Structural Integrity

Discussion in 'Customer Service' started by alphalang, Nov 14, 2017.

  1. alphalang
    alphalang Member
    Hi guys,

    thanks for manually checking my 3d printing order. Your manual effort on every model is well appreciated.

    My current model has passed all manual checks except "Structural Integrity".
    Blue Polished - Strong and flexible
    Min. Wall Thickness: 0.7mm
    Min. Wire Thickness: 0.9 mm

    The minimum diameter of the model in the screenshot is actually 0.9 mm and technically should fulfill the restrictions from above. However, this screenshot was provided by the team. I am not sure, what t=1.38mm describes here. Could you please elaborate on this?


    The mentioned area is an actual pull linkage between two blocks (which can be broken when the model arrives) - is it safe to print this model as "Print Anyway" - keeping in mind that you might end up searching for 10-20 disconnected pieces?

    Would the "Structural Integrity" check for unpolished objects pass as the model would not have to withstand the ceramic pellets process?

    Thank you very much in advance.

    Attached Files:

  2. mkroeker
    mkroeker Well-Known Member
    Best just reply to the rejection email to get a response from shapeways - that way they will at least know which model file this is and maybe even get the person who spotted the problem to comment. Occasionally it may happen that they pick the wrong reference point in their version of netfabb studio when they want to highlight the problematic value just for the email. Here I suspect that it was actually the 0.9 diameter of the attachment point that s/he intended to mark - with the paddle shapes attached this may not be sufficient to survive the trip in the tumbler. But my guess may be wrong of course - only shapeways can actually answer that.
    alphalang likes this.
  3. MrNibbles
    MrNibbles Well-Known Member
    Wasn’t there a change at some point that increased sprue diameter to 2mm? I’m not even sure if it was clearly documented but it caused a lot of heads to explode a year or two ago here on the forum.
    alphalang likes this.
  4. mkroeker
    mkroeker Well-Known Member
    Good point - this rule was added as the last paragraph in the section covering wire thickness. Bet it makes handling easier for them, but makes the sprue the strongest part of some models. Alternate arrangements with some sort of cage around them are likely to be more expensive I guess. "Print it anyway" should work if you need this only for yourself (the option is only available on own models ).
    alphalang likes this.
  5. alphalang
    alphalang Member
    Thank you very much for the quick reply so far mkroeker and MrNibbles.
    I have followed your advice and reached out to the customer support to get clarity on this. As soon I hear feedback, I will update this forum thread in regards to the best solution.

    Kind Regards.
  6. UniverseBecoming
    UniverseBecoming Well-Known Member
    T in Netfabb stands for wall thickness. The Shapeways analyst is saying that the thickness at that point is 1.38 mm, which is below 2 mm minimum for sprues that connect parts together. Structural integrity means that it may fall apart during postprocessing.

    It's strange that Shapeways doesn't have a canned response that is more verbose concerning what the issue is when making a rejection notice. They are evolving SLOWWWWWLYYYYY though, so eventually, they'll start doing that in order to cut back on confusion.
  7. MrNibbles
    MrNibbles Well-Known Member
  8. UniverseBecoming
    UniverseBecoming Well-Known Member
    HAHA! Good one! :D
  9. jimmyadvice
    jimmyadvice Shapeways Employee CS Team
    Hi @alphalang

    Thanks for reaching out about this issue. I see that you have reached out to us directly via email, which is always the best route to get any issues or questions answered.

    @UniverseBecoming is correct - this is related to the sprue connection, not wall thickness. The program we use to flag the models only gives us limited "flags" to note problem areas. Apologies for any confusion!
  10. alphalang
    alphalang Member
    Hi guys,


    thanks a lot for the great help in the forum and from direct customer service.

    The model was printed as "Print it Anyway" and was rated with 100% printability. The sprues in general were printed very well. The complete model structure (about 3x6 such blocks) broke once in the middle, but this was absolutely fine for me, as I intended to break it apart anyway.


    So overall, if you intend to just connect two small model with such a sprue, I can recommend it - however, do not use such thin connection for models you want to keep stable.

    Thanks a lot Shapeways-Team, well done!

    Kind Regards,

    Attached Files:

    jimmyadvice likes this.
  11. jimmyadvice
    jimmyadvice Shapeways Employee CS Team
    Thanks for the feedback @alphalang - glad we could help!