print quality and quality control

Discussion in 'General Discussion' started by tinarity, Jul 13, 2016.

do you complain about quality?

Poll closed Jul 27, 2016.
  1. yes

    80.0%
  2. no, I just don't come back

    10.0%
  3. no, I am just disappointed

    10.0%
  4. no, I don't care what I get

    0 vote(s)
    0.0%
  1. tinarity
    tinarity Well-Known Member
    image.jpeg After ordering a first print of my belt buckle 'connect' in polished bronze steel (left model) I got in touch with the SW team, because it had a dent (upper left corner of left model) probably from rough handling (certainly not from the model or the printing itself)

    SW offered to reprint the model, on which I happyly agreed as I planned to use this model as a showcase for a potential whole sale. Though the model itself printed fine, the printability rate dropped down to 67% with the second print.

    When the reprint arrived, I was disappointed to see it wasn't polished at all (right model). So I made yet another complaint to the SW Team. (By then the potential customer was put off by the time all this took and the extreme variation of quality.)

    SW team checked with the printing facility and came back with this comment:

    "I got a reaction from our printing facility regarding the model.

    ------------------------------
    The edges are rounded, so this was polished. Polishing varies based on how it is hit by the media.
    ----------------------------

    I hope this clears things up for you regarding the polished model.

    Regards,"

    the polishing must have happend in the lower right corner (right model) as I couldn't find another shiny bit on this model. (the edges are rounded in model itself btw)

    As this now happened at least three times (second print not polished, remarkable lower quality) I can't explain it away as bad luck.

    So long story short: you never know, what you get and you certainly will never know (or have any kind of control of) what your customers get.

    I will refrain ordering or offering any models in polished steel. As unpolished steel looks pretty crude for jewelry I will not offer that either. Which leaves plated (I saw models that close to my second print) or solid precious metals.

    Considering how much hassle it is/was to get something printed in the relatively economic priced metal, I dare not go through the whole process again where there is more money involved.

    disenchanted regards
    tina
     
  2. Youknowwho4eva
    Youknowwho4eva Well-Known Member
    Tina,

    I'm sorry to hear about your troubles. The process for steel is very difficult. I visited the factory where it's made, and it's an exciting but complex process. Using thin wires causes a couple issues. One, during the infusion process, gravity can start to work on your model when the glue is burnt off, and the bronze is being infused. Two, is with polishing. It's up to the people in the finishing room, if they feel the tumbler will damage the model. If they feel it will, they will hand polish instead. The next person could feel it will work in the tumbler. We're working on a way to make the finishing a more consistent process.
     
  3. tinarity
    tinarity Well-Known Member
    michael,

    sorry but I can't follow your reasoning. The model has been successfully printed and polished, so one would think your staff might know of that fact. Maybe a little note in your system would improve on your work processes and wouldn't depend on the feelings of your staff.

    Obviously your are stating you can't reliably replicate a model to the same quality, which then becomes a lottery (I am constantly loosing) and makes opening a shop pretty obsolete (it might even damage your name if you are a professional)

    If you can't print it, don't offer it.

    Your service-team keeps saying 'sorry' a lot. That might be a valid thing to say for an amateur printer but not for a professional company like you claim to be. I have by now two totally useless models, spent some money and a lot of time on it, lost a potential deal and all I hear is 'sorry'.

    Sorry, but that's not good enough
    tina
     
  4. mkroeker
    mkroeker Well-Known Member
    "Steel" is produced by a production partner, namely ExOne, the developers of the process. Even rushing to a competitor will most likely see your model end up in the same factory...
    Roughness and eventual sagging will depend on part orientation, apparently they have a choice between tumbling and bead blasting for polishing as well. See https://www.shapeways.com/forum/t/inconsistent-quality-shapeways.43328 for another recent tale of woe - in the end you are probably better off having such rather delicate parts printed in (wax and cast in) bronze.
     
