Ashtray Using 3d Printed Mold

Hi All,

In this instructable, I will share how to make a mold for an ashtray using 3d Printing. The same logic can be used to make other molds for planters, miniature etc

• 3d printer
• Cement
• Sunboard
• Superglue
• Sandpaper
• Styrofoam sheet
• Thick cardboard
• paper tape
• Bowl to mix cement

• Before we make our mold, we need to plan
• I used tinkercad to design the model
• Thickness for walls or steps should be 8mm or higher
• no overhangs
• Keep it simple
• We need the negative of this design
• Covert the design into the hole and cut it into a square for which the length and breadth are the same but the height is 1mm taller
• The result is as shown. We have a (inverted) base

• To use regular PLA as mold, we need to keep the outer walls as thin as possible (2)
• We have a base, so we have to skip the top layer
• No Infill
• No Supports
• Layer ht 0.2mm

• Since we did not print the top layer, we need to fill the gaps with styrofoam sheets
• I also used cardboard pieces for the steps
• Use paper tape to keep walls from bending
• Use sun board and make a base, stick the 3d-printed model on it
• Now add walls.
• I sed super glue to stick them

• In a bowl, take cement and water in a ratio of 2:1
• Mix well to make a paste
• Fill the mold with the cement paste
• shake the mold to release any air bubbles
• Let this set for 10 hrs

• PLA becomes brittle when in contact with water and cement, we can easily peel
• First, remove the base, then the walls, as shown
• Using a cutter make holes and pull out the 3d-printed parts
• It takes time but, you will be able to remove all the printed pla

• This step has to be immediately after demolding
• Using a blade, trim the edges, smooth out the walls and base
• Wash with water
• Now dip the casted cement (ashtray) in water for 3 days to cure cement

• After 3 days, remove the ashtray and set it aside to dry for 2 days
• After 2 days inspect for cracks, if cracks, use super glue to fill it
• You can leave it as is or paint it

Please share our suggestions or feedback...