(3DP) Damage tolerance

Discussion in 'Digital Design and Fabrication' started by rcengr, Nov 4, 2014.

  1. rcengr

    rcengr Vendor

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    This last weekend I let the club shoot up my pretty Potemkin, which has a mostly printed superstructure. Overall I think it held up pretty well.
    It's interesting what how small a target can get hit. The bollards are about 3/16" in diameter and I had at least 3 shot up like this one. There may have been more like this, but the entire bollard is missing in three other places. The hatch only sticks up 1/16" above the deck, yet it was clearly hit. The face of the turret took light damage.
    [​IMG]
    My two steam launches took a lot of hits. The other one was blown off completely and lost its stack. This one took two direct hits and never moved. The gunwale is slightly splintered, but easily repaired. The BB that glanced off the bottom of the hull still put a sizable dent in the wood superstructure.
    [​IMG]
    I lost 4 of my 12 air intakes, but they are pretty small and not expected to survive a direct hit. The stacks are also very light - just one thickness of plastic, about 0.42mm or 0.016". So I actually expected them to disintegrate when hit. The entry hole is pretty big, but the stack held up fine. So I'll use a single perimeter, no fill, to print superstructure for small ships that need a lightweight superstructure, like destroyers.
    [​IMG]
    The exit hole. Bigger, but a little thin CA and paint and no one will know.
    [​IMG]
    I got the splinter shields shot off twice. No damage to the splinter shield, so I need stronger glue. This picture shows that the dents to the 3DP structure was about the same as the dents in the wood (poplar) structure.
    [​IMG]
    I'm pretty pleased with how the 3DP superstructure worked. I can have a more detailed superstructure than I would normally do and still not be concerned about it being damaged, since I can just print more. Plus it was a source of entertainment at the battle... after each sortie we would gather around to see what had been shot off.
     
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  2. DATDAVFred

    DATDAVFred Member

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    ooh the sanity
     
  3. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    I did an article in Task Force 144 where I posted pics of destructive testing of my QE stern SS. What I learned from that was to make my splinter shields 6mm thick at the base, and thinner at the top edge so that they look scale from 5-10 feet, but take hits better. Vertical walls within 3 inches of the deck are about 6-8mm thick, and get thinner as I go up, but no thinner than 3-4mm. Horizontals are only like 2-3mm. Might be overkill, but that's what I go with because I hate mucking about with SS :)

    I also paint the parts with acetone to strengthen them.
     
  4. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    ** Mod Note: This post and the 8 following it were moved from another topic. If @Tugboat seems to be repeating himself in this post, it wasn't an because he is crazy, but because his post started life somewhere else. Part of this post was also removed as it applied to the original topic - that part was left on the original topic**

    Note that I did destructive testing more than a year ago... :rolleyes: and posted it in TF144... :rolleyes:

    ABS, suitably thick, is plenty BB-proof, especially if you acetone-treat it. 3mm wall thickness with 40% infill is plenty as long as the structure is at least 1/4" thick. When I tried 1/8" thick splinter shields, you could get interlayer separation from close-aboard hits from a well-tweaked gun. I have taken ricochets to the nuts to test this at like 6" of range on a printed piece that was held down firmly. Pics of the results are in the TF144 article.
     
    Last edited by a moderator: Oct 8, 2015
  5. irnuke

    irnuke -->> C T D <<--

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    I really don't want to see "pics of the results" of ricochets to the nuts
     
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  6. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Too late, I'm uploading them as we speak...
     
  7. NickMyers

    NickMyers Admin RCWC Staff

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    For those who don't want to go digging through the TF144 archives to find this, I've attached the issue with @Tugboat's article.
     

    Attached Files:

  8. dietzer

    dietzer Admiral (Supporter)

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    Out of curiosity, are the TaskForce144 articles archived anywhere online? Since shutting down, the MWCI removed everything from their website...
     
  9. NickMyers

    NickMyers Admin RCWC Staff

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    They're all up at the Southeast Attack Squadron's website. I have half a mind to mirror the repo, but don't want to step on Brian's toes.
     
  10. irnuke

    irnuke -->> C T D <<--

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    Brian is a college dean. As such, he's got steel-toed shoes & flame-retardant underwear. But feel free to ask him. I'm sure he'll say "yes".
     
  11. Bob

    Bob Well-Known Member

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  12. NickMyers

    NickMyers Admin RCWC Staff

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    This is A turret on my Derf last battle. I took a lot of fire across my bow from a pair of NC's The barrel that has been dented is thickwall brass (dummy barrel). The turret is ABS, 1.6mm walls I want to say 1.6mm walls (don't exactly remember if it was 1.2 or 1.6mm). It did receive a little cold acetone vapor treatment, but primarily focused on the top (note rounding of the view ports). None of these dents would I declare that the print has failed. The poor twin bollards on the other hand, of all 3 that were in the bow area, all three had the aftermost bollard shot off.
    20150927_135256.jpg
    20150927_135305.jpg
     
    Last edited: Oct 8, 2015
  13. Bob Pottle

    Bob Pottle Well-Known Member

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    No matter how small the details they can be shot off. My first models were highly detailed, with breakwaters, bollards, white metal deck hatches and W/T superstructure doors, anchor chains and winches, small MGs, galley chimneys, small deck ventilators, Carley floats, etc. After 4 years of use nearly every small detail on monitor HMS Terror had been shot off or damaged. The details on HMS Courageous also disappeared fairly quickly, so all models I've built since have had relatively few fine details. I still use bollards but they're brass instead of plastic, and instead of being broken they get shot off completely!
     
  14. NickMyers

    NickMyers Admin RCWC Staff

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    Thats one of the perks of 3d printing. I can run off a few dozen bollards for pennies and very little effort. One gets shot off, just scrape off and glue a new one on. Same thing for other parts.
     
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  15. Reckless

    Reckless Active Member

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    ^^^ that right there... that's the appeal of 3d printing to me personally.... sure the parts might not have all the same strengths as a FG or resign'd carved block... but if it's wrecked... press a button and glue a new one on!

    honestly alot of the peices printed are doing ALOT better then I thought they would, excellent research and in field testing guys! love it !
     
  16. Xanthar

    Xanthar Active Member

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    Per this challenge, I'm printing the stack from rcengr's Dunkerqe for some destructive testing.
    The first part will be coming off the printer in about an hour.
     
    Last edited by a moderator: Feb 14, 2017
  17. NickMyers

    NickMyers Admin RCWC Staff

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    While I'm interested in seeing the results, I will remind everyone watching that results WILL vary as a result of a mess of factors.
    Perimeter count and thickness, layer thickness, print temp, print environment temp, part size, orientation, filament choice/manufacturer/lot, moisture content, and more all will have an effect. Color even can modify the final result. In other words, whether @Xanthar's test prints result in indestructible or extremely fragile prints - or anything in between - one cannot cannot blindly apply that result to other prints.

    tldr;
    Home manufactured plastic goods will have varying physical properties.
     
    Last edited: Feb 14, 2017
  18. SnipeHunter

    SnipeHunter Well-Known Member

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    Fixed that for you.
     
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  19. Xanthar

    Xanthar Active Member

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    NickMeyers & SnipeHunter are absolutely correct.
    What I'd like to develop are some guide lines for what works well.
    Initially, I'm going to print this same part in a few different materials and see how they fair.
    I'm hoping that other people will 3D print the same part and have it tested the same way.

    First print is done. More to come. @jadfer PM me your address and I'll send it to you.
     

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    Last edited: Dec 7, 2016
  20. NickMyers

    NickMyers Admin RCWC Staff

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    Ship them all to @jadfer for science?