Molding and Casting

I worked this assignment in an individual way.

Next I will describe the inputs used in this assignment,

1. File A Wax

Ferris File-A-Wax Blue is a softer wax formulated for excellent flexibility and strength. The blue colored wax can be carved into the finest of Sections, still retaining excellent detail. Good for rounded corners and less intricate designs. Due to the low ash content, this product is ideal for the investment casting process. Special wax to make original models of jewelry, dental sector, etc. very flexible It can be carved in very thin sections while preserving excellent detail. Perfect for rounded models and with fewer details Ideal for lost wax casting, thanks to the little residue it leaves

Physical Properties

Color: Blue

Melting point: 226th

Toughness (Prop): 52

Specific Gravity: 0.92

Ash Content: 0.003%

Flash point: 585º F

Measures: 147x93x36mm

Weight: 1 pound

2. Silicone Y805

The Ideal and Economic Silicone, for Super Resistant and Very Durable Molds. Good medium viscosity, it will allow you to apply it by brush and/or by pouring. Excellent Flexibility and Hardness (20-A) for molds that are easy to use and unmold. Extra Resistance to Tear and Tensile, ideal for Super Resistant Molds and with a very long Useful Life. Easy to Use, just add 2 to 3% of Silicone Catalyst to the Silicone, (Already Included in the Price). Stir until homogeneous, approximately 2 to 3 minutes and pour over the piece to be replicated. Medium viscosity White color Working time 10 to 20 minutes Curing Time 4 – 6 hours in Summer and 6 – 12 hours in Winter Hardness/shore 20-A Presentation Plastic Pot Net Weight 1 kg + Catalyst Dropper Bottle 30 gr Stored Life Time 1 Year Store Covered, in a Dry and Cool Place

3. Silikast Epoxy Resin

Silikast Epoxy Crystal Resin Low Viscosity Bubble Free Ultra Fast Drying 1500 ml

Silikast Epoxy Crystal Resin A + B Liquid Glass Set for 1500 ml LOW VISCOCITY

Bi-Component Crystal Epoxy Resin. (1000 ml Component A + 500 ml Component B

Gives a Glazed, Resistant, High Gloss and very Durable finish, in a Short Time

Mix ratio 2:1

ULTRA FAST DRYING

Working time: up to 10 minutes

Mixing Time: 2-3min

Curing time up to 4 to 8 hours pieces greater than 5 ctms (according to the Climate).

4. Liquid Release Agent

It is applied to silicone molds for easy and quick disassembly of your pieces and creations, it prolongs the useful life of silicone molds, a very small amount is used. Apply a spray in the mold spread with your finger and then remove the excess with paper, only a minimum amount is necessary if you apply more than necessary the pieces may remain opaque or oily. Remember after using your molds to clean or wash them with soap and water, if you leave excess release agent you can damage your molds and pieces.

In this activity a gear for a 3D printer was designed and replicated.

The gear was designed in Autocad .

Then it was exported to STL.

Next, I've imported the STL file in software Rhinoceros.

I did the configuration of stock box and Work Zero parameters.

I've chosen the Horizontal Roughing options tu mill the exterior of the gear. A flat mill of 1/8 inches was used.

A simulation was performed.

Then I've decided to mill the mold in 24mm MDF to test if it works. A CNC was used to mill.

The results was successful. Next I've tried to make the mold using machining wax.

First, the wax was adjust

Next, Calibrate X, Y and Z to start the milling process.

The results was good at this point.

The gear was completed.

I've used this banrd of silicone

I used a Silicone A and Silicone B.

I used Silikast Epoxy Resin A and B.

I used this release agent for easy removing the silicone

Next, I prepared the silicone, mixing 1 part A and 1 part B.

A little of release agent was used.

Finally, the silicone mixture was poured in to the mold

Then I waited for 24 hours to silicone become dry

Then, I removed the silicone

Next, I mixed the Epoxy resin, 2 parts A and 1 part B.

So, I poured the mixture in to the mold and wait for 4 hours.

Finally, this is the result.

Problems and solutions

In this activity I had some problems, mainly in the design, I realized that when using a very large cutter I lost quality/resolution in the part. To solve it, I used the thinnest strawberry I could to improve it.
Initially I tried to do it on MDF but didn't get good results. Then I did it in the moldable wax which improved a lot.
The first few times I tried not to use the liquid release agent, causing me problems to remove the mold. I immediately did another test where I added that element and the piece came out easily.

Takeaways Assignment

The molding process, which consists of making the negative of the piece using digital manufacturing, seemed very efficient to me, especially in the details. So I used a thin milling tool.
I tried another material like MDF, but I realized that moldable wax produces better results.
I have used the amounts of silicone and resin in proportions as indicated by the manufacturer. However, it is possible to speed up the curing process by varying these proportions.