WSF and the Material Pages

Discussion in 'General Discussion' started by noc146, May 1, 2012.

  1. noc146
    noc146 Member
    I see an update on the Official Announcements regarding WSF and possible print lines. This of course is down to the variations in print orientation, which many modellers here would wish to be able to specify precisely, at a nominal premium cost.

    On the Material Pages, it states that 'You can usually get rid of these lines with light sanding with sandpaper.'

    This is an unfair and misleading statement. On numerous models I have ordered, myself and others have tried with enormous difficulty to make any impression at all on these print lines. I myself have used every grade of sandpaper, and have even tried a heavy grade metal file. I have rubbed and rubbed and rubbed till my arm ached, and I have made no discernible difference at all. It was for this very reason, I had to remove my entire range of models from availability from my shop.

    WSF is a very hardwearing and durable material. That is an enormous advantage of this material, in many ways. But it simply does not sand easily. If it sanded so easily, then there would be no need to argue for specified printing orientation, which is badly needed in order to guarantee any kind of quality using this material.

    It is vitally important that the material specifications are clear about this. It may be possible to use some brand of filling putty over the lines, and sand that down. But that is different than stating the lines can usually be removed with light sanding.

    I wonder can Shapeways make this clear on the Material page. The durability and strength of WSF is a great feature. But it does not sand easily at all. That is a simple fact about the material.
     
    Last edited: May 1, 2012
  2. GWMT
    GWMT Active Member
    WSF sands easily only if you heavily paint it then sand it (preferably with a Dremel tool). That way you're mostly sanding off paint from the high spots.

    https://www.shapeways.com/forum/index.php?t=msg&th=4840&a mp;start=0&

    Have you tried printing a bus in Frosted Detail yet? FD is easy to sand once you paint it and can see what needs sanding; the ridges are about 0.002" high. You need to sand everything, though:
    THB 2600 gon side partly sanded_0061.jpg
     
  3. noc146
    noc146 Member
    Sanding the paint off, yes, though the material itself is hard to sand. I just thought it would be worth pointing this out on the Material page, rather than stating erroneously that WSF is easy to sand.

    As for FUD, I did get some buses printed in that material, at a much dearer cost than WSF, and they were a disaster. A mish-mash of clear and rough finish, and covered in some foul yellow wax that I still haven't managed to clean off properly. Even if I do manage to clean it all off, there is no way I could sell anything of that poor quality to anyone else. They were unfit even to show anyone.

    In this and other posts, I suppose I am trying to make the point that just because Shapeways is opening up 3D printing to the masses, at affordable prices, it is not a justification for poor quality. Unfortunately, most of what I and my customers have ordered over the last year has been of dubious quality for one reason or another. I need to be able to rely on a standard level of quality, rather than the lottery I have had up to now.

    The very first print I got was very good. In fact I was delighted with it. Most prints since have been invariably worse, either orientated wrongly, not cleaned properly, delivered with broken parts due to being jammed into unsuitable packaging, one part even appeared to have shifted in the machine due to wavy print lines, and with regard to FUD, that horrible wax.

    If I were to send back every unsuitable print to Shapeways, I would have sent back most of them. Instead, I have absorbed the cost of them, and made the best of them. It's part of a learning process. I didn't mind in the beginning. But I am getting tired of it. This doesn't lend itself to opening a shop and selling such models in any numbers to other unsuspecting customers. I have already taken much criticism over the few I have sold.

    I'd love to push Shapeways among my modelling community here, but so far, the results have not been reliable enough. At the moment, it really only serves for my own private models, and there are other better quality manufacturers for that.
     
    Last edited: May 1, 2012
  4. noc146
    noc146 Member
    Let me just qualify this:

    I expect 3D prints to have print lines. That goes without saying. I just ask as politely as possible that at some time in the future we might be allowed orientate our models to minimise the effects of print lines. It would allow me to offer my models for sale again.

    Apologies for being a bore, onwards and upwards...
     
    Last edited: May 1, 2012
  5. BillBedford
    BillBedford Member
    How would that help? You would just get the same lines on a different face.

     
  6. stannum
    stannum Well-Known Member
    You would pick which zone is the rough one. And with some thinking, it would be something that is easy to fix, or even hidden away. Easy approach: design everything thinking in term of flat gravity moulds (or one half of two part plastic injection), then you get the good surface with best detail, and the other would not matter as it would be glued back to back.
     
  7. stonysmith
    stonysmith Well-Known Member Moderator
    There is a liquid called BESTINE which is available here in the US thru Michaels Craft Stores. It cuts thru the support material wax very quickly, and it leaves the FUD model with an opaque white finis that seems to hold paint better than the raw surface.

    One warning: it's a very "aromatic" liquid.. it should not be used indoors without ventilation.
     
  8. GWMT
    GWMT Active Member
    Hi Bunrattypark;

    Shapeways doesn't use that yellow stuff anymore; the current FD/FUD support material cleans up easily with no after effects. You'll like it now.

    I feel the same way about the random quality of what we get from Shapeways; if they ever offer us the option to specify the print orientation a lot of the problems will go away. Now I find prints that previously arrived in one piece are showing up with parts broken off; I think it's partly from too many pieces being placed in one container going from the printer to Shapeways (so prints on the bottom get crushed) and occasionally from insufficient packaging when they are packed for final shipment. The damage is random; you can't predict what will happen.

