How long until we see 3D printed components in boat building?

Discussion in 'Boat Design' started by Timothy, Dec 16, 2013.

  1. Baltic Bandit

    Baltic Bandit Previous Member

    IOW non mission critical parts, in a custom environment where efficacy is at a premium over cost. Remember that typical industry runs at a Fiscal Multiplier of over 2.0 for product production, whereas DoD Procurement for existing systems runs around 1/3 of that
     
  2. capt vimes
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    capt vimes Senior Member

    metal is either cast, extruded, rolled (that is your aircraft panels), sintered, forged or in extreme cases grown to a monocrystalline structure (usually only used for jet turbine compressor fins because it is a very slow process)...
    i choose to mention the fabrication processes in that order, because it represents the strength of the material once finished - although with sintered metal you can go up to the same strength as with forging...
    some metals/alloys cannot be treated with one or the other fabrication process, depending on the metal/alloy...

    you forge metal to always reach better material properties... it has nothing to do with "smaller input stock"...
    the big canons on those battleships of old were all forged because no other fabrication process would provide the appropriate material strength - you CANNOT cast or extrude the actual muzzle... well you could but just to watch it go to pieces with the first round fired... ;)
    heck - the wheels of racing cars/motorbikes are milled out of a solid, big and overall _forged_ block of magnesium alloy...

    there are various types of 3D printers out there but we have been talking here about laser sintering, and those do not produce any waste...
    it is simply metal or ceramic powder sintered together by means of a laser - the excess amounts of powder goes back into the tray from which it came...
    it is an additive process where layer after layer is sintered together...
    here is something to read for you:
    https://www.mpif.org/DesignCenter/mech_props.asp?linkid=50
    http://en.wikipedia.org/wiki/Direct_metal_laser_sintering

    initially i might have misunderstood the word "billet"... thinking more of a bar or ingot (which are all only cast!) and not in terms of a more generalized word where a forged block could also be called a "billet"...
     
  3. Baltic Bandit

    Baltic Bandit Previous Member

    um you have sintering in the wrong order. Unless it is post treated, sintered products are weaker than cast.

    And yes there is waste. precisely because you are relying on the laser to lay down the shape into a "cloud" of "dust" the "dust" at any particular layer that does not get sintered becomes waste.

    The excess powder does not "go back into the tray" if you want a high strength product. why? because as it is adjacent to the heating it contains oxidized metal which is weaker than the new stuff.

    In the plastics printing it can go back in the tray, but even there you have some waste (for a variety of reasons).

    Note also that DLMS requires quite a lot of power so again, you could stick it on a mid sized cargo ship but not something smaller
     
  4. Stumble
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    Stumble Senior Member

    Weird that you mention it, because every person that makes DMLS machines, and everyone I know with them specifically mentions reusing the powder. Apparently you have knowledge about these machines that the manufacturers and users don't.

    Secondly, I really wonder where you are getting your strength data from. The lab reports I have seen indicate strength retention without post fabrication heat treating within 1% of milled parts. In some alloys and geometries the strength is actually higher.

    But since without HIPPING parts already are at 99.99% density, this is to be expected.

    If you have hard data, please share it, I am willing to learn more, but your contentions are directly opposed by the engineering data I have seen.
     
  5. Baltic Bandit

    Baltic Bandit Previous Member

    I'm going on what the MFGs told me at the tradeshows where they and I were presenting - but that was about 5 years ago for the direct info, so they may have improved the process. Also there is reuse during the sintering process, but once the part is done, and you pull the part, the excess material around and in the part does not get reused. so its a mixed story on the re-use.

    I'm not so sure on the milled vs sintered parts being 1%. a lot does depend on the feedstock of the milled part and even the alignment of the source material WRT the loads being used.

    But we are spinning into the weeds on this. for parts and geometries that are complex eough that sintering can result in stronger parts, you are talking about serious CAD skills needed and you aren't going to be downloading those CAD files to a 50' yacht stuck at anchor in some remote cay or atoll.

    Does it make sense that a custom builder of yachts have a DMLS and a 3D plastic printer? Probably.

    But that's a different discussion than the one we've been having
     
  6. Stumble
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    Stumble Senior Member

    There have been a lot of advancements in DMLS in the last five years. As an example, let's take a look at 316L stainless in two forms 1) the specs given by matweb, and those from one of the DMLS machine manufacturers.

    ......................................Yield..........tensile...........elongation at break
    1) ASTM A240/A240M......170MPa.......485MPa..........40%
    2) DMLS - 3trpd..............420MPa.......595MPa..........44%

    The ASTM A240 is for flat rolled mill stock plate. The numbers from 3trpd is as build (no post manufacturing processing).

    http://www.3trpd.co.uk/wp-content/uploads/2013/03/316l-stainless-steel-2012.pdf


    Not being a metallurgist I am hesitant to guess why the DMLS part is stronger, but my guess is it has a lot to do with the effect of the inter granular boundaries size difference created by the DMLS machine when compared to mill stock, and possibly with residual oxygen bound to the chromium duringt he milling process.

    As for gettingt he parts... I have looked into it, and for about $100 you can get access to the CAD drawings of many major engine manufacturers. I doubt that this would allow you to make an internal engine part because the tolerances aren't tight enough without post production finishing, but it would allow you to make pretty much everything else.

    Last time I looked Harken will provide you all their SolidWorks files for free. And for about $1000 you can buy a 3d scanner (8"x8") that can create a SolidWorks model from anything you stick into the scanner.

    Do I think this is ready for a 50' yacht yet? No far from it. The machines are too big and too expensive. But would it work on a 50m yacht? Probably.
     
