Dimension wrong

Discussion in 'Design and Modeling' started by rezlo, Nov 24, 2011.

  1. rezlo
    rezlo New Member
    Hi all,

    Ive just created a simple box, just to get a rough idea of cost etc,
    i have max set to mm scale, and when i upload i choose mm.

    the box in max is 200x200x30 but after its uploaded its listed size is
    0.8x0.8x0.1 with cm selected
    just wondering if im doing something wrong??

    the file is exported as a .stl

    Attached Files:

    • box1.STL

      File size:
      684 bytes
    Last edited: Nov 24, 2011
  2. pfeifferstylez
    pfeifferstylez New Member
    As far as I can see the box is 7,87 x 7,87 x 1,18 mm ...
    Which software did you use ?
  3. BillBedford
    BillBedford New Member
    You software seems to be exporting the stl in inches. Try using inches when you upload to Shapeways.

  4. Sol3
    Sol3 Member
    STL doesn't care what measurements you're using on-screen. You need to set your upload to your system units measurement, in which case you're probably using inches, (which is the default), even though you may be using mm for your designs.

    To make it less confusing, you might want to set your system units to mm, which also seems to give you more precision.

    But when you import or open others' models or scenes you may get a warning about the system units being different.
  5. stonysmith
    stonysmith Well-Known Member Moderator
    In your software, create a cube with sides=1, centered about (0,0,0).

    Export it as an Ascii STL and edit the file with Notepad or your favorite editor.

    You should see a bunch of lines that look like this:
    vertex -0.5 -0.5 0.5
    vertex -0.5 0.5 0.5
    vertex -0.5 -0.5 -0.5

    If the values are 0.5 (one half unit) then your software is exporting the STL correctly. If they are NOT 0.5, then your software is changing the scale before it exports the STL.

    As has been said many times, the STL format is actually unit-less. It doesn't carry Meter, CM, MM, Inch nor ANY indication of units. When uploading to Shapeways, you are asked what unit that you want "0.5" to mean. If your software is doing some kind of conversion, then you'll need to adjust accordingly.

    If your software just refuses to give you control, then I'd suggest downloading a copy of the free NetFabb Studio Basic.. it can easily enlarge/shrink your models so that you can achieve a successful Shapeways upload.
  6. BillBedford
    BillBedford New Member
    The difference in size between what the OP expected and what he got was out by a factor of 25.4.
  7. Magic
    Magic Well-Known Member
    If as I understand you are using 3DS Max, you have to know that 3DS Max has two kinds of units: the display unit and the internal unit.
    Check the "Units Setup" menu item of the "Customize" menu. It opens the "Units Setup" popup window that has a "system unit setup" button (first button). Click this button and set 1 unit to 1 mm.
    Should work better... :)

    Last edited: Nov 24, 2011
  8. Sol3
    Sol3 Member
  9. rezlo
    rezlo New Member
    Hi all thanks for all your quick replies, ill be sure to double check what im trying to change, but it does seem im not changinging it in the right spot.

    Thanks again =)