Save as Mesh generates hundreds of errors

[wrewing001]

I'm a newbie looking for any help I can get.

For 3D printing, I use Save as Mesh to generate .stl files.  I import them into Lychee Slicer which detects errors.  Happily sometimes, Lychee's repair function eliminates all of the problems.  About half of the .stl files I make with Fusion contain errors that Lychee detects.

Within Blender software, I use a 3D Print add on to analyze and repair problems.  These can include holes in the mesh, squares that are not planar, severe angles and other obstacles to slicing a mesh into something a 3D printer can handle.

Interestingly, I have two very similar components in Fusion 360: one needs no repair and the other cannot be completely repaired by Lychee or Blender. Obviously, learning what is critically different about the two components could be very revealing.  There are no warnings or errors when I do a Compute All.

Some repairs done with Blender actually removed a visually obvious, significant amount of material, making it unprintable.

What options to improve things do we have in Fusion 360? 

In Save as Mesh, there is a High/Medium/Low level of "refinement" which does not seem to help.  When I select Preview Mesh, nothing happens.   Text labels in Save as Mesh are cut off. 

Is there documentation that explains the "Refinement Options" in Save as Mesh?

Would any Inspection features in Fusion be helpful here?

Can anyone recommend a mesh analysis/repair tool they like?

[laughingcreek · Accepted solution]

could be something inherently wrong with the geometry of your model.  if you export a .f3d file and attach someone can look at it.

[wrewing001]

Attached is a .f3d file you suggested I submit.  Thanks for the help!

[TrippyLighting]

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@wrewing001 wrote:

... There are no warnings or errors when I do a Compute All...

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While I don't think this has anything to do with the printability problem, there are several failed mirror operations in your timeline. Those are present before and after running a Compute All:

[TrippyLighting · Accepted solution]

Are you using a resin printer, or how do you want to print these tiny structures ?

[wrewing001]

I am using a resin printer.  Layer thickness and LCD pixel size are both 50 microns.  The rivet and bracing detail look amazing.  This is an N scale (1:160) model of a 1000 foot long (75 inches in N scale) railroad bridge.

After looking at some of the advice you and others were giving out, I set about to make sure that every sketch I had was fully constrained.  Happily, for every component that I achieved this, there are no more mesh problems.

Call it reason #47 that fully constrained sketches are worth the effort.  Please spend no more time on this.  If I ever get a mesh problem on a component that is fully constrained, I will resubmit.

Thanks to all the crew that helped.