  5. tinarity
    tinarity Well-Known Member
    ExOne might be the developers of the process, they might even have a monopole here but I am buying from SW. It's not my problem and actually none of my business at all, with whom they partner up.

    I am a customer and I didn't get what I paid for.

    By now I've lost the confidence so far that I won't try to get the print in solid bronze. It just involves more money and probably the same unpolished results because the finisher wasn't feeling up to it and SW will say sorry and that I have to understand how difficult their business is.
    Besides for wax and cast I can try lots of other companies (who might be a bit more willing to deliver quality).

    Here is just another case (I've got lots) of the same problem. First print nice and polished (left), I resized the model, second print (right) not polished, even though it's got thicker walls and is more sturdy. I am sorry but I don't see any logic behind this.
     

    Attached Files:

    he6agon likes this.
  6. Bathsheba
    Bathsheba Well-Known Member
    If there's a single dent in a steel print, and it's on an area that's differently textured from the rest, that's usually not a polishing issue, it's the scar where the infiltration stilt was cut off. Stilts, or sprues, are added to these prints in CAD, used in the part of the postprocess when bronze is added to the steel, and cut off by hand afterwards. Often the guys who are cutting them off are in a hurry, and they'll cut too far or not far enough or leave messy cut marks.

    This is an Ex One problem, and it really is a crapshoot. I complain when it happens, but I still get these, and I've been working with Ex One for 14 years. As far as I know, all service bureau steel printing on this planet is done by the same guys at the same factory, so it will be the same wherever you go.

    The cast metals, brass/bronze/silver/gold/platinum, are a completely different process. They too have sprues which are cut by hand in post, but it's a different factory with different guys, and they have more of a jewelry orientation. So I can't give you any optimistic thoughts about steel, but if cast metals are an option, understand that they are completely different from steel and will not suffer from the same problems. They'll have different problems.

    In closing, 3D printing is the worst and if you want good models you should carve them by hand with toothpicks. The end.
     
    Daphne_Lameris likes this.
  7. tinarity
    tinarity Well-Known Member
    Thank you for the enlightenment. I take it the lecture on the difficulties of 3D printing are free of charge. Unfortunately you completely missed the point.

    I will try to make myself a bit clearer in the hope that you might be able to follow my reasoning.

    As a customer I am actually not interested if the work staff is in a hurry, having a bad day or is plain incompetent. Pointing out, that the process is so difficult or your partnership with ExOne doesn’t doesn’t work so well, doesn’t help my issue either. (Besides it’s fairly poor company policy. My toothpick company doesn’t blame the trees or woodcutters if they come up with bad quality).

    I bought from SW and not ExOne. Where (and how) SW get it’s stuff done, is –again- not my business. My business is to get the service that’s been advertised. If it’s a well known fact, that steel prints are lousy, why offer them?

    Excuse me if I repeat myself, but you obviously didn’t get it: I am not going to print solid metal with SW because it might turn out to be just the same ordeal of reprints, complaints, ‘Sorrys’ and general frustration. I’ve already sunk enough money and time into steel prints.

    Besides the wax+cast enjoys a more lively competition and there are more companies out there eager to proof themselves.

    In closing I think 3D printing is great, I just don’t see it as a religion.
     
  8. Bathsheba
    Bathsheba Well-Known Member
    Yes, lectures are free. You certainly have my blessing to not buy printed steel, or anything else you want to not buy. Just thought you might find some interest or satisfaction in hearing that others have experienced similar problems, but it seems not.
     
  9. mkroeker
    mkroeker Well-Known Member
    The lady doth protest too much, methinks...
     
  10. MrNibbles
    MrNibbles Well-Known Member
    Like they say on the greeting page, Digitally Hand Crafted. While some of the goofs can arrive courtesy of the Digital side most will come from the Hand side. Not defending it but that's the nature of production on demand. Even a cheap overseas production factory will probably have more consistent quality production than what you will get with production on demand. In those cases even if they screw up the first 100 pieces once they come up to speed and know all the unique production issues the next 10,000 will probably be very similar.
     
