Does Shapeways use metric or imperial, or both?

Discussion in 'Design and Modeling' started by olliedale, Aug 16, 2013.

  1. olliedale
    olliedale New Member
    I've uploaded a design and requested it be printed in two different materials, White Strong & Flexible and Gold Plated Glossy.

    Both requests were declined, with the diagrams below as visual aids...

    White Strong & Flexible
    Reason: Thin walls
    Additional information: The minimum wall thickness for this material is 0.7mm. Please thicken the walls of the model. The minimum thickness for free wires > 1.0mm and supported wires > 0.8mm for this material.

    And the diagram below says Look, the record is 0.66 and needs to be 0.8

    And then

    Gold Plated Glossy
    Reason: Thin walls
    Additional information: The model is too thin to print. Increase wall thickness to at least 0.03" / 0.762mm in all areas.

    And the diagram below says Look, the record is 0.0258 and needs to be 0.04

    Why on Earth would these values be different? Are you mixed up between mm and inches? Do you know how hard it is to get a designer to get this 3D Design right when I told him the minimum should be 0.04 and he comes back and says "it's already 0.66 which is way bigger so any further changes are chargeable"

    Very irksome.

  2. mkroeker
    mkroeker Well-Known Member
    Maybe they have an intern from NASA :D
    Seriously, as long as the unit is specified (or at least obvious from context) I see no problem with this
    when there are some fossils still around who think in limb dimensions of some long-gone king instead of
    the arbitrary but consistent system of some long-gone revolutionaries. (Wikipedia tells us that this axis of
    evil runs through Liberia and Myanmar in addition to a certain north american country).
    Lastly when somebody tells you to increase your .02 inch dimension by 0.01mm, he might just be a cyclist. :D
  3. AmLachDesigns
    AmLachDesigns Well-Known Member
    ??? (I think I get the other allusions...)

  4. mkroeker
    mkroeker Well-Known Member
    Well, where else than on a bicycle is it relatively common to find a wild mixture of imperial and metric parts ?
    (Or so I am told, actually I prefer to be higher up in the food chain when on the road)
  5. cellophaan
    cellophaan New Member
    I suspect you made an error when you uploaded the model.
    After the model has been uploaded, you need to select if the model is in inches or mm.
    mm is the standard selection, so if you don't change it, shapeways will use mm.

    The first image shows that the disc is indeed 0.66 mm where I would think your designer intended it to be 0.66inch.

    The second image is a bit more complicated, because the shapeways person used inches in his model display.
    it shows a thickness off 0.0258inch, which is the same as 0.66mm. Again, shapeways reads 0.66mm instead of 0.66 inch, and in their modeling software, it showed 0.66mm as 0.0258inch.

    So it seems to me that the culprit is shapeways reading your model as modeled in mm instead of inches.

    So I'd suggest to try reuploading the model, then make sure you select inches as the model unit, and try printing it again.

  6. olliedale
    olliedale New Member
    Thanks for your awesome reply.

    Unfortunately it's invalid as I only uploaded 1 model, and requested it in 2 materials.

    Good guess though. Would you like to have another guess?
  7. mkroeker
    mkroeker Well-Known Member
    Not sure now what you are complaining about - regardless of whether the particular worker out of shapeways' pre-print checking group had his software
    setup in inches or centimeters, the advice given in each case appears to be valid and consistent to me. If it is the combination of standard message text
    and specific information that bothers you, i would read it as "minimum wall thickness is generally ... and in the particular case of that disk it has to be a bit more as it sticks out so much.
  8. olliedale
    olliedale New Member
    The issue for me was that one of the models didn't have units defined, while the other one did.

    So when I wrote back to the designer and told him, from the diagram I'd seen, another measurement that didn't indicate that it was a different unit, his reply was that the model was already larger than that...

    When you're dealing with someone who charges for changes this was an unsatisfactory outcome. Yes, on closer inspection, this is an obvious difference, but I'm not from your 3D world, and it wasn't obvious on first glance - I simply forwarded the number as it was on the diagram. If it had had units that would have helped.

    Which brings us all back to the point - why have two units of measurement? And if you're going to have two units of measurement, why have diagrams that don't define those units?

    In this instance that resulted in an undesireable outcome for me, costing me money. All I'm suggesting is one or the other.
  9. FreeRangeBrain
    FreeRangeBrain New Member
    "... - why have two units of measurement?"

    Because the United States of America insists on sticking with an antiquated system of measurement. Mind you, so do Liberia and Burma, so at least they're not alone.
  10. MrNib
    MrNib Well-Known Member
    My two cents on the subject is that there should be a corporate standard for units when dealing with customers, and yes, at the very least a corporate standard should mandate that units are always included in correspondence. That's especially true for a company that operates internationally. It is very wrong to not include units although it is also very wrong to forward a number without units. -5 points to Shapeways for being sloppy and -5 points to olliedale for overlooking the sloppiness. That's what my students always get when omitting units. In bold red marker!
  11. bartv
    bartv New Member
    Hey guys,

    I asked around and here's the reason for us using both mm and inches in these screenshots: we're working with different suppliers for our materials. and each supplier does the model checking for 'their' orders. In the case of Stainless Steel, we're using a supplier in the United States, so they use inches. For WSF, we check the models and we always use mm (our NYC branch included).

  12. mkroeker
    mkroeker Well-Known Member
    Interesting, as it seems to shed some more light on the (assumedly) spurious rejections that people complain about. (In particular the
    cases where a model printed in some material without apparent problems, and then got rejected in another material that may even
    have less stricter design limits)
    At least I had previously assumed that most if not all pre-production checking was done by shapeways personnel (implying common ruleset and casual communication between team members) and only (some of) the actual printing was outsourced.