Molding/Casting

3/9/18

For this project you need to use a 3D printed piece to create a mold and cast something out of that mold. I used a Thor's Hammer piece I created at the end of last unit. I didn't document the process. The first step is to create a box to house your mold. You can use a program called InkScape for this, which is only on the computers next to the Laser Cutters.

Open the program and go to Extensions in the dropdown menu. Select Render, and then click Lasercut. A screen of settings should appear.

Next you need to measure your object. I used a ruler, in INCHES, to measure my object.

Now, input the measurements into the computer. Make sure the unit is correct. Put the various measurements in the categories Width, Height, and Depth, as shown below.

Now, follow the instructions on this cardboard box, found in the Fab Lab. First, I make sure the Material Thickness is 0.15 inches.

3/12/18

Next, I select Laser Kerf from the tabs on the top of the box. I change the Kerf to 0.01.

Click Apply and move the pop up box. There should be a preview available. Highlight ALL the pieces and hit Ctrl+C (copy). Then open up Adobe Illustrator, and click new. Create a new document with the 24x18 parameters. Ctrl+V (paste) in the document, and the pieces should appear. REARRANGE THE PIECES SO YOU DON'T WASTE CARDBOARD!

Highlight all the pieces and change the Stroke to 0.001 so the laser cutter knows to cut these lines.

Print the document. Follow the instructions for cardboard on the sheets next to the computer. Speed is 60%, Power is 75%, and Frequency is 1000hz

Select Vector and Auto Focus, then change the Piece size to 24 Horizontal and 18 Vertical.

Put a piece of cardboard in the printer and close the lid. PRINT

Here are the 6 pieces of my box.

3/13/18

Use Double Sided Tape to attach the 3D Printed piece to the bottom side of the box. Put the box together around it, making sure you put tape on the inner borders to create a water tight seal.

Next you need to pour Oomoo into the box and create a mold. Grab the cylinders of Oomoo ingredients. They are a yellow and blue set of cylinders, as shown below. Set up a base on the table in case you spill anything. Put a piece of dropcloth on the table, then a piece of cardboard on top of that.

Pour the contents of one container into one cup, then the contents of the other into a SEPARATE cup. Make sure you have the SAME AMOUNT OF MATERIAL IN EACH CUP. Combine the cups and stir with a tongue depressor. The material should turn purple. Once it is completely stirred, pour the purple material into the box. Let it set overnight.

The next day, the mold should be hardened and ready to remove from the box. Rip the sides of the box off, being careful to not destroy the mold. Once all the sides are off, you should see your 3D object when you flip the mold over.

Carefully cut around the object to create an opening so you can pull your object out. CAREFULLY remove the object from the Oomoo shell, trying not to break the mold in half. Once it is removed, your mold is ready.

Now it's time to make some Hydro-Stone(similar to plaster). Grab two cups, the scale, a tongue depressor, and the Hydro-Stone powder. To make the material for molding, you need 100 parts powder and 32 parts water. To make it simple, we used 100 grams of powder and 32 grams of water. Place the cup on the scale and 0 it out. Then, fill the cup with powder until you get 100 grams of powder.

Do the same with the water, in a separate cup, until you get 32 grams of water.

Combine the powder and the water, and stir with a tongue depressor until you get a thin consistency. Pour the Hydro-Stone into your mold, and let it set overnight.

The next day I removed my piece from the mold to find that the Hydro-Stone didn't fill up the handle area due to an air bubble. I re-casted it today, shaking the mold to make sure the handle area got filled. I was able to see the air bubbles popping, so I know for sure that I was successful.

3/14/18

My casting was a success! I made a complete hammer. It has a few holes where air bubbles were trapped but it is a very solid piece.