So a friend of mine is making a cosplay outfit for Aladdin from the anime Magi and needed the jewel that he has on his forehead. Jewels of a specific size and shape are hard to find, so she came to me to see if I could do it.
My first step was to model the jewel in Sketchup. To make the elliptical jewel I simply made a sphere and then scaled it to the correct dimensions for an oval. I started out at 3 inches long and 1.5 inches wide, however, that was too big. I scaled it down to 2.5 inches long and 1.25 inches wide. You can find my sketchup file here: Aladdin’s Jewel
Once I had the model I then sent it off to my 3D printer. Here you can see the first large version then the smaller version.
With the prototype printed out, I went ahead and sanded it and then wiped it down with Acetone to help melt and smooth out the ABS plastic.
Next I sprayed it with some Primer Filler and then sanded that down to fill in some of the gaps and to help me better see where the bigger gaps were.
I then proceeded to cover the jewel with bondo putty.
Then I sanded it down nice and smooth and wiped it down with a wet paper towel to remove the dust.
I then created a simple mold box out of foam board and hot glued it down.
I then poured in some Smooth-On Oomoo 25. After 2 hours I had a nice perfectly smooth mold.
I then measured with some water how much Tap Plastics Clear Cast Resin I would need to use. It came out to about 0.5 oz. And like always, I write this amount on the mold with a permanent marker. I also put in about 8 drops of red dye as I wanted it to be a nice deep red.
And after about 6 hours of curing, I popped out the jewel and we have a nice perfect red transparent jewel! It is still a bit sticky and normally takes a couple more days to fully cure. If it is still sticky after a couple of days, a simple acetone dip will help remove the access resin.