Safe To Print This?

Discussion in 'Other Interest Groups' started by 0x00019913, Oct 1, 2016.

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  1. 0x00019913
    0x00019913 Active Member
    Hey, folks, quick question.

    I made this: https://www.shapeways.com/product/5PBQPC6G3/antelope-skull?optionId=60881138. (You all can access that page, right?) I wanna print it in metal, let's say stainless steel.

    The site warns that some parts are too thin. Specifically, that front part of the skull, the bone wrapping around the back of the eye socket, and the end of the horns all show up red on the wall thickness map.

    Does anyone have any thoughts/experience on pushing the boundaries of the recommended wall thickness? I'm pretty sure I could print this at 0.1mm on a Makerbot because I've done things like this before. I also don't mind too much if the horns break off a bit at the top, I can shape them with a file.

    Full model: https://sketchfab.com/models/764517aec4364dfc8cbf454c57ed1d35
     
    Last edited: Oct 7, 2016
  2. NoahLI
    NoahLI Well-Known Member
    Stainless steel isn't anything like steel filament. Finish process is nothing like FDM.

    1mm minimum is very strict with stainless steel. You might slip through at ~0.98mm. But anything less will most likely get rejected. I would reduce the length of the horns a bit and add more thickness toward the tip. Nasal cavity and eye sockets will need to be thickened all around. If you really want the sharp tip on the horns you'll have to file or grind it down after receiving the print. Stainless steel in green state have to get packed in sand for bronze infusion, and will have to endure some stress during packing. The horn will probably break much more than just the tips.
     
  3. 0x00019913
    0x00019913 Active Member
    Yeah, that makes sense. I figured the "green state" aspect would cause problems when I was reading about this.

    What about, say, this? That pendant, among many other models, is small and has very fine detail. I guess it's because it's printed in a "raw" material - just a lower required wall thickness for the particular material?
     
    Last edited: Oct 2, 2016
  4. NoahLI
    NoahLI Well-Known Member
    Those are lost wax cast. model is printed in wax, sprued and encased in plaster, then the plaster shell is heated so the wax burns out leaving space for molten metal to flow through. entirely different process. It allows smaller details, but much more expensive than Steel
     
  5. 0x00019913
    0x00019913 Active Member
    Ah, that's cool. Thanks for the replies. :D

    Also, if I arrange the geometry such that the whole model is green and otherwise soundly constructed, should I expect that the model will get printed and successfully shipped? Like, I won't get a model that just randomly happened to lose a horn in the process?
     
  6. NoahLI
    NoahLI Well-Known Member
    Mostly green with minor yellow in surface details is okay. Yellow in structural areas are a gamble. If something breaks during printing, after your model passed manual checks, SW will try to rerun the print for a few times. If it consistently breaks in the reruns they will ask you for redesign. You can tell if the model broke during printing by looking at the success rate after the first time you print it. 100% means it was successful on first try. You can estimate the number of attempts before a successful print by the percentage... e.g. a success rate of 33% meant the model was considered successful on the 3rd attempt.

    It's unlikely a fully broken horn would be considered a successful print, but I can't say for sure that it will never happen.
     
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  7. 0x00019913
    0x00019913 Active Member
    That's really good to know, actually. Much thanks for info. )
     
  8. UniverseBecoming
    UniverseBecoming Well-Known Member
    Nice sculpt! :D

    What you could do is fill in the nasal cavity and make those bone structures into an embossing. The way you have it looks great, but sometimes one needs to work with the limitations of the manufacturing processes. Same goes for the horns too. I'd try making them less pointy and also thicker.
     
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  9. 0x00019913
    0x00019913 Active Member
    Thanks. :D I did more or less that.

    Turns out, if I print in brass, I can adjust it to print with very minimal changes. Currently in production, shipping in ~2 weeks. Rather pricey, of course. XD
     
    Last edited: Oct 24, 2016
    NoahLI likes this.
  10. UniverseBecoming
    UniverseBecoming Well-Known Member
    Should be great in brass! Send picks when you get it. :)
     
  11. crnm
    crnm Well-Known Member
  12. 0x00019913
    0x00019913 Active Member
    Here. :) Will put up pics when it's delivered.
     
  13. 0x00019913
    0x00019913 Active Member
    @UniverseBecoming @crnm

    Phone camera is dead and tablet camera is potato, so here's the best picture I can take. Very pretty in brass. :D

    [​IMG]
     
  14. NoahLI
    NoahLI Well-Known Member
    very nice!
     
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  15. UniverseBecoming
    UniverseBecoming Well-Known Member
    Looks great! Thanks for taking and uploading the pic! :D