Open studio and have a play with it . There does appear to be a certain operation it doesnt like though , happy testing
Success! (Eventually - spent 3 solid mornings on this, almost gave up as sick of the sight of it). Here’s what I did.
Imported the .3mf into Fusion, which makes it a mesh, so converted to bodies. Added a backing sheet slightly thicker than the letters & combined all the letters with it using the cut function & retaining the tools. This worked for most letters, but not for others due to near-coincident geometry.
For these, I extruded sets of the top surfaces upwards, creating new bodies, then extruding the bottom surface of the new body back down to the original depth, then subtracting that from the backing plate. It sometimes took a few attempts to isolate & ignore the bits that made it fail. Then delete both the original letters & the new bodies created above them.
Finally, create a space in the box the same size as the backing sheet & print. Got them slightly misaligned, but it will do for me.
I will need a better process if I need to do similar in future.
