Crayon Casting

thingiverse

My boys destroy crayons to the point that they are basically unusable. I thought it would be fun to recast them. I designed this setup to do that. A few notes: 1. Crayons melt at about 125F. You will want to use a double boiler to melt them. The double boiler prevents the temperature from exceeding 212F which is about where the wax start to smoke. I used this coffee pot thing that we got at a random Christmas gift exchange and never use. But any double boiler system will work. 2. 212F is still hot for PLA and the molds can deform. So if you use PLA be careful with the temperature. If the water is boiling rapidly you're too hot. 3. You'll want a glossy PLA and you'll also want to print the molds vertically for easy release. No release agent is required. 4. I used a rubber band to hold the 2 halves together but printing 2 holders may do the trick. 5. As long as the PLA doesn't deform you don't need anything to seal the two mold pieces together. The pressure of the rubber bands was sufficient for me. 6. I recommend printing with 100% fill. 7. The print shown in the pictures was scaled to 50%. Very large crayons can have issues with uneven cooling. If I do it again I'll likely scale a little larger 60-70% of the STL native size. 8. Wax shrinks as it cools so I do recommend filling up the small funnel and allowing to cool at room temperature for a bit before putting in the freezer. These small crayons set in about 10-15 minutes you'll need longer for larger crayons.