Puzzle Cake custom supports (soluble)

I came across the puzzle when I bought it for my father last Christmas and it's really interesting. During figuring it out, I had the idea to make a 3D model and print it. Alas, Thingiverse already had a model, thanks to @tapka.

As I have a couple of multi-material printers, I thought that to get a pristine parts I'd use soluble material so that the supported areas would be printed with good quality. The soluble material I have is BVOH, bit expensive but overall quite good material for this application. With some caveats...

First I tried Prusa Slicer 2 and using BVOH only as the support interface material. This didn't work out very well, because BVOH didn't stick to the sparse PLA support structure and the obviously print failed when the messy blob of BVOH started moving around with the printhead. Not sure if this is because the BVOH has been unused for almost a year or something, but I've noticed this before.

So it seems that small surfaces are hard for BVOH to stick to, but larger work fine. So seeing that configuring the slicer to do things properly isn't probably going to work, I went and designed my own supports that work quite flawlessly with PLA and BVOH.

These custom supports accomplish a couple of things:

• provide a good base for BVOH to stick to
• provide a 'perfect' base for the supported part as the BVOH is printed in regular model pattern, not in support mode pattern
• limit BVOH usage to only a couple of layers where it's needed. I use a single nozzle-multi extruder setups, so each material change needs a certain amount of purge which is practically waste
• sate my curiosity about proper soluble usage

OpenSCAD source: https://github.com/spegelius/3DModels/tree/master/Puzzle_Cake_remix

Print Settings

Printer:

FankenCube 4x

Rafts:

Supports:

No

Resolution:

Infill:

10%

Filament:

Verbatim BVOH

Notes:

Category: Puzzles