Wrong dimensions in my model

Discussion in 'Software and Applications' started by tefa, Apr 27, 2012.

  1. tefa
    tefa New Member
    I made a model using Inventor, with the dimensions I wanted it to be. In the archive containing the model I specified "inch" for the units, and converted it to stl format in order to it could be accepted and uploaded with any problems. Then I uploaded the model to shapeways and I had to choose the units of the model, so I indicated "inch", the units I had been working with.
    My problem is that once the model has been correctly uploaded to "my models" the dimensions that are indicated there are not the same that the model really has, they are completly different.
    This is the first time I upload a model to Shapeways, so I would thank you a lot to help me, because I don't know if I'm doing something wrong.
  2. stonysmith
    stonysmith Well-Known Member Moderator
    I wonder if Inventor is doing kind of conversion on output.

    May I suggest: in Inventor, create just a simple cube that is 1 inch on each side. Upload that to your shop and see what it comes up with. If the dimensions are still wrong, then post the STL here in the forum so that others can take a look at it.
  3. tefa
    tefa New Member
    Here you have the 1 inch cube with the stl extension :)

    Attached Files:

  4. tefa
    tefa New Member
    And also the one created with Inventor, before converting it to stl.

    Attached Files:

  5. tefa
    tefa New Member
    When I uploaded the 1 inch cube, wich I'm sure it was made as 1 inch cube, I observed that in the dimensions were indicated the following: "in: 2.5 w x 2.5 d x 2.5 h" and "cm: 6.46 w x 6.46 d x 6.46 h"
    We know 1 inch is 2.5 cm, but there it indicates that it is a 2.5 inch cube, and that is what I can't understand...
    If I don't know the reason why this happens, the only solution I find is to make my model in Inventor using a scale of -2.5, or maby trying to use another cad program and see if then this doesn't happen.
  6. stonysmith
    stonysmith Well-Known Member Moderator
    Again, I know nothing about Inventor, but.. it's failry obvious that it is writing the file in Centimeter units instead of inches or millimeters.

    There's a very simple fix for this.. load the STL into Netfabb (free) and use the SCALE operation to multiply the size by 10, then upload it to Shapeways, picking "millimeters" for the upload units.

    It wouldn't hurt to toss a suggestion onto http://feedback.shapeways.com for them to have centimeters as an upload option.
    Last edited: Apr 28, 2012
  7. tefa
    tefa New Member
    Thanks for your answer.
    In fact, it seems inventor makes some conversion and the .stl file is not the same dimensions as the one I made. It seems like the model has been applied a 0.1 factor scale, at least this is what has happend with my model.
    So I have used netfabb, as you suggested to me, scaled the stl file (with a 10 factor), and now the model I uploaded to shapeways has the correct dimensions.