This is a bundle from a Heat Exchanger I am working on. I modified it for the Business Card display contest, but was too late.

I have included a picture with locations of where I recommend putting supports. In my pictures you can see I did not have supports under the main platform and it didn't bridge too well there. Adding snug supports there and under the hex nuts in the back and you should be good. I have added a 3mf file that has the painted support locations if you wish to use it.

Printed at 0.15mm Layer Height, any should work though.