Millimeter dimensions not saving to model

Discussion in 'Design and Modeling' started by Jpreskitt, Jan 16, 2012.

  1. Jpreskitt
    Jpreskitt New Member
    I continuously upload my .obj model and select mm from the dropdown, but when I go to "my models" only 'IN' and 'CM' are available at the bottom of the 3D model window. This of course adds thousands of dollars to my model for purchase and I don't need my model at those dimensions (in or cm) I need them in mm.

    Attached Files:

  2. stop4stuff
    stop4stuff Well-Known Member
    Hi John,

    Welcome to Shapeways! :)

    I don't use Blender, however if I understand correctly Blender has no native units of measurement (mm, cm, in etc). One Blender unit can be equal to 1mm or 1 meter, so if your model is 457.2 Blender units wide and you upload in mm, your model will be 457.2mm (45.72cm) wide and similarly 457.2 inches if you choose inches.

    If you want your model to be 45.72mm wide (4.572cm) simply scale the whole thing down to a 1/10 of it's size in Blender before upload.

    cm & in on the model page correspond accordingly, 1in = 2.54cm = 25.4mm, they do nothing to change the size of your model.

  3. Jpreskitt
    Jpreskitt New Member
    I don't use Blender. I use Cinema 4D. I modeled the part in mm and uploaded it correctly and actually choose mm from the dropdown during upload. After, in "my models" there is only two options "in" and "cm". Are you seeing the same thing? Is this a glitch with the Shapeways site? I don't feel like converting as it seems like Shapeways has this ability.
    Where is the mm option in "my models" product details page?
  4. stop4stuff
    stop4stuff Well-Known Member
    Sorry, my bad :rolleyes:

    You don't need mm if you have cm, just multiply by ten to get the mm from cm... cm or in on your model page does not affect the model, they just show the size in metric or imperial measurements.

    What size is your model and what size were you expecting it to be?
  5. skgoa
    skgoa New Member
    Uhm, for almost all file types Shapeways ignores what you chose in the dropdown menu. I had to learn that the hard way, too.
  6. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    Shapeways doesn't ignore units. Some file types default to a unit, some software exports at a unit besides your selected unit. But what I think the problem is, when your file is uploaded you can only view the dimensions in inches and cm. This doesn't change the size of your file. Just make sure what is listed for the cm dimension is 10% of what you mm dimension was. That switch is just to view the dimensions and doesn't modify your file or the price.
  7. stop4stuff
    stop4stuff Well-Known Member
    If your software does not have units of measurement (mm, meters, inches, feet, etc) treat one on-screen unit as whatever you want it to be (mm, meters, inches, feet, etc) then use some software like Accutrans3D or NetFabb Basic to check your measurements before uploading - this way you save the hassle of uploading/waiting/looking/scaling/re-uploading.

    I learned the hard way too, to start with I was converting to Collada .dae then uploading, but more often than not the size was different to what I was expecting so I learned to use Accutrans3D to scale the model to the right size and then further down the line I figured out that I could just treat one unit as one mm, convert to .stl and select mm from the upload dropdown.

    This 'sizing issue' crops up frequently, whether it be a misunderstanding of what is shown, actual model upload size, or a cross-over between inches & mm... perhaps a tutorial is in order :)

  8. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    Hop to it :p
  9. Dragoman
    Dragoman New Member

    Trying to explain it fairly simply:

    Various 3d-Software packages and file formats do not support regular measurement units such as "Meters", "Feet", "Inches" or "Millimeters". They just use an abstract "Unit" that you can interpret as anything from Nanometers to Lightyears, if you wish.

    When you upload such a file to Shapeways, the system asks you what actual measurement unit your file's "Unit" represents. IIRC, it offers a choice between Meters, Inches and Millimeters. Shapeways uses this to convert the File-units into the actual dimension of the object and to control the printing so that it comes out the correct size.

    On the other hand, the display page only displays dimensions in Inches or Centimeters. The system automatically converts the unit you entered when uploading. If you entered "Millimeters", the numbers of centimeter will be 1/10th of the FIle-Units, the INches will be 1/25.4 of the File Units.

    An Example:
    You want something that is 5 cm long (not quite 2 Inches)
    You design it in millimeter units, so it's 50 "Units" long.
    On uploading, you enter "Millimeters"
    The printed object is then printed 5 cm/50 mm long.
    On the website you see "5 cm" or "1.97 Inches"
    - Everything is OK

    If the numbers of cm/Inches on the website does not corresponds to the size correctly converted to cm/In, you have a problem and its time to ask for support.

    I hope this helps

    Karl Heinz