion360 MODELA Player 4

Group Assignment

In this assignment we are going to review the datasheets for safety and mixing instructions of molding and casting materials. Here is the materials we have at our lab. Silicon rubber and epoxy.

Safty Instruction

The work area must be well ventilated.
Protective gloves and safety glasses must be used
If anything got spilled on hands, it must be washed very well
If it reached the eyes, it must be immediately washed, and a doctor must be consulted
It's a bad idea to smoke or eat while handling these materials
The package should be stored in a temperature less than 35°C

Mixing Instruction

The mixing ratio for the silicon rubber is 1:10 meanwhile the mixing ratio for the epoxy is 1:3.

Machining Tutourial

After that we had a machining tutorial to show the students how to setup the machine and how to use modella player 4 to generate the toolpath.

Mold Design

I've never done molding before. I decided to make a design where I can try the concept without worrying too much about the design.
I descided to make thor hammer

I opend Fusion and begain with Designind

Then I sliced the body in half in order to build the mold around it.

I built the mold by extruding a bottom, four walls, and two registration pins. It made a mistake where I made the walls equal the same height of the top point in the design. The walls should go higher that the design in order to have the poured material covering each point in the design without getting spilled over the edges.

I finally combined the two molds in a single body in order to have it manufactured in single process.

Mold Fabrication

To machine the mold on the Machinable Wax, we are gonna use the Modela Player CAM software. First, we need to import the STL file that we exported from Fusion360 in the previous step. And, From the “Model” button we gonna check the model dimensions if anything went wrong or if we need to scale the model up or down. Then, we're gonna set the orientation of the model to the top surface. Lastly, we need to set the origin point of the model, I selected it at the bottom left corner.

It’s very important to select the right material that you're gonna machine on the modela. In my case, I’m using a machinable wax block as I mentioned before.

After that, we need to set some other parameters, click on the model form button. Set the margin to “manual”, and set it’s value to 1.5mm is enough to make the casting process easier later.

A very important part here is to set the depth of the cutting process correctly according to the depth of the model that we designed on Fusion360 before. In my case, the cutting depth of my model is 11.5mm in the first half of the model. The depth between the top wall and the hammer base is 7.5mm but we need to put the female pins in our consideration too, the depth of the pins is 4mm(8mm/2). So 7.5mm+4mm = 11.5mm which is the total depth of the mold.

In the slope menu, I set the top slope to 10 degrees that make the edges more smooth with no sharp edges. That makes the resin pouring later in the casting process easier and also to remove the mold from the wax easily. The cutting area indicates the full area of the model that will get machined. If everything is fine press “Ok” and proceed to the next steps.

I used a 1/8'' ball end-mill for roughing and 3/32'' ball end-mill for finishing.

The next step is to define the process to do. It starts by defining the roughing process.

I also defined the finishing process; where the model details should appear in their final finish.

It’s very important to select the right material that you're gonna machine on the modela. In my case, I’m using a machinable wax block as I mentioned before.