Powder Appearing On Fud After Storage

Discussion in 'Finishing Techniques' started by Model_Monkey, Dec 5, 2016.

  1. MitchellJetten
    MitchellJetten Shapeways Employee CS Team
    To be honest I'm rather confused now.

    Because the bumpy white material (which used to be more transparent but is now more white due to the post process) is just the support material and has always been there and is, unfortunately, part of the printing process.

    Red being the model, gellow the support material (and thus after printing,, the bottom side of the model will have the rough surface)
    [​IMG]


    I think this is something different than Model Monkey was talking about
     
    Last edited: Mar 14, 2017
  2. 00dwkr
    00dwkr Member
    Hi Mitchell, thanks for your reply.

    Well, I see my problem as the same as what we have seen in the posts from Model Monkey and fbea458, and others. The illustrations in post #28 and post #55 are what I see on my purchases, but only on the 'undersurfaces'.

    So, help me understand.

    Maybe I'm misreading what you have said - but if I purchased an FUD sphere or globe, and that globe was 'printed' like in your excellent illustration, and the product is both the red and yellow, then half the globe (the upper) would be smooth, and half (the under) would be pebbled?

    But if I wanted a smooth upper and a smooth under, then, it would have to be printed as two half-pieces, that I could then glue together?

    So, if I purchased a little model airplane, made up of many different surfaces (upper and under, cylinders, etc), and it is 'printed' in one piece, then the FUD model will leave the factory with part of the outer surface FUD material (the uppers) and part wax with FUD below (the unders)?

    Sorry I am going on about this - but I have purchased some models from other suppliers, not Shapeways, that print in what looks like FUD, and the uppers and unders on those one-piece models are both smooth.

    Thanks for reading. Take care: Dan
     
  3. MitchellJetten
    MitchellJetten Shapeways Employee CS Team
    Yup, that's correct!

    The bottom side of the red sphere that is yellow is covered in wax support, after printing the wax is removed and you'll end up with a rough bottom.
    The top will be smooth (any part that isn't touched by support material).
    So to get both sides smooth you'll have to print them separately and glue them together.

    This is just the side effect of the Projet 35/3600 polyjet technique.

    Another example, tho with the colors switched around:
    upload_2017-3-14_11-47-3.png

    Everything red is support material which, when removed will get you a rough surface as it requires to support the yellow parts above it
    upload_2017-3-14_11-48-3.png
     
  4. stannum
    stannum Well-Known Member
    But why would crystal appear after painting? That is what some have shown and what is really troubling.
    [​IMG]
    [​IMG]
     
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  5. 00dwkr
    00dwkr Member
    Hi Mitchell: Thanks again for the illustrations. Now, I am sad.

    Because what I hear from reading what Mitchell wrote is that the train car sides are 'normal' FUD. Part of the sides are rough because they were supported, part are smooth because they were not supported. Mitchell, Correct? Thanks
     
  6. sapguy
    sapguy Member
    Yes, this is precisely what I was trying to point out earlier. Surfaces that were in shadow are going to have that textured surface, surfaces that were on the "up" side of the print bed will not. The parts, I've seen as examples were on the underside of (or next to) support material and thus the texture. If you have a spherical object and you want it smooth on all sides, cut it in two and rotate the underside to "up".
     
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  7. mkroeker
    mkroeker Well-Known Member
    Just another friendly reminder that this thread is about the phenomenon of "crystal growth" appearing on some initially smooth FUD/FXD parts after several days or weeks, not the roughness (of areas that were in contact with support wax) that is immediately apparent after cleaning and drying...
     
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  8. Model_Monkey
    Model_Monkey Well-Known Member
    Apparently the problem is not yet understood. Despite a good effort by SW customer service to determine the cause, the best that was offered to the customer who initially reported the problem was (paraphrased), "scrape off the crystallized surface and oil the part, then see what designers have to say about it on our forums".

    That recommendation just doesn't work on three levels.

    1. An oiled part can't be effectively painted.

    2. The solution treats the symptom but not the disease. It's like being told to scrape off the offending cancerous lesion and put some cream on it but no treatment for the cancer itself. No cause or solution has yet been offered regarding the cause and thus the prevention of detail-consuming crystallization growth on a part that develops some time after it has been received by the customer.

    3. Although not yet certain, the problem may be related to a material, chemical or printing issue, as was suggested by P2P 3D Printing (they claim this is a known problem caused by infrequent or insufficient printer cleaning). Designers are unlikely to be able to offer meaningful solutions to material, chemical or production issues, nor can designers examine production processes for possible causes.

    SW, please continue to investigate port-production crystallization growth.
     
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  9. sozzap23
    sozzap23 Member
    Agree Steve, the issue here isn't the slightly rough surface from where support material has been in contact with the part but the actual breakdown of the material itself. There seems to be some muddying of the waters on here about the real "crystallization' issue here.

    We've all had and seen enough parts to know how good the parts can be and that the support material isn't really the issue here. Of course it leaves a slightly different texture but nothing anywhere near the actual breakdown of material.

    I'm sure that by Mitchell's post he didn't mean actual breakdown of surfaces other wise the only surface we could print would be a flat oblong! (of course with a rough/crystallized underside). And if this was the case then Shapeways would of course be liable for mis selling of products as I don't recall seeing anything on the product description for FXD and FUD "this product will soon start to break down where ever there has been the waxy like support material, not ideal for printing your interesting (to you anyway, not really anyone else) character figures". Sorry, strayed into sarcastic waters there...

    Quoting the Shapeways product description: "Both materials utilize a waxy support material that is dissolved after printing is completed. Because the support material slightly changes the texture of the product, and isn’t applied to the entire product, you will see slight variability in texture over the surface of the model."

    Note: A slight variation in texture... not actual material breakdown.

    Also thought I'd post this too...

    fxd-train.jpg

    Looks gorgeous doesn't it? I can't see any breakdown or extreme roughness on this picture can you?
    Maybe it's a bit like ordering a Big Mac from McDonalds... looks great on the pictures but then the actual sodden lump of stodgy, limp bread with a bland anemic pattie arrives and leaves you feeling depressed and angry at the world.

    I'm sure Shapeways aren't trying to do the same here... are they?

    Solve the problem, don't cut corners and give the customer the product they think they're getting. Happy days for everyone. If not then a lot of Shapeways employees could be seeing a lot more of those Big Macs...

    Sorry for the sarcasm, but I'm a Brit so it's genetic and we don't like being taken for a ride.

    Simon
    Micro Master.
     
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  10. 00dwkr
    00dwkr Member
    Apologies if I wandered with my terminology.

    What I am seeing on my items is what is shown in Posts #7 and #22, after painting. My experience is that it only happened once (out of 12+ paintings) and not as 'bad' as the examples, only a few crystals.

    For unpainted, I have seen what was shown in Post #28. Crystallization.

    I just looked at some items I cleaned 2 to 4 weeks ago. All unpainted. The crystallization has advanced - I would estimate now covering 20 to 30% of the items, if it is averaged out.

    But, it is not really consistent - some items more, some items less. Two of the items are not bad (10%),
    but Steve's(Model Monkey) Los Angeles bridge is about 35% now.

    Frustrating.
     
  11. Model_Monkey
    Model_Monkey Well-Known Member
    I'm very concerned. SW, any ideas yet?
     
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