With the release of the Build Platform 2 with Quick Release, Form 3L owners are hung out to dry until a Large version is released. Has anyone ever considered embedding magnets in the build platform and adding a thin steel work surface to actually print to? I don’t see why this wouldn’t work, the only possible change you may need to make is to machine off the thickness of the steel from the platform to maintain consistent thickness.
Thoughts? I’m thinking of trying it.
Actually many other resin 3D printers are using a detachable thin steel plate with magnets (for example photocentric HR2), it’s not something innovative for the 3D industry. It’s more like Formlabs are re-inventing the wheel here so as to stay in par with what competition is already offering…
Ya, that may work. I’m not sure about the form 3L platforms, but the regular 3’s are just extruded aluminum with plastic caps on the side. Put it in a vacuum chamber to pop them off. I live at altitude, so the atmospheric pressure does that for me whenever I order them. You could try just epoxying a few large magnets in the cavity against the working face.
Regarding machining the surface, I don’t see why not. You could probably deck it down 1-2mm and still have plenty of meat to work with. The build platforms don’t have to be deadnuts flat, the $250 stainless steel ones I just bought certainly aren’t. I can put a flat reference across the surface and easily slide a 0.005" shim in there. It’s a concave deflection btw. For a sheet, I would go with a 301 stainless spring steel. Spring steel so it can handle the flex cycles and not distort. Stainless to resist any interaction with your resins. This wouldn’t be a bad place to start: McMaster part: 2416K129. I think this material is magnetic - definitely try it before committing to modifying your build plate. McMaster says the material is cold worked, which typically means the magnetic properties come back - but not all stainless steels are.
For reference, I just measured my Prusa flex plate and it’s 0.05" thick. It feels pretty chonky, so you could probably err a little bit thinner - I think the Prusa plate is coated with something anyway. I’d sandblast the front or hit it with a sander to rough it up to promote adhesion.
Also, the build platform thickness on the Form 3 is 35mm, I’d imagine it’s the same on the Form 3L. Just machine down whatever thickness of the spring plate is and, in theory, you should be golden.
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Keep in mind that you will need to use strong enough magnets to not give out from the heaviest item printable on top of the suction forces generated for each layer.
My suggestion would be to have some sort of securing mechanism just in case.
There is a lot of pull force on some prints. What I have found and do is build my model with a grid of 2 mm blocks on the bottom spaced at 2 mm and then the whole model will just pop off when cutting the first corner block with cutters. Of course you then have to sand off those support blocks but it’s quick work with a power sanding disk. I make mostly mechanical prints and lay them out so the flat surface is printed first. My many prints do this and always pops right off with that first cut.