  11. If you are not going to print metal from here why are you telling all of us? It is none of our business and while I welcome the information on the experience the multiple points as you put it become pointless. I too at times get models that do not print as designed, it happens. Shapeways reprints, or has it reprinted, and I get a new model. If it still doesn't work sometimes I just get a credit. I have a 3D printer so I also understand the complexity of the process. As you said your just the customer and do not care about the process or the workings. I am a customer, designer, model maker and supplier and I am not interested in your negativity or failure to understand the true issue behind your print.
     
  12. bengabel
    bengabel Active Member
    While the OP is clearly really unhappy and expressing things very critically, I think there's a valid point in this that we shouldn't ignore.
    The problem is partly conceptual, one doesn't expect so much human whimsy to be involved.
    I've had two issues with steel prints where it came down to a subjective choice by the operator who happened to end up dealing with my model.
    In the first case a model was rejected as 'cannot be stilted' , I tried again and it sailed through.
    In the second case, two previously successfully printed models arrived with a rougher slightly matte finish, they'd clearly been through a different polishing process than the other 3 in that order. I have 2 suggestions:
    SW should be more explicit about the amount of human intervention (stilting isn't mentioned anywhere) before you get your finished print. This will manage expectations better.
    And, SW could find a way of recording these human decision s against the model files. I _knew_ my model could be stilted because I was looking at the previous print and could see the scar. But clearly the person trying to stilt it didn't know this. That information needs to be loaded back from exone to SW so they're not figuring out out every time where on earth they can put the stilt (there were very few spots possible in that model) but instead just use the same place as last time. Or let us suggest stilt placement with a red patch on the model! Or whatever...
    Likewise, notes about finishing process chosen and whether it works or not need to be recorded, or well never get consistent prints. its about recording these subjective decisions and whether they worked.
    Especially if we're pushing the boundaries of the design guidelines to learn just what can be done with this technology.My models break the rules but I understand the process and design round that based on what I get back. But for this to work consistently there have to be consistent handling decisions noted against the models. It's no good if there is a way of successfully printing the model but whether this is done or not varies every time you print it...
     
    Last edited: Jul 21, 2016
  13. mkroeker
    mkroeker Well-Known Member
    On the material page for steel, under "Look and feel" is this:
    (Btw I see that the two possible finishing methods are now mentioned there as well, though they seem to stress model size as the determining factor).
    I suspect if the necessary infrastructure was put in place for the two companies to share detailed instructions and reports we would see a significant price increase as they then can no longer handle shapeways orders as it suits them. And from reading Bathsheba's contribution earlier in the thread it would appear that production of small, delicate jewelry in consumer-ready quality is not ExOne's core business anyway - engine blocks or pump casings anyone ?
     
  14. bengabel
    bengabel Active Member
    Yes, you're right and while technically it might be possible - probably it would be too hard to maintain, what with re-scaled models, variants etc.
    A better solution would be to be a bit more up front about the issue, and offer designers the option to sign up for a bit of extra control (like maker materials, or 'print it anyways');
    E.g:

    "Normally orientation, finishing and stilting is left to the discretion of our skilled engineers. If you are an experienced designer, understand the processes involved, and believe this particular model should be produced a particular way, you can make suggestions or override their choice.
    1) tick this box if your model surface map has marked in red areas you suggest for stilt placement"
    2) tick this box if you suggest the best polishing method is XXX or YYY"
    3) tick this box if you want the model processed the above way even if our engineers are dubious. In this case there will be no refunds."

    The only extra thing to make this work would be for the packing slip from ExOne to have on it "polished by method XXX" so you knew what they'd done the last time.
     
  15. jelloslug
    jelloslug Member
    I have had problems with parts that I have printed many times over and over and then all of a sudden they come in looking like crap and non functional. It obvious that they changed the part orientation from one print job to another and that is the difference between it working fine and not working at all.
     
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