Facade Model in White, Strong & Flexible

Discussion in 'My Work In Progress' started by PotterAndrew, Nov 15, 2012.

  1. PotterAndrew
    PotterAndrew New Member
    Hello All,

    -I'm currently working on an architecture model to be presented in a gallery in a few months. I'm trying to figure out if the 3D printing of the facade will be a viable option for the project.

    -The dimensions of the model are 133.5 cm long, 53 cm wide, and 18 cm high. The thickness of the facade is 5 mm to scale. This thickness can change to become a hollow object or thinner to fit the printing standards so that it will not warp or break. I was suggested to make the facade 2mm thick. I'm wondering which option will be easier (diagram included). Option 1 in which we print a solid 2mm surface then go back and manually model the portion behind? Or if option 2 is a possibility in which the back and front facades are 1mm thick and has some type of waffle system in between them for support? I really need the facade to be as flat and accurate as possible.

    - The facade is a stone texture, so we are looking to get a rough appearance vs a flat plane. I can certainly model in the texture of a
    roughness but what level of depth or thickness will the texture need for it to be picked up in the white strong and flexible.

    - We have areas of the facade that are recessed back in between bricks. Will the thickness of recessed areas always need to be at least .7mm or
    can some areas get thinner?

    I have attached some images showing the facade and the details that we are looking to acheive.

    Thanks for your help!


     

    Attached Files:

  2. PotterAndrew
    PotterAndrew New Member
    Image of the overall facade
     

    Attached Files:

  3. Piers
    Piers New Member
    Hello Andrew

    Its quite hard to tell from the front elevation alone. But i would personally choose the manual finishing.

    As for the material/process:
    Strong and flexible Plastic' (SLS) could get a little tricky because of this :

    For example, say that your part is x mm long (longest dimension). If x < 117mm, then the min wall should be 0.7mm to prevent bad warping. If x > 117mm, then for each mm above 117, you should add 0.006mm to the 0.7mm. In other words, try to maintain around a 1 to 166 ratio between your longest dimension and your minimum wall thickness.

    Your minimum wall thickness needs to be around 2.5mm, i think .....i have never been to good at calculating that
    Alternatively, you could print the facade in sections, To avoid nasty vertical join marks use the thin diagonal detail as your split line.
    Although one of the cheapest / strongest (plastic) forms of 3d printing 'Strong and flexible Plastic' lacks the surface finish of SLA , so may not be good enough as a display piece. The chances that the texture will match the scale is a bit risky. But could look amazing if it works.

    Then there is 'Fine Detail' (SLA, or something with an acrylic photo-polymer) your other option.
    This is the process I would recommend. I have a friend who produces architectural models using a similar process. You would most likely have to do the facade in sections with this one, as bed sizes are generally smaller. The Acrylic based photo-polymer can be sanded, glued, cut, etc alot easier than SLS' Nylon. For the texture, the polymers take cellulose paint well and depending on your facilities you could simply spray a fine spark/speckle.
    But...... its alot more expensive...... oh and brittle but 2mm is plenty thick for gentle hands.

    BTW I used to be an architectural modelmaker, id be interested in seeing how it comes out. If you print it could you please post some images.

    I believe Shapeways automated model checking robot thing will detect the below 0.7 thickness and automatically reject it.

    Hope that helps
    Piers
     
    Last edited: Nov 15, 2012
  4. stonysmith
    stonysmith Well-Known Member Moderator
    I would suggest you make a couple of test prints. The Sandstone material should do well for you and it's cheaper than any of the plastics.
    The trouble is .. that's a HUGE model.. it's going to be rather expensive!

    http://stonysmith.com/wired/VolumeEstimator.asp?L=1330&W =530&H=180&T=2
     
  5. PotterAndrew
    PotterAndrew New Member
    Hi Piers,

    Thanks for your response!

    Your input was very helpful in making a test print to try out the scale and texture. Unfortunately we do not have an unlimited budget for the project so I am unsure if we will be able to afford the "Fine Detail" over the "White, Strong and Flexible".

    As soon as I get the test printed I will be sure to post some images.

    Thanks again,
    Andrew
     
  6. PotterAndrew
    PotterAndrew New Member
    I had a question on the estimator on your website.

    We planned on getting the facade printed in a series of sections, so they could be nested together in the printing bed easier.

    I am working in Rhino and when I calculate the volume of a wall that is 400 x 3 x 175 with a wall thickness of 3 I get a volume of 210 cm3,
    and when I use the shapeways price estimator I get a total volume of 413.17cm3.

    When shapeways price things by volume is it the actual objects volume that is being 3d printed or a volume including some other portion of material used?
     
  7. Piers
    Piers New Member
    No worries hope it goes well.

    Piers