    What other print companies are you using? I priced some stuff with ZoomRP in Polyjet HD Blue ( https://www.zoomrp.com/polyjet-printer.aspx ); they're twice as much as Shapeways. I'm looking forward to seeing what results Jeff gets from them:

    https://www.shapeways.com/forum/index.php?t=msg&th=9172&a mp;start=0&

    I've talked with a lot of potential customers about what can be printed and what might go wrong with an order; almost every one said they would not order prints if they couldn't be certain they'd get a decent print the first time. I hope Shapeways will set up a second printing channel that allows us to specify the print orientation and handles the prints with more care (and charge us more money for superior service). Once the uncertainty gets ironed out of the system things will really take off.
     
  9. Bathsheba
    Bathsheba Well-Known Member
    Orientation matters, IMO it's worth asking for the feature.

    Then again I can see why Shapeways doesn't want to leap into it -- it's one more thing to fiddle with and make mistakes with, and people who don't have much experience with 3DP may not use it wisely. It's not hard to think of cases where specifying orientation wouldn't do the user much good, but would make the model more expensive and/or harder to build.

    Maybe it would work best if users are encouraged not to check the "enforce orientation" box unless they can state clearly why they want to....
     
  10. ZoeBrain
    ZoeBrain Member
    Technique used:

    1. Use a fine-grain metal file. This rids the surface of the artefacts, leaving just a horribly grooved surface. Use a rats-tail file to add some curves if need be.

    2. Use an emery board backed with a metal file to make it less rough. First coarse, then fine. This takes a loooooonnnggg time.

    3. Use Aeromodelling fine-grain filling putty to cover the surface as thinly as you can.

    Then use a flat-bladed craft knife to scrape most off.

    4. Paint PVA glue on. Wait one day till dry

    5. Repeat sanding with fine emery board. This leaves a finish a lot smoother than unpolished WSF. The putty/PVA mix fills the gaps in the WSF surface quite nicely.

    6. Paint with gloss varnish. This will make the surface glassy smooth.

    Steps 1 & 2 can be omitted if there are no flaws. Step 2 takes up more time than the rest put together, we're talking several hours for 3-4 cm squared.


    "Easy" it isn't. Sandpaper won't do the job. It's one of the most difficult materials possible to sand. "Light sanding" is useless, you need a metal file, then putty to fill the resultant tool marks.
     
    Last edited: May 3, 2012
  11. BillBedford
    BillBedford Member
    1/ Use wet & dry paper in a split shank in a dremel/pendant motor. Coarse abrasive will mark the surface so I would recommend 320grit or finer.

    2/ The nylon can be polished with a dry hard felt wheel again in a dremel/pendant motor.

    Both of these techniques are best for continuous surfaces. Surfaces with sharp details can be smoothed by scraping with a sharp curved scalpel blade. Work with rather than across the 'grain'.
     
  12. 65166_deleted
    65166_deleted Member
    Hey guys,

    Print orientation specification is definitely in the consideration of features to add here. Quick question, what would you be willing to pay for this service?

    Thanks
     
  13. stop4stuff
    stop4stuff Well-Known Member
    Bing!

    With the volume of orders you guys have, is there not enough orders to be able to cope with n amount X axis, Z axis & Y axis orientations plus those that don't mind to be able to just have a check box that allocates the orders in a similar way to how orders are handled now for different materials - if you like, WSF splits to 4 material types depending upon the designers' allocation of orientation?

     
  14. 65166_deleted
    65166_deleted Member
    Paul, can you explain what you mean? I started to answer your question and then realized I don't actually understand what you are proposing.

    Thanks
     
  15. stop4stuff
    stop4stuff Well-Known Member
    WSF 1 = X up
    WSF 2 = Y up
    WSF 3 = Z up
    WSF 4 = don't care which way up is

    I don't know how models are arranged for a print run, but I'm taking an educated guess that software optimises the model packing for a certain total volume/bounding box that can be printed in one hit. So, the software just needs a little tweak to account for orientation preferences to allocate the model to whichever print run is best suited i.e. WSF 1 + 4, WSF 2 +4 or WSF 3 + 4. Obviously this could not work out if the total amount of orders do not reach the required optimisation needed.

     
  16. GWMT
    GWMT Active Member
    Rather than four different orientation options how about just two: Fixed Orientation (with Z axis up) and No Preferred Orientation. It will be up to the designer to make sure their part's oriented correctly before they upload it.

    Nancy - see if 1.5 to 1.8 times the current cost of materials for fixed orientation works; 2 times the cost of FD/FUD (that's about what ZoomRP quotes) seems just a little too high to me.

    Shapeways' greatest strength is the storefront that allows potential customers to order prints directly with no work required by the designer. I can add a few bucks in profit to the part's cost and still make money while keeping the customer's price reasonable.

    If I order from another service I need to add the cost of shipping and duty to the final price plus the cost of my time repackaging the print for shipment to the customer; most things will be too expensive to sell with all those added costs.
     
  17. stop4stuff
    stop4stuff Well-Known Member
    Good call!

    I did think about just the two options, but remembered that with the software I use (Imagine) I have to have my model orientated as upsidedown in the Y axis to show as 'upright' in Shapeways preview render, so I figured other software varies too. For this to work the model preview needs to be fixed for updated models (currently the preview render does not get updated if a model is updated)
     
  18. stonysmith
    stonysmith Well-Known Member Moderator
    I would think "Z up" would be simple enough.. the let the user adjust their orientation until the Shapeways Render is oriented properly.