Shrinkage and WSF

Discussion in 'General Discussion' started by jkokkonen, Mar 29, 2012.

  1. jkokkonen
    jkokkonen New Member
    Hi,

    I 'm planning to use 3D-printed parts in my hobby project. I uploaded a test model to Shapeways and received it printed. I'm very happy with the material and finish but have a question about shrinkage.

    http://www.shapeways.com/model/461201/ac11dbb6eca626bbfd27c7 51b6c1841a.

    Shapeways model checker showed the dimensions as cm: 4.36 w x 6.46 d x 5.22 h which is correct. When I measured the printed piece it was 4.29 W x 6.25 d x 5.06 h so the shrinkage varied from 1.6% to 3.3% in different directions.

    Is this what I should expect? Or was I unlucky? I glanced the forums and found conflicting answers to this. One of the tutorials appears to say that shrinkage is taken care of and should not be a problem, of course to a certain accuracy.

    I think I can work around that amount of shrinkage but should I be prepared for even more? Or even expansion?

    jkokkonen
     
  2. stonysmith
    stonysmith Well-Known Member Moderator
    It seems that you've got the model marked private. (or you deleted it)

    You should expect some shrinkage on any model The various Design Rules pages list the shrinkage for most models. I've suggested that they move this shrinkage value to the main materials page(s).

    The shrinkage should be fairly standard.. it shouldn't vary (much) from one order to the next.
     
  3. jkokkonen
    jkokkonen New Member
    Thanks!

    I had not found the "display to the public" option before. There is not much to see, though. Just a scaled down and simplified version of one of the parts I need.

    I think "Designing mechanical parts, part I" in Tutorials gives a bit optimistic view of what to expect about shrinkage.

    jkokkonen
     
  4. abby
    abby New Member
    This amount of shrinkage is not acceptable and I would contact customer services for a re-print.
    I have had only 1 experience of this amount of model under-sizing and it was quickly replaced FOC.
    I add 2% to my patterns as they are used as masters for metal castings.
     
    Last edited: Mar 30, 2012