First FLEX failure

We tried to print an accordion here using the Flex.
Software said “broken model detected”, but if you let it repair it from the software, it becomes completely full of material as shown on picture here on the left.

therefore, I decided to ignore the repair and go ahead with the original file, as on the right side, which appears to be correct. I tried to print two of them as shown below:

Result was that accordion has been anyway printed totally full with a very bad result (one has fallen down in the resin as it was too heavy)

Anyway can anybody suggest how to solve this and what has happened?

I would be inclined to put your file through Netfabb and find out why the model is broken, fixing it before attempting a print. Best guess is you have one or more holes in the shell.

Look through the layers using the slider on the right of the window to see if you have any mesh errors. Preform uses Netfabb to repair models so you may get the same result using their cloud service.

You should also consider orienting your models differently. The auto-orient feature in Preform usually does a very good job, especially with ‘simple’ geometries like your accordion. Putting the model at an angle (like the orient feature should do) will help reduce a) overall surface area (like the ‘shelf’ I can see in the first image) and b) sudden changes in surface area that form unsupported overhangs. Hope this helps!

There is a good chance the model has some flipped normal creating holes in the geometry. Not sure what program you are using but if you have any “unify normal” option on it or can manipulate the orientation that should solve it.

You might be able to view and possibly fix in Meshmixer though it tends to fail on me quite a bit with large poly models.

Just because it looks right in your CAD program doesn’t mean it is right. The STL tells PreForm what your model looks like. If PreForm says there are errors in the STL that means it is telling you it can’t figure out what your model looks like. If you tell it to repair the errors and the model is “corrupted” by the repair, there is something fundamentally wrong with your geometry. Ignoring the error and printing anyway is likely to result in failure. If PreForm can’t repair it satisfactorily, try other tools like NetFabb or MeshMixer. If they can’t fix it, you have to go back to your original CAD drawing and figure out what you did wrong.

Thanks to everybody.
I agree, something went wrong in the conversion from IGS to STL, and file is definitely corrupted with some inverted normals.
What I don’t understand now is that I see on the right side of build platform the accordion “empty”, and when printed it is completely full of resin.
Even if file is corrupted, I should get printed at least what I see on the software, not something different.
A great improvement from Formlabs whould be to be able to load IGS and STP file directly without the need of a conversion. Anybody from Formlabs thinks this may be possible in the near future?

No, that’s not correct. What you see on the screen is generated by video HW that could care less about whether or not polys are connected, whether there are holes in the object or nonmanifold eges, or if there are degenerate polys or stray vertices. The graphics HW will do its best to draw what its told to draw and could easily end up with something that looks “right”. Doesn’t mean it’ll print. The printing process requires that the geometry be right, not that it just look right.

1 Like

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.