building platform

[maxman]

Hey,

i think there is not suitable topic in this community, so i will start this now

I've read a lot about different kinds of building platforms, but until now there are so many different opinions......

So maybe we can start a summary of different building platform types with own experience.

What do you think?

[johnrpm]

I agree, I intend trying different material with different surface finishes, until
I find the right one, it may be that some geometries/resins require different platforms.

[258cj7]

I'm using a piece of 1/4" aluminum plate that I scuffed slightly with some fine sandpaper. So far it has worked ok. I did have one failure where I had a large base that started to separate. I don't know if it was because of the resin shrinking or if I needed to expose it more to get a good stick. The prints with smaller bases (1-2 sq inch) all stick just fine. I can remove them by slipping a single edge razor blade under one edge and they pop right off.

[sitzme]

I am currently using 1/2" thick alum plate as I had some around. The build surface gets scored (slashed) with a utility knife at multiple angles at about 3/8" spacing. It is then sanded briefly with 46 grit to knock off any real high spots and further roughen the surface. On larger parts shrinkage still seems to cause some prints to release from the plate. I am considering adding a matrix of 1/8" through holes to add to the mechanical bond but it is a little too soon for that. This build plate is 10.5" square and suspended by 3 threaded rods.

[258cj7]

As to the shrinkage causing larger parts to release form the build plate:
A sugestion I picked up from one of the other forums was instead of having one monolithic base that can shrink and pop off, try breaking it up into smaller islands and raise the part on supports so the stress from shrinking isn't as severe. I haven't tried it yet but it seems to make sense.

[sitzme]

A series of pads with supports is something that I have considered and will probably try. One of the types of object that I've been playing with resembles a drink coaster and I wrote a chunk of code to build them by printing 2-3 images repeatedly. One for the base layers, and another for the image layers. This makes it a little harder to work with pads and supports but can be done. There is no model to tilt so it can be pealing a very large area during the prints.

There is a lot more to UV DLP printing that it originally appeared. It is still a fun learning experience.

Maybe the build platform should have a series of flexible fingers or posts that point down with small gaps in between. This would allow some flex without designing it into the print. How about using small tiles set it a matrix of silicone and backed by aluminum? The build would be easy enough. Lay the tiles on a sheet of glass, build a dam around them, add three hard points to support the aluminum, pour it, place the aluminum and come back in a day. The tiles could be aluminum but I am also curious about ceramic. Has anyone tried a ceramic build plate?