Tips to overcome the error 900 when forming a union

Dear everyone, For few yeasr now, I am importing complex geometries done under Solidworks.
Even if all my geometry is clean in SW, COMSOL fail to import it, or fail to form the union in the geometry node.
I have found different tips to overcome this, and I would like to share it. Also, it could be good that the COMSOL forum include a thread with the error code, and the associated tips.


Tips#1: import every single part from the assembly
a) under SW, in your assembly, save every single part in different files (it will keep the position of the object)
b) under comsol import separately each CAD file, step by step:
b.1) import first part
b.2) form the union
b.3) if it fails, play with the tolerance of : the imported part and the union
b.4) if its ok, import next part
Note: to low tolerance will create very very small domains do to intesrections of the imported entities (surfaces, volume, edges...)


Tips#2: If the Union fail despite every single part are imported: Use COMSOL to do Import-Export-Import
a) You imported your geometry and everything is fine before clicking form union ? then the Error 900 appear ? Try to convert the geometry in COMSOL (I don't know if it changes anything, but we never know).
b) export into a COMSOL geometry
c) recreate a new model and import the new COMSOL geometry.


For me it worked. I hope these tips will help somebody
Sylvain