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Hollow cavity for magnet


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Posted · Hollow cavity for magnet

This topic is all over the place clear back to 2012.  I just can't get it to work for me.  The usual solution being "Check Union Overlapping Volumes"  This isn't working for me.


Attached is the file.  It is a corner piece for a plastic door.  It has 2 screw holes and an internal void for a magnet.  I already printed the internal cylinder and it is perfect fit for my magnet.  The grey spot shows up in Cura but when i click slice the void doesn't exist, cura does regular infill.  Any ideas on how to get this cavity to work?  


This was made in sketchup.  I have that file if anyone wants to look at the original, just looks like I can't attach it here.


I made 2 versions, the first had the cavity for the magnet, the 2nd had a double shell around the magnet with the theory of making a thicker wall and maybe cura would work with that.  Neither version made any difference.

corner finish.stl

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    Posted · Hollow cavity for magnet

    I looked at your stl carefully.  I had to uncheck "union overlapping volumes".  I don't know why you thought that should be checked.  It needs to be unchecked.


    Then it prints as your STL shows which may not be what you want.  It prints a donut shaped void in your part where you could insert a donut shaped magnet.


    I assume instead that your magnet is a solid cylinder?


    If so then you have 2 problems with your model:

    1) You have a double inner wall instead of a single wall to transition from "plastic" to "magnet".

    2) Your normals are backwards:


    In sketchup you want all walls that face air to be white and the side of every wall that faces plastic should be gray.  In sketchup to reverse them, right click on a wall and select "reverse faces".


    Again, "gray" should face plastic (interior) and white should face air or magnet.


    And uncheck "union overlapping volumes".

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    Posted (edited) · Hollow cavity for magnet

    Thank you for your help.


    Still no luck.

    I deleted the outer shell, left the grey cylinder, all white are facing inward.   Still no luck.  You can see in the first image that the cylinder is in the picture, but from the top view it is being ignored.




    Edited by Mentor115
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    Posted · Hollow cavity for magnet



    I had generate support unchecked because there are no supports needed, however once "Make overhang printable" was unchecked it worked as it should.


    Thanks for everyone's time

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