Stainless Steel Build Platform?


#1

I’m just wondering if there is any advantage to the stainless steel build platform other than a requirement for use with biocompatible materials?

It looks like the steel is seamless and covers the entire sides like a monolith, so I’m guessing it is more durable. But is there any other reason why someone might use it if they aren’t printing with biocompatible resins, such as better adhesion, flatness, print reliability, etc?

https://formlabs.com/store/accessories/stainless-steel-build-platform/


#2

Just been looking at those myself for biocompatible resins. When we design rigs to be used in manufacturing of catheters and medical devices prototypes, bare aluminium surfaces are frowned upon as a source of contamination. In addition it looks like these new build platforms have sealed/welded seams so that the resin cannot seep into the build platform void. This has always irritated me with the present design, We have dedicated build platforms for each resin type to reduce risk of cross contamination.
Though the new price is high it will go a long way to reduce risk of contamination to the printed part.


#3

If you’re not having problems with the platform that came with your printer, you don’t need to upgrade to the all-steel version. The design of the build platform hasn’t really changed since the Form1. I never had any issues with my Form1+ or Form2 build platforms over years of use. So no, I don’t think there’s any reason to upgrade for the typical user.


#4

I’ve owned my Form 3 for less than a week, and both of my standard aluminum build platforms have delaminated, warped sides that don’t seem to want to be pushed back in. Is there any solution for this besides upgrading to the stainless steel?


#5

@ Greymatter,

I would totally agree with your thoughts, either 304 or (better still) 316 Stainless are excellent in terms of reducing cross contamination to acceptable limits with bio application resins.

Our personal preference in terms of risk reduction being 316 stainless due to its much better resistance to acids.

Recently on one of our printer designs we have been using a two part build plate with the base structure in 316 stainless and a print build surface consisting of sheet 420 grade stainless (0.8mm thick) held to the 316 base structure with N42 magnets on a 50mm centres matrix (10mm dia x 10 deep magnets) The end result is a very stable build plate that can be removed after the print and flexed to separate the print.

Even prints that you would expect to be very fragile remove easily using this method from the build plate and prints that have a large surface area in contact with the build plate are now a joy to remove (irrespective of how well the resin grips the build plate… No scrappers, no force and no damage during part removal

Surface finish of the 420 stainless build plate is vapor blast to 3um.


#6

I don’t have first hand experience with the SS build plates, but never have issues removing parts using this technique: https://www.instagram.com/p/CLCWSCoH5o8/?igshid=65flw51kj6gd


#7

I’m removing small models printed directly on the build platform and want the base to be free of blemishes, so this trick wouldn’t work for my application.

Standard resins are easy to remove after freezing the build plate.

I also noticed your build plate is polished/shiny but scratched. The ones I got new are bead blasted and so the surface area contact for resin is much higher.


#8

Build plates scratch up over time, there’s no way around that - anything printed directly on the build platform is going to pick up these nicks, dents, scratches. So regardless of the removal method, you’ll eventually get a printed base that isn’t free of blemishes unless you sand the printed part down afterwards (which is easy enough to do), or unless you polish the build plate regularly. Using side cutters like I showed doesn’t actually leave a very obvious blemish. Any blemish can be sanded off easily and doesn’t add significant labor because you often already need to sand that base for the reasons I listed above.

Also, it doesn’t matter whether the base is bead blasted or not, I’ve been doing this trick on old and new build plates for years. I also resurface my build plates every now and then. Anecdotally I find that bead blasted, smooth build plates actually release easier than ones with large scratches and dents (makes sense given that the resin flows and cures into those nooks & crannies).


#9

Hi Dxxx, Like the idea of a detachable build platform that can be flexed to promote separation of the printed part from build platform. Presumably SS420 was used for its relatively high permeability within the SS family…

We use a lot of N42 and N52 magnets in our work. They are quite brittle and friable and where possible we bury the magnets with a thin covering of resin on top or mount them on the reverse side of the working surface to reduce any risk of contamination from the nickel plating or magnets chipping. In both cases we have to increase the size of the magnet to compensate for the increase gap between magnet and magnetic object. In some extreme cases we parylene coat the magnets.


#10

You are correct - SS420 works well with a magnet. The coating of the main magnet face is worth while. We fit them into reamed holes in the platform and normally look at an H7 /h6 fit. To assemble we warm the main structure of the build plate support to 80c and put the magnets in the freezer (-19c) before assembly, It all pops together easily, but the magnets are nearly impossible to remove after assembly has gone back to room temperature using this method