Tips for Preparing STL File for Architectural 3d Print Model?

A finishing well prepare 3d printed architecture model with clean and smooth appearance / Photo credit by Prozix.com

Preparing an STL file for architectural model can be very frustrating since most architecture models that require 3d printing are often intricate and complex design, so If you have knew and doing the preparation for 3d print your model ahead would definitely makes the printing process much easier and the model would get the best result it possibly can. Here are a few tips from me from experienced of 3 years of design architecture project for 3d printing for educational presentation and have done hundred of printing projects for architecture students and local architecture firm.

1. Always make sure your model is Solid aka water-tight!

This model shows many naked edge on the bottom, where the model was sliced without closing / Photo credit by Prozix.com

It is the most important for every 3d print project because if it is not solid, it is non-printable. Therefore, make sure it is water-tight before you export it to STL.

  • Make sure to track the model status often after you execute an milstone command – I use Rhino and I always track if my model is Closed Polysurface after command such as Boolean Union or Boolean Split because as you go on to more complex design, your model could easily because Open Polysurface due to Rhino tolerance
  • If you have no choice because there is no time for you to redo your model with too much trouble of open polysurface, try to use free tool to fix it such as  Nettfabb  , it is very powerful and easy to use.
  • If nothing has work out with your too much trouble files, you can try to contact some 3d printing expert because they may have Nettfabb Pro or they would examine your file to figure out where you need to fix. Sometime, a non-watertight model can also be print with acceptable lower quality.

2. Make sure the wall thickness  meets the minimum requirement.

The back of the wall was too thin to print in horizontal direction/ Photo credit by Prozix.com

Most architecture model will be done with Plastic type printer aka FDM printing technology for more affordable prototyping and larger model scale. Here is a few things you need to consider for the wall thickness:

  • The minimum wall thickness is generally 1-2 mm depend on the condition of the walls – straight or curve ext..- but generally a thickness of 1/16″ will work just fine for most of the time.
  • If you model need lot of supporting to print ( overhang of 45 degree or greater will require supporting ) you may consider cheating the actual thickness to make it thicker, so it will be easier to deal with the rough surface later on such as sanding or acetone smooth vapor.
  • If there is an embossed and engraved details in your model, make sure it need at least 2mm to be visible when print.

3. Always design to print without supporting as priority for best quality.

Building without roof get the perfectly fine details/Photo credit by Prozix.com

I know design to print without support for architecture model is near impossible “If” you want to print your whole model as one print. It is only possible for site models ( block building ) with no details or intricate interior. However, there are many ways to print your architecture model with minimal supporting require ( supporting always leave rough texture finishing for FDM 3d print regardless of how well the printer was  setting). Water Soluble material may help, but it is not always the option, so the best choice is to design a printer friendly model with the following tips:

  • If it is a building, always try to separate the roof and the walls to have them print separately and glue it back when it finish. It usually leave no trace of glueing in a clean joint. It is very important for two reasons: it will be much cheaper to not print tons of supporting to support the roof, and it is not always possible to remove the interior support without breaking anything specially when your model is 1/16 scale with small window.
  • If your model has more than one story, you should separate the floor at wells. the key is to print the horizontal plates and vertical element such as walls or column separate to avoid the 45 degree overhang.
  • If your model involve lot of intricate curved or irregular shape that have lot of overhang or details. Try to figure out the best possible place to split your model so it will have at least 1 side cut flat and less overhang.

Conclusion:

Making a successful 3d print model require lot of understanding of how the printer works, so the designer can make decision on what to do, sometime making a couple split lines will make the model appear to be clean and perfect once you carefully glue it with back with maxi-cure, sometime having supporting is not a problem if the area is not meant to be seen, sometime using water solute material for support is best ( it can be expensive ). It is most of the time case by case basic when it come to a very complex design that require lots of attention to details.

P/s: Contact a 3d printing expert for help is always the key, even before you start to draw your first line in your 3d modeling software.

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