STL file to Solid

[Anonymous]

I have stl file which i wish to convert to a solid in order to modify it.

The stl file mus be closed as i can 3D print from it.

The process i adopted was to convert it to a dxf file using http://www.cadforum.cz/catalog_en/stl2dwg.asp?go=convert and opened it with Autocad

I then converted the faces to surfaces and merged these to one surface using UNION.

I tried converting to solid using CONVTOSOLID which failed and then tried SURFSCULPT that gave the error "No watertight surface detected".

Presume it has a hole in it somewhere.

How do i find this and repair it?

STL file and surface file attached.

It won't allow STL files so i've sent the dxf conversion!

[TheCADnoob]

This is out side my wheel house but give this a look and see if it helps: http://download.autodesk.com/us/algor/userguides/mergedProjects/Meshing_Overview/meshing_cad_solid_m...

[leeminardi · Accepted solution]

One approach to find where the object "leaks" (is invalid) is to take smaller parts of the surface mesh and try to make a solid of it.

I used the slice command to cut the object into pieces. I then made surfaces where I sliced the object and used those flat surfaces to define bounding surfaces to define a volume when using SURFSCULPT.  The following pictures should give you a feel for the process.  If SURFSCULPT fails to make a solid from a piece and its bounding surface planes you know where to look for the hole.

I was able to make a solid of all the slice sections except for the cyan colored piece in the picture below.  YOu should inspect this portion or subdivide it further to find the problem.  Once you have all the pieces as solids you can union them together.

~Lee

[Anonymous]

Thanks for your reply. 

I think the "hole" is somewhere around the intersection of the web and the outer edge in the cyan coloured piece.

I got there by a similar process which was to perform a union on the individual surfaces a few at a time until it failed. I could then home in on the offending area.

I haven't yet found the hole but that's a time issue.

I presume the .stl file lost some of it's integrity when it was converted to a dxf file.