Bonsai pot mould for concrete/cement

thingiverse

This is a basic oval bonsai pot mould for casting cement. It is designed to be as big as possible for a 30x30cm print bed. Print the sides 45° rotated on the Z axis. It also prints well at 70% scale (see my last two photos). Print two of the sides, they are the same. Liberally oil/grease/vaseline the 3 parts before using pegs or bulldog clips to hold the mould together then cast with runny cement. I recommend demoulding the sides a few hours before demoulding the middle so the sides have time to harden. The middle comes out better than the other pot moulds I've tried on thingiverse, probably because the mould is shallow. I like to use plasterboard mesh tape over the large drainage holes to keep the soil in the pots. Infill at 20% worked well for me with no supports. The middle part prints well on the top surface but might string a bit on the underside without supports.