1

I would like to get my product printed in reverse for use as a mold.

Can this be done? Are there flexible materials that can be used so the item releases from the mold easily?

Thank you.

2

flexible filaments aren’t easy to work with. the extruder sometimes can’t pull it right, or it doesn’t adhere to the layers below it, etc.

also, even if you created the mold, you’d have 2 capital problems:

1 - It would NOT accept high temperature materials inside (plastics have low melting point)

2 - the layers would be apparent on the final product after the cast.

To work with molds, it’s recommended to use some special resins in SLA printers: their layer height is way smaller and some resins aren’t affected so much by temperature, being used even as mold for jewelry

3

Hi cdmerry,

I have tried the same thing with limited success. I don’t know what material you’re using but I can say that from a SLA resin trial an error, reversed model (negatives) do not hold up to being used as molds. I tried several attempts to make print negatives in from clear, while the prints worked fine, the plastic was too porous and grabbed the casting resin like no ones business. I wondered about the flexible material too. I was reluctant to try the flexible resin print as a negative because I’m making an assumption it too would be too porous, the difference is the silicone doesn’t stick to plastic. Hope that helps?

4

It can be done. I make “hard” molds but printing one with much detail in a flexible could be tricky.

5

Thanks to all for the information.

6

I (mostly) agree with others. I’ve tried making molds with SLA resin (PLA and ABS will melt or dissolve). It CAN work but you have to coat the inside of the mold and depending on what you’re casting you may need to break the mold to get it out. I have not tried Formlabs new flexible resin because it would be a pretty expensive test. Could be interesting.

However, I’ve had great success in making quick silicone molds from SLA positives. You can see an image of one on my hub page. I used a 3D scan and added a simple cylinder to make a positive for a chocolate mold. It’s an extra step and cost from directly printing a mold but it’s not difficult and the silicone will last for many many casts.