Hollowing out does not change price

Discussion in 'Technologies and Hardware' started by Shef_, Feb 27, 2013.

  1. Shef_
    Shef_ New Member
    I'm working on a case for the iPod nano 6 that would essentially turn it into a pocketwatch. The problem is that since the case needs to be 6cm diameter (the diagonal of the ipod), it ends up being almost $50 for the case.

    I went back to blender, and started hollowing it out (by adding meshes inside the mesh itself, essentially making it hollow), but the price does not change one cent.

    I'm talking about WSF, not some fancy material, how does something like that end up being so expensive? and why does hollowing it out not affect anything?


  2. stop4stuff
    stop4stuff Well-Known Member
    If your model were a solid 6 cm dia x 1 cm thick, it would be a little over 28cc & under $50 - are the units of measurement and the dimensions correct on the model page?

    For hollowing out, you need to connect the inner shell to the outer shell with a tunnel or hole that forms the 'escape hole' for the support material after printing - no escape hole = not hollow model.

  3. Shef_
    Shef_ New Member
    Thanks for the reply. I'm pretty new to this whole thing (even though I've been subscribed for so long, I didn't really think about it).

    I did calculate it to be approximately 50, too. I have a question then, if it's alright to ask.

    i.materialize seems to have options in about the same sizes for a much lower price, how are they able to do this, then? Is the quality different?

    (Is it alright that I ask about a competitor on here? I'm simply curious.)

    I'll try again tomorrow with a hollow model.

    Oh, last question: how big should the hole be?


  4. stop4stuff
    stop4stuff Well-Known Member
  5. AmLachDesigns
    AmLachDesigns Well-Known Member
    Oops, too slow--->

    For hole size for Strong and Flexible plastic (polished and unpoilshed) (Strong and Flexible Design Guidelines):

    Min Escape Hole: 4mm (1 hole), 2mm (2 holes), Big models (multiple holes)

    Have you checked that you are comparing like with like? In the past, for a same sized model in the same or similar material, my experience is that they are more expensive. If this has indeed changed, that would be interesting.
    Last edited: Feb 28, 2013
  6. AmLachDesigns
    AmLachDesigns Well-Known Member
    As an example (just checked) my Potentiometer Scales from Shapeways cost 9.82 eur in wsf and 11.94 eur in Alumide.

    From the other site, the same .stl file gives prices of 12.50 eur and 15.00 eur respectively (assuming that wsf equates to PolyAmide and Alumeide is the same on both sites).

    This does not take into account any volume (bounding box packing) discounts.
  7. Shef_
    Shef_ New Member
    So, i.competitive service's pricing seems to be a different model: If it fits within a certain volume, it gets x price, no matter the actual volume.

    The scales you showed and my pocketwatch both fit within the 125cm^3 volume, so they get charged the same no matter what.

    I'm staying with shapeways though, as the quality is apparently better and the detail is nicer, and that's what's the most important to me. Plus the fact that the price for shipping totally kills their price advantage over shapeways, so it's not even that much of a difference at the end.

    Anyways, what materials would you guys think an ipod cover/pocketwatch should be made out of? I'm planning for WSF or CSF, seeing as it does need to safely hold an ipod, but I don't know much about this.


  8. Fredd
    Fredd New Member
    with the volume not changing I wonder if it the face normals are not correctly oriented.they are very important for defining material volume.you can attach the blend file here in a post if you want someone to take a look at it.The Solidify mod is nice for creating wall thickness in Blender
  9. Shef_
    Shef_ New Member
    I figured out how to hollow it! Thanks everyone! I'll make a few more adjustments then post it in WIPs.

    Right now I'm just waiting for blender to start responding again (I accidentally clicked on skin instead of solidify in a highly subsurfed model :cry:
  10. stop4stuff
    stop4stuff Well-Known Member

    Shapeways Mesh Medic sorts out the normals ;)

  11. Shef_
    Shef_ New Member
    So I'm almost done. Front face is completely finished, back face still needs a bit of work, because I'm not sure what to put on there. I'll post a render later this evening (PST).