How To Make 3D STL Models For A CNC Router? | The Edge Cutter

Don't miss any deals or latest information on woodworking and CNC. Join us on our Facebook too.

Making 3D models for CNC routers is nothing exceptional compared to the model files prepared for other relevant purposes, like  animation, 3D printing, or so. In fact, CNC machining software is way more easy going than 3D printers as CNC machines do not  build an object from scratch but machines the outer surfaces of the project as per the input design.

Now, before checking on how to prepare 3D STL models for CNC routing, let’s first understand what STL means. 

STL Files

STL, that is STereoLithography or Standard Triangle Language is a type of  file format to save a 3D model. The concept of STL file format started a long time back as a default standard for using in 3D printing processes. This, over time, became a useful method of  exchanging 3D objects among all types of programs.

An STL file supports an entire object representation, including all its sides and surfaces along with its internal features. Though this type of file format is better suited for 3D printing purposes that include internal structuring of the model, a CNC router can also utilize these files to machine the outer side of the workpiece. 

An STL file represents the basic 3D model as a triangular series, despite the original design having been developed by a high-end CAD program, like Autodesk Fusion 360, Solidworks, or so.  

Some users believe that this leads to reduced accuracy in the product output since the sequence of triangles cannot entirely and precisely represent the model. However, this conception is not true for the following cases:  

  • A 3D STL model can be created to some random accuracy which can be more accurate compared to the output you get through CNC machining.  
  • Almost every modern CAM software converts a CAD-generated design into a sequence of triangles before preparing the toolpath. Otherwise, the process would be error-prone if not considered the triangles.
  • Certain 3D STL model files create innumerable triangles by taking its  count to the extreme limit. This can result in a long tool-path time calculation, higher memory usage, thereby leading to a poor final product. In practical terms, the triangle count of 250,000 is sufficiently workable to yield a better end product through CNC routing.

How to make a 3D STL model from scratch?

Designing a 3D STL model is a huge topic to cover but here are some of the useful points you can begin with:  

  • Firstly you will need 3D CAD/CAM software programs for creating reliefs. For instance, both Vectric Aspire and Carbide Create Pro help you to design 3D relief models right from the scratch by following a simplified workflow in comparison to the full-fledged 3D CAD programs like Solidworks or Alibre. These software programs are typically meant to create 3D models for CNC machines. All in all, if you are targeting a CNC router to realize your 3D STL model, then the above mentioned CAD/CAM programs fit the best.  
  • Conversely, both Alibre and Solidworks are known for their high-end advanced 3D CAD programs that let you create  models of almost any object, that too, with high accuracy and  high-level control. Alibre is an affordably priced program, considering the capabilities it comes along with. Solidworks, on the other hand, is quite expensive, however, has a greater preference in the industrial zone.

The Edge Cutter is reader-supported website. When you buy through links on our website, we may earn an affiliate commission.

Leave a Comment