Segments of a wheel rim are disappearing - what to do?

Discussion in 'Technologies and Hardware' started by Pico, Jun 14, 2013.

  1. Pico
    Pico New Member
    I've uploaded this 7 times in the past several days and have yet to get it right. Every time I upload it I have random segments of the rim that disappear. I have run this through Netfabb each time and the file is whole but when it gets to Shapeways there are missing parts. This is a relatively complex part for me so I am lost about how to fix it. Any help would be appreciated. Thanks, Pico
     

    Attached Files:

  2. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    Can you share the file?
     
  3. Pico
    Pico New Member
    Here it is. Pico
     

    Attached Files:

  4. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    It looks like the sections that are missing, are missing because you have internal faces. I'm seeing lots of red in netfabb and duplicate faces inside the rim.
     
  5. Pico
    Pico New Member
    How do I eliminate the duplicate or internal faces? Thanks, Pico
     
  6. Pico
    Pico New Member
    I am going to download a plugin for Sketchup called cleanup which should eliminate the duplicate faces. Pico
     
  7. Pico
    Pico New Member
    Still having problems with this - I wasn't able to downloaded the plugins that I wanted so reworked the mesh but still having problems. Here's a pic of the item in Netfabb. How do I correct the yellow lines? Almost all of that rim in yellow disappears when I put it in Shapeways. Thanks, PElgin
     

    Attached Files:

  8. stonysmith
    stonysmith Well-Known Member Moderator
    Sorry for the confusion here.. When you look at it in Netfabb, the yellow lines are actually HOLES - it is telling you that you are MISSING a face at that spot (not that you have an extra one)

    If you use the Netfabb option to "Close all Holes", it will attempt to close those holes.

    The other trouble is that you have many, many segments of the circles turned inside out.. When in Netfabb repair mode, everything that is inside-out is a red color. You can attempt to use the option "Repair Flipped Triangles", but I didn't have a lot of luck with it on your file. It is these red segments that are being removed when you upload it. The red coloring says that the object has a negative volume.

    I would go back to Sketchup and try re-exporting. The model is being exported as hundreds of separate peices, and it really would be better if it was a single peice (single shell). Did you happen to use the "ungroup" option in Sketchup? (you shouldn't have)

    I seem to remember something in another forum posting about some setting in Sketchup that affects whether the peices are exported as a single peice or not, but I can't (yet) find that posting.
     
  9. Pico
    Pico New Member
    Thanks for your informative comments; I'll work on this today. Pico
     
  10. JACANT
    JACANT Well-Known Member
    If you can share the original Skp file. On the forum, by PM, or my email below. I will have a look at it for you.
     
  11. Pico
    Pico New Member
    I've worked on reversing faces, there are a lot of bolt heads that are going to be very time consuming. I still haven't figured on what to do with the yellow lines. Thanks, Pico
     

    Attached Files:

  12. Pico
    Pico New Member
    . I'm stumbling around about this quite a bit and appeared to have stumbled onto correct way to fix this and that is by grouping it. The errors are way down and when put through Netfabb and uploaded to Shapeways seems to have not lost any segmants. Using a plugin called Solidsolver on SU may have helped but I've tried a lot of different things and am uncertain which have helped. Pico
     
  13. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    Good thing I called in someone more experienced with Netfabb!
     
  14. JACANT
    JACANT Well-Known Member
    To reverse the faces of the bolt heads. Pick the top face of a bolt - right click - Select > All Connected. Right click again, while over the bolt head - Reverse Faces. That's the easy part.
    The main problem with the model is you have faces on top of faces. That is why you are getting faces in the wrong direction. Which confuses the software into not knowing what is inside and what is out. Every time you draw a line on a face an extra face may be created which will be on top of the original face. You need to be very careful when drawing lines to make faces, that they are joined at the correct 'end point ' for example. If the face does not appear automatically when you close a shape, do not just draw another line. Find out why the face was not created, by checking the end points of the lines.
    You need to delete all of the extra lines you do not want. If you end up deleting the wrong line a face will disappear, just redraw that line. Some of the lines will be invisible. Go to - View - Hidden Geometry to show them.
    Another thing you need to do when drawing is once you have drawn a shape, say a bolt head, select it and use the command, Right click - Intersect Faces - with Model or Selection , depending what you are doing. Then all of the extra lines and faces that are not needed can be deleted.
    What you are really aiming for is one outside shell with no internal walls or faces. Be methodical as you draw. It may take longer but you will have less problems if you do it as you go along.
     
  15. Pico
    Pico New Member
    Thanks for the in depth reply. Much to chew on there. That will be tomorrow's job. Pico
     
  16. JACANT
    JACANT Well-Known Member
    I may have inadvertently deleted some of the faces. I don't know.
    File sent by PM.
    Millerfront.png
     
    Last edited: Jun 22, 2013
  17. Pico
    Pico New Member
    Thanks very much for the help. I have printed out your comments and taped them to the wall over my monitor to keep me straight. Pico
     
  18. JACANT
    JACANT Well-Known Member
  19. Pico
    Pico New Member
    Excellent article! Thanks. I've bookmarked it. Pico