13. Molding and Casting

This week's assignment consisted of making a mold, so I thought about making a mold to make a cat-shaped candle.

For more information about the different ways to make a mold, you can check the GROUP PAGE. To make my mold I used a wax block and machined it on the router.

The first thing I did was download a cat model from Cults and open it in SolidWorks as a solid.

1. SolidWorks

The first thing I did was cut my cat diagonally and check with the mold tool for the undercuts it might have.

Then I made a box slightly larger than the size of my cat model, but it is important to uncheck the merge result option.

In Insert > Features > Combine we select the Subtract option.

In Main Body we select the box and in Bodies To Combine we select the shape of our model.

Once we have the negative of our mold and it looks like this:

We are going to repeat the same steps to get the positive of our mold so it looks like this, and we save it as an STL.

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2. VCarve

We open VCarve and set the units of our material.

Then go to Import > Import 3D components.

With the following options we have to make sure our model is centered on our material.

To make our mold we use two toolpaths:

Roughing
Finishing.

1.- Roughing, in tool data we select the tool we have, which in my case is a 1/4 EndMill, click accept.

Roughing simulation

2.- Finishing, in tool data we select the tool we have, which in my case is a 1/4 ball nose.

Finish simulation

This is how the simulation of my mold looked, I saved my files for the "ASIA ROBOTICS" router.

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3. Router

To see how the router works you can check my WEEK7.

To place our piece of wax we have to place a board that has nuts and we place the board with the Asia clamps, then we place the wax block and secure it with the clamps located next to the router and fasten them with screws.

Then we place the roughing tool and once it has finished we place the finishing tool.

4. Silicon

To make our counter mold we use the mold we made on the router and make a silicone mixture, the silicone I used was the following:

This silicone should be mixed in a ratio of 100% of chemical A and 10% of chemical B, according to the silicone datasheet; furthermore, according to the datasheet, we can know that this silicone dries in 40 minutes. I made the mixture and then placed it in the vacuum machine where the steps are as follows: