Design Guidelines For 3D Printed Structures – Your Full Guide

When designing models for 3D printing, there is a vast range of design guidelines you need to keep in mind to be able to print your project successfully. This article will highlight some crucial design guidelines you must look out for.

Just like any other type of manufacturing, 3D printing also has certain limitations to the manufacturing process and materials that command how you must design a product. Characteristics of software, hardware, filament, and temperature among other factors play a crucial role in how the digital model translates into a 3D printed object.

To understand all about 3D print houses construction, you may review the following Can I Build My Own 3D Printed House? Hidden Costs & Prices of Construction 3D Printers !, How Tall Can You Build a 3D Printed House?, and Do 3D Printed Houses Use Rebar?, and How Are 3D Printed Houses Durable Without Steel Reinforcement?

Design a Strong Base

When using a desktop 3D printer, the model is printed in layers one at a time. The plastic filament (ABS or PLA) is melted and melted, then extruded into the printer bed surface. It is critical that the first layer sticks to the bed during the printing process. In case the model loses adhesion in the process of printing period, the game is over. Prints will often fail during the first layer because of a lack of adhesion.

3D Printing Is Here To Stay

More fine-tuning must be done to the printing software and 3D printer in order to print the first layer successfully. You need to ‘’level the bed”, physically using adjustment screws to ensure the extruder is positioned perfectly parallel with the bed surface. You can also add a raft or brim in the software, increase the thickness of the first layer extrusion, and turn off the fast layer fans.

Furthermore, you can have your 3D printer configured perfectly, but this will not help you if your model is not well-designed to stick to the bed and support itself during the printing process. You must ensure that you have a strong base in your model, designed with the following characteristics:

  • Wide enough to resist tipping over and support the model during the printing process
  • Enough surface area to enhance positive adhesion to your printer bed. You can add a raft to your 3D printing software to help with this.
  • Strong enough to enable them to resist wrapping, mostly caused by different cooling rates. 
  • Grain direction

3D printed objects must have a grain direction since every layer is extruded a layer at a time. Every layer is stuck to the next, and joints between the layers are vulnerable to delamination. In case your models are designed for structural applications, the layer joints may become weak points in your models should you fail to orient them correctly.

To overcome this probable problem, it is advisable to orient your model such that the X/Y axis plane in the model is positioned where you need the most strength. Continuous extrusion takes place along the X/Y axis plane, making them stronger.

Holes/Overhangs For 3D Print Designs

Since each layer rests on the next one, there are higher chances that your 3D print will fail if you have parts of your model supported by thin air. Most 3D printing software has the capacity to automatically add support material to your 3D model that can be easily broken down once the printing process is completed. However, many gaps can be bridged by a 3D printer without the need for support material. Most small holes can print well. Also, anything less than 45 degrees overhang can as well printed without the need for automated supported material.

Wall Thickness For 3D Print Designs

When importing your model into the 3D printing software, you have the ability to control most variables, including the wall thickness of your model. The wall thickness outlines the number of times the 3D printer extruder will spread filament around your model’s perimeter before switching back to your infill factor, (typically 10 or 20 percent).

Your 3D printer nozzle diameter should basically define your model wall thickness. Therefore, a 4 mm nozzle with an 8 mm wall thickness may result in the 3D printer laying a 2 mm width perimeter thickness for each layer.

It is vital to keep this aspect in mind when drawing thin walls. When your model parts are thin, the perimeter walls also get closer together, leaving not much room for infill between them. At times, it may not fuse the walls properly to each other, leaving hollow gaps between the walls viewed from inside your model.  

  • Rounded corners

SketchUp is great when making objects with square edges and flat faces using the Pull/Push tool. It becomes tricky to round off corners. However, round corners are stronger from a structural point of view. Round corners will also cause less wear and tear on your 3D printer since changes in direction are much more gradual than sudden.

  • Tolerances

In case, you are designing 3D parts that must fit one another, you should take the tolerance factor into consideration. For instance, a 10 mm peg will never fit into a 10 mm hole. The hole must be slightly larger.

Segmentation of the curves in the SketchUp model is another factor that comes into play. Softened/Smoothened edges are irrelevant the moment you export your 3D model to STL

  • Consider increasing the segments on your curves in an effort to make your model smoother.
  • Ensure segmented curves are well aligned with each other in cases where they should fit together.
  • Leave enough clearance to allow the 3D parts to fit.
  • Mock-ups 

When designing 3D parts with critical tolerances, try and isolate those parts of your model and consider printing them out separately. This will enable you to test fit that part separately, without having to worry about the rest of your model.  Once you confirm that the parts are correct after a series of iterations, you can then incorporate all the shapes back into your main model.

Unique Properties

You are not limited to designing a solid, rigid object. You need to experiment with the exclusive properties of the 3D printer and material to exploit their characteristics.

Check your GCode

The GCode is simply a set of computer instructions generated to guide your 3D printer on how to print your 3D model step by step. When getting ready to carry our 3D printing, it is advisable that you take a look at the visualization of the GCode, before you send it to your 3D printer. A visualization will clearly show what your 3D model will look like when printed by your 3D printer.

There are quite a lot of things that can go south with a 3D model. For instance, if the model is not solid, and you fail to rectify the mistake, taking a look at your GCode visualization remains your last option to catch anything before getting to the 3D printer.

Most 3D printing software comes with an inbuilt visualizer. However, if yours does not have, you can get it through your browser at link. Some things you can be able to catch from visualization include:

  • You may see a generated support material and resolve to make changes to your model in order to reduce the amount of material required.
  • You may realize that your infill was set too high.
  • You may realize that you did not have a raft when you thought you had checked this option.
  • You may notice major errors caused by your model not being solid.
  • You may realize the model is not sitting flat on the printer bed, because you had accidentally rotated your model a few degrees.

PS: To know how much time is needed to build a 3D Printed house, check out How long does it take to 3D print a house?

Why We Need a Design Code

Design coding is very crucial in 3D printing technology. Programming the 3D printer and 3D graphics programming are two crucial design codes that make the most out of 3D printing technology. Graphics coding enables the creation of advanced 3D objects based on realistic solids. You need not be an artist, simply get the hang of design code and know all you need for your 3D model.

3D graphics requires a bit of artistic creativity. It is the work of interior designers, and architects, among other experts that carry out modeling. However, computer-generated 3D graphics requires coding the 3D models by editing scripts and not drawing using 3D design software such as OpenSCAD.

G-CodeL is another coding language used to transform 3D models into instructions easily understood by 3D printers. The coded language can be mastered to help modify the 3D printout parameters by operating on the code.

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