In this article, I will describe 3 benefits of ANSYS SpaceClaim Direct Modeler for 3D Printing and other applications. Specifically I will focus my attention on the Facet Tool in this article.
While searching for freely-available CAD models on GrabCAD.com, I chanced upon the challenges section because it piqued my interest. To my surprise, I found about 75% of the recent challenges to be related to topology optimization. For most of these challenges, lightweighting will yield a final design output that is optimum in weight. However such an output will be complex for traditional manufacturing processes. In the recent years, additive manufacturing or, often referred to as, 3D printing has appeared to be the manufacturing process of choice for several contemporary applications.
For topology optimization, ANSYS is the simulation tool of choice. In the latest Release 18, a significant thrust was provided to this topic. The technology is very powerful and highly-effective for lightweighting the designs. Typically, topology optimization results in the design in STL file format. In my experience, this design output is often fraught with poor facet quality and this requires cleanup by a competent tool.
The full suite of ANSYS Simulation Software offers not just solvers for multiple physics, but also several value added tools such as ANSYS SpaceClaim Direct Modeler (SCDM). This tool allows product companies to launch their offerings faster to market.
Now SCDM has several useful features that allow geometry manipulation and clean-up. Among many features, I found the Facet Tool to be extremely useful. After completion of topology optimization, the STL file output from ANSYS is imported into SCDM. This Facet Tool helps in cleaning up the STL file output containing poor facet quality and helps me prepare the design for validation using ANSYS Mechanical.
For better understanding, I have included the typical workflow below.
With this context in place, I will now introduce you to the 3 significant benefits of using ANSYS SpaceClaim Direct Modeler for 3D Printing applications.
HIPP Add-In for Reverse Engineering
HIPP is an SCDM add-in developed by ReverseEngineering.com. This tool is quite useful for engineers performing reverse engineering – with the eventual goal of producing the desired part using 3D Printing. For this case, the approach typically starts with scanning of the part desired for reverse engineering. The scan results in an STL file format created directly in SCDM; this automatic scan to STL is powered by the HIPP add-in. The Facet Tool in SCDM is then used to repair and prepare a watertight geometry.
Here’s an example of the scanned geometry of top profile of a piston rod that was generated in SCDM using the HIPP add-in. The facets in this geometry did not capture the profile accurately. Furthermore the geometry has undesired holes along with unwanted parts.
Using the Facet Tool, the repaired geometry is now ready for topology optimization and design validation before producing it using 3D Printing.
Save Resources – Faster to Market
There are numerous software tools for STL preparation, however SCDM Facet Tool has many value-adding, additional capabilities. With a very little investment, the Facet Tool provides a strong hold in combining multiple solid parts with faceted geometries in a user-friendly manner; this feature has several advantageous implications for 3D printing. Furthermore the tool is very easy and requires little knowledge for geometry repair and preparation. To prepare the bracket geometry (illustrated at the beginning of the article), it took me 10-15 minutes. See the below image. Now I found it to be fairly quick when compared to 2-3 times more using other facet modeling tools.
Preventing Failures in 3D Printing
The Facet Tool has features to detect thickness and overhang problems before the model is sent for 3D Printing. Now these overhangs present a challenge to 3D printing without using support material. Problems such as these can be prevented by few techniques like tear-dropping, tapering among others. The effects of overhang cannot be judged immediately until you are a 3D Printing professional.
Facet Tool has a feature which detects the overhangs by providing parameters specific to 3D Printing. In particular, the thickness feature detects all geometry that is thinner than the minimum thickness specified by the printer OEM. In addition, I could understand thickness and overhangs-related problems beforehand by providing the direction of printing as well.
This topic is also of CADFEM’s particular interest because we invest into Digital Cities – a strategic initiative of CADFEM International that aims to simulate cities of our future. This topic is quite special and important since it involves studying the effects of disaster scenarios such as earthquake, tsunamis, pollution, crowd behavior among others.
virtualcitySYSTEMS, a CADFEM International group company, develops 3D city models using scanned data of terrains. For these city models, we use the Facet Tool to repair the geometry before performing urban simulations.
In future posts, I will delve further into using CFD and particle simulations for better modeling of 3D Printing applications.