Printing molds for resin casting

Is it possible to print a mold on a formlabs printer and then cast directly into it?

Like print negative, not positive? or the resin will stick to formlabs resin when i will try to cast into it?

that depends on what you are casting. Urethanes- for example- are infamous for how well they bond to just about anything.
Formlabs recently published a white paper on making small low run injection mold tolling using high temp resins.

Rigid molds have to be drafted to cast rigid materials… though you can cast rubber materials into rigid molds with undercuts… to a certain extent.

The thing to do is to run a test- you can simple use the old rafts from under prints and try pouring whatever you’re thinking of casting into those rafts to see if it releases… if not- then simply try again- after applying different release agents to the resin, until you find a product that works.

You can also try printing a mold in flexible resin.

And something we often do is print a SHELL and master… that fit together with a space between them into which we can inject or pour silicone rubber.

We have also printed rigid molds and internal bucks for injecting silicone in for facial appliances, or even rubber faces or heads that fit over an articulated robot armature,.

Sp, yeah- its entirely doable- just run tests first for materials compatibility.

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Thanks, Sculptingman!

A waxed based release agent should work fine for urethanes against molds and suited well for silicone to silicone molds.
I would use a semi flexible resin as a mold which would make releasing the part easier. A hard mold might be difficult to get a part out especially if there are minimal draft angles on the part.