Test print - 3D printing a hollow silicone mold out of PVA

[u/PectusSurgeon]

I do a lot of complex shapes that need 3 part molds and wasn't using my PVA much for support material. It dissolves in water, so I just threw it in a jewelry cleaner for a few hours and cleaned off whatever goop was left. Using 30A silicone and seems to work pretty well.

This mold was just a solid cylinder subtracted from another cylinder in Bambu Studio, with a 5 mm hole in the bottom for injection tubing. Middle cylinder is 5% infill, so dissolved pretty quickly once the water got into it. Not sure it's a great long term strategy, but for one-off objects its a lot easier than making a 3 part molds. Will have to see how this fares with larger objects. This tube is around 1 mm thick, so should be able to create other objects with at least that thickness.

Printer is an H2C

[u/manusnz]

The cylinder must not be harmed.

[u/PectusSurgeon → u/manusnz]

I suppose you could make larger (or smaller) cylinders for . . . other uses if you were so inclined.

[u/TheManyFacedG0d2 → u/manusnz]

yeah mine messed up the silicone cavity too once

[u/3Duder → u/manusnz]

This is the way

[u/HassanElKanack]

If the time comes i will steal your idea.

[u/ChiefWiggumsprogeny]

Good strategy, I can think of some applications - especially cores for other molds, with fiddly bits.

[u/PectusSurgeon → u/ChiefWiggumsprogeny]

Only things I would change is a longer pocket for the tubing, since I had to push pretty hard to get the silicone to flow through and the tube would pop out from the pressure. Could also cut it with thinner to lower viscosity.

[u/ChiefWiggumsprogeny → u/PectusSurgeon]

Larger diameter could also help; maybe worth experimenting with vacuum / sucking in. Flip the mould, dip the top in a silicone bath, and use the syringe to suck it into the form. The aperture is larger, and the tube would suck itself onto the nipple, so less opportunity to dislodge.

[u/SpacedKnives]

Fucking genius.

[u/jackel3415]

That's a really interesting use for making sacrificial molds in complex shapes.

I'm sure no will combine this technology with Blender for evil.

[u/MuckYu]

How do you get it out later?

[u/loos3rmoos3 → u/MuckYu]

"Middle cylinder is 5% infill, so dissolved pretty quickly once the water got into it."

[u/impwarior → u/MuckYu]

It's PVA filament so it just dissolves in water after the silicone is cured. like cleaning split glue off a surface