The Incredible Shrinking Model

Discussion in 'Design and Modeling' started by Oldmancat, Nov 23, 2019.

  1. Oldmancat
    Oldmancat Member
    I'm trying my hand at making some HO Scale parts. My test model is roughly 10mm x 10mm. I upload as an .stl file, and Shapeways rejects. Too small, I'm guessing.

    I enlarged the piece roughly 200 percent. The saved dimensions roughly roughly 23 x 23 mm. The file uploads, but the readout says it's 1.2 mm x 1.2mm! I resize to get the 10 mm part I wanted in the first place.

    I'm using ViaCad Pro 11 on a Mac. Maybe I'm missing some settings, but I'm open to any other troubleshooting ideas.

    Uploaded the file again to double check. The 23 x 23 mm model shrank to 1.2 x 1.2 mm. I thought it might have been giving me the size in centimeters. Nope.
     
    Last edited: Nov 23, 2019
  2. 8_Perf
    8_Perf Well-Known Member
    What units of measure are you creating the file in? Are you uploading the SW with that same unit of measure? I.E. Dont draw/ save in inches and then upload in millimeters. An STL file does not contain domension data, only units. Your item is X units long for example. Makes little difference to the file parser. It wont know you meant mm and not inches unless you tell it. Thats my first guess. Ive nver heard of the CAD program you are using. There may be something not compatible in there. Check all of your settings and preferences for output and try to get them to match one of the settings SW uses. I prefer mm for drawing, saving, and importing an STL. I also use Sketchup and have never had an issue. Perhaps someone that uses Fusion 360 or something else can chime in.
     
  3. Oldmancat
    Oldmancat Member
    I drew in millimeters and output the same. I thought VicCAD was fairly well-known, and it exports in any number of formats including .stl. Does Shapeways have a list of compatible CAD applications? ViaCAD comes from PunchCAD in Windows and Mac flavors. I've used it for several years. https://www.punchcad.com/
     
  4. Oldmancat
    Oldmancat Member
    I converted the file to inches. It uploaded, and I was able adjust the size. However, the final size was 25% larger than what it should be. It ended up .53 in/13.5mm instead of .413 in/10.5mm. Is the larger size of the model the minimum size to print?

    Supplemental: The size I wanted turns out to be less than the minimum bounding box for versatile plastic.
     
    Last edited: Nov 24, 2019
  5. 8_Perf
    8_Perf Well-Known Member
    Its not that SW is only compatible with some software, but rather that your software outputs to the correct file types that SW can use. Sounds like it does. Only other thing I can think of would be that when you upload the file, you might not be choosing the correct units. If its not that, I dont know what else it could be.

    I see above you might have found the answer in that your part is too small for the minimum bounding box. 10mm x 10mm should be a valid size though so not sure what is going on. Their own guidelines say your X+Y+Z dimensions need to be over 7.5mm to qualify. You are over that so it must be something else.
     
  6. czhunter
    czhunter Well-Known Member
    If the part is too small to print, it is tagget "unprintable" (for given material) by SW, but never scaled.

    Try to open the STL in internal Windows 3D print application (or Meshmixer or Netfabb or whatever that opens STL). Is the size correct there?