Concrete Planter. Sides and interior part must be rotated 180º around the Y axis in order to not need supports (widest side always at the bottom).
GCode created with Slicer PE. 0.3mm layer height
For the sides: at least 5 perimetral wall layers, in order to make it strong and last many casts.
For the interior part: 30% infill. Designed with a drainage hole that acts as a plunger to tap it with a rod and a hammer in order to demould it. Also the square on the bottom is to insert a ratchet wrench and rotate it to free it (but it really didn't work, it's better to hit the drainage plunger with a rod and a hammer).
Remember to cover the mould with a good layer of vaseline, otherwise you won't be able to take it apart.
Sides and interior part took almost 18h each to print EACH, this is a big print but also I think it's worth it.
I used 4 parts concrete - 1 part water, but rule of thumb is to add water and mix it until it has a consistency similar to raw cookie dough.
Some of the clamps have started to develop cracks and break. But there is no need to use them, I've discovered that you can keep the mould together using clothes pegs. I suggest this option instead of the clamps.
The plunger end has broken due to the beating with the hammer. I recommend using a steel rod (ratchet wrench extender in my case) and not to hit it directly with a hammer. I'd recommend to increase perimetral layers to at least 4, with 5 top layers to make it stronger. Despite of being broken I think I'll be able to use it a couple of times more.
- With regular PLA these molds have lasted exactly 5 castings until they develop catastrophic cracks :D. I suggest that if you plan to last almost forever, you use PETG as printing material.
For the sides I used 5 perimetral layers of wall thickness to make it strong and durable.
Let the concrete sit for at least 2 days. Make sure the surface is hard to the touch before taking the mould apart.
I used CATIA to design this, because is the only program I know as an Industral Engineer.