  7. capt vimes
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    capt vimes Senior Member

    https://www.groundcontrol.com/Fleet_Broadband.htm
    you do not need to lie at anchor - you could do it from anywhere (apart from polar regions) and well on your way in a yawing, pitching and rolling craft... it does not matter because the antenna is orienting itself to the signal... ;)

    welcome to the 21st century...
    for the rest - stumble has posted it.
     
  8. Baltic Bandit

    Baltic Bandit Previous Member

    A) the bandwidth isn't there
    b) no one will give you the files
    C) you cannot run the DLMS while pitching and yawing that way.

    I'm more on top of the 21st century than you are. I actually do business in this field - though not directly in 3D printing. Rather than just reading Popular Science and similar, I actually talk to folks using this stuff.

    It has its place. As a way of making un-certified SS bolts at 100x the price of a pulled and die-formed one - that's not one place.
     
  9. capt vimes
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    capt vimes Senior Member

    this is the threads title "How long until we see 3D printed components in boat building?" isn't it?
    it does not read "ON a boat", does it?
    i simply replied to your statement, that you cannot download the cad files on a 50' yacht stuck at anchor in some remote place... nothing more, nothing less.
    you can and there is absolutely no CAD knowledge required to do so...
     
  10. Baltic Bandit

    Baltic Bandit Previous Member

    I can see how you misread my post. It is possible technologically to download the files.

    a) you cannot do it because you aren't going to be given those files (see earlier discussions on this)

    b) its expensive to do

    c) no 50'er is going to waste the space to carry a DLMS system.
     
  11. Skyak
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    Skyak Senior Member

    Be careful about free CAD models -they are most likely packaging models, the simplified models you need to create assemblies. Everyone gives those away for free. It's a modern requirement for every OEM. STL files will be provided as needed as part of warranty program someday but I am not sure yet and you will need to prove you bought and broke their part.
     
  12. Baltic Bandit

    Baltic Bandit Previous Member

    Even the $100 cad drawings for engines is a packaging model. I know because I know how tightly guarded even the packaging CAD files for one of the motors from one of the domestic mfgs was when I sought to get one for a demo. Heck I couldn't even get the Inventor guys to give me the CAD model for a weedwacker motor.
     
  13. Stumble
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    Stumble Senior Member

    This is a major stumbling block sure. My guess is if you went to a major builder and asked for access to the real files you would have to pay a licensing fee for the privilege. And it may be somewhat manufacturer specific.

    For many small parts however the actual files are readily available. The files for pretty much every normal fastener are available online for free. Now Baltic is right making them this way would be vastly more expensive than the cost of buying them at even WestMarine. But I am not sure that the cost is that much more when you count in the inventory holding costs, space allocation, both of the specific part you need and all the other similar size bolts than need to be held in inventory, often that never get used.

    On a 35m yacht I worked on we had hundreds of small bins, holding thousands of small nuts and bolts (it basically looked like the hardware aisle of WM), just to ensure we had everything we would need when something broke. Just replacing that wall would have saved substantial amounts of money, weight and space.
     
  14. capt vimes
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    capt vimes Senior Member

    what the heck is wrong with you?
    may i read my previous post back to you?
    i'll do it anyways, no need to answer this one... i marked the essential part.
     

  15. Yellowjacket
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    Yellowjacket Senior Member

    In an earlier post I mentioned that CAD files don't have the detail you need to print things like fastener threads. Yes there are tons of fastener files out there, but open one up and you will see that all you have in the file is the head and the shank. The CAD file has a callout for a thread that is attached to the model, but that is so when you go to make a drawing of the part the thread callout is on the drawing. There is nothing in the CAD file that will tell the printer what that thread looks like, so you really can't make any threaded fasteners unless you have a CAD program to make a model of the thread. And you need to know how to use the CAD program, or you won't be making threaded fasteners. Oh and since you aren't an engineer you won't know how to figure out the thread dimensions. Maybe someone could put these into a CAD program, but they don't now because it would bollix up the system with many more surfaces and that would slow down the program.

    It is also important to note that threaded fasteners in high stress locations need to be torqued to a high enough static load so as to prevent fatigue failure. How much torque can you put on a fastener that you just made yourself? Do you know the yield strength of that batch of material? Do you know the strength of the original part that is broken??

    And any engine part is likely to require post processing, either by machining, hipping, or heat treatment.

    The parts made by this process are basically "Chinese copies".. That is, they look like the real thing, but may or may not be strong enough to do what you want to do with them. With a factory made fastener (a quality one, not a hardware store piece), I can trace the material back to the mill and know that I have good hardware. With Chinese made hardware you have none of that and the results are predictable.

    In short, forget threaded fasteners, making one isn't a good idea in the first place, even if you had the data to actually make it (which you don't).

    It is often said that a person who represents himself before the law has a fool for a lawyer. The same can be said here in that a person who, without training as an engineer, goes out and tries to make parts that he is staking his life on, is likely to suffer the fate of a fool at sea.

    This all sounds nice and the folks a Popular Science would have you think that this stuff is right around the corner, but really, think about it. If you want to make a cleat or a piece of hardware that isn't critical, knock yourself out and have a nice time. Make some brackets to hang a picture on a wall, sure, go for it, a flange to hang a hose onto, maybe.

    But for real hardware that could cause you harm if it were to fail, it isn't going to happen. The legal system would crucify anybody that tried to make an important part and had a failure and rightfully so.

    So now you are left with making parts that are not critical, or parts that may be hard to find in a remote port. Oh, and these parts are going to cost you roughly 10x the cost of a factory made part. Don't be silly. It isn't going to happen for a small personally owned boat. The Navy could do it, because they would call up the engineering section and have an engineer look at the situation and tell them what it needed to be to do the job, but a person in a yacht doesn't have that luxury.
     
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