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by bangaladore 790 days ago
Isn't the big downside to SLA prints that they have terrible structural integrity? Like worse than FDM prints?
4 comments

More the opposite than anything. The SLA parts are isotropic so you have the same properties in every direction and do not have to worry about breaking on the layer lines like in FDM. Formlabs has a couple resins which are very impact resistant or stiff etc, some similar to ABS, glass filled plastics or polypropylene

The resins are also getting cheaper too, It looks like they are using the new Black V5 which costs a third less per liter than Black V4 from their last printer.

I use both kinds very frequently so I can comment on this. The main difference is that SLA strength is more uniform and FDM strength is very directional.

And the strength of the output is highly dependent on the material for both printers. The typical resin is extremely brittle, but rather heat resistant. But you can get flexible or tough material which are both less brittle but also less rigid.

So to answer your question: not necessarily :) nylon-like SLA materials are pretty good for usable everyday items if you don't mind the slight fidelity losses (still better than FDM)

I've got some Formlabs demo prints that seem pretty good -- way better than the SLA stuff my friends and I make at home.

But I can safely assume that they're using much better machines, materials, and processes than I have access to.

SLA prints don't have the same layer shear issues as FDM prints, but you have to spend on engineering resin to match the same strength as a cheap ABS filament.