Scan Data Workflow for Pattern Creation and Manufacturing

Article by Rod Mackay updated November 25, 2016

Article

So you bought a scanner…you thought it would be easy to take scanned data and turn it into something useful without a lot of work. Maybe it isn’t as easy as the product demonstration you saw? The goal of this post is to help you with a scan data workflow for using your scanned data for downstream applications like pattern creation and CAM.

Scanner

Scanner

Scanning has so many positive attributes and shows the promise of why you bought it in the first place. The key to scanning is to be able to get the output you need without a lot of work. With this key point in mind, you need to consider the types of surfaces/objects you are scanning and the technology you are using.

Types of surfaces/objects you are scanning

For this article, I will consider the geometry to be scanned as the determining factor of the process and break it down into two distinct types of geometry:

1. Ornate, Organic Surfaces

This type of geometry requires technology that can easily capture very fine surfaces with abrupt changes. Typically, the data created has a very low tolerance to capture the detail, resulting in very large files that require specialized software to manipulate the dataset efficiently. Good examples of this would be a human face, or a highly detailed crystal flower vase, or similar items. Technologies used to capture this type of data would be laser scanning or light scanning technologies.

2. Flowing, Mathematical Surfaces

This type of geometry requires technology that can easily capture large, designed/manufactured surfaces with edges that are defined by the manufacturing process, (molded, stamped, sewn, formed, forged). Typically, the geometry created has tangent or curvature continuous surfaces that flow from one surface to the next. This data can be accurately represented by spline networks, (cross-sections) and classic surfacing techniques. This type of data collection can utilize very small data sets. Good examples of this would be a car fender, boat hull or an upholstered chair. Technologies used to capture this type of data would be single point digitizing or laser scanning or similar technologies.

Scan Data Workflow

The workflow for these two processes look like this:

Scanned Data Workflow

Scanning Workflow

Workflow for scanning Ornate and Organic Surfaces

The focus to get a usable output is on the scanning part of the process itself. As there is so much detail in the geometry, all effort is spent during the scan to make sure that this is captured. This can be quite time consuming based on the shape of the part itself.

The idea is to be able to take enough data that you can go directly to using the scanned data in downstream applications.

Workflow for scanning Flowing, Mathematical Surfaces

For this surface type, upfront knowledge is required when scanning to get only the data that is required. Understanding the reference data you need reduces how many data points to take and makes the job real easy!

This provides a couple of upside benefits:

  • Scanning time is much quicker: you don’t have to take so much data
  • Geometry creation is fast as you have exactly the data you need, you don’t have to figure out what you want to keep and what you want to discard,

Here is an example of a boat hull with different scan resolutions to show you what I mean:

To accurately capture the geometric shape of the scanned part, very little data is needed. Capturing the outline and defining contours (cross-sections) that can accurately describe the part’s shape is all that is required.

This scan was done in a similar fashion to what a laser scanner would produce. Lots of data over the entire part.

Filtering points

Having a quick filtering tool to reduce the amount of data down to what you need is a critical part of the process. The above example Scan A has 8714 points, Scan B has 870!

Processing time to bring in Scan B is 3 seconds!

The process to bring in these raw data points is very simple. The data is in a human-readable, flat ASCII format that can be viewed in Notepad or Excel. Here is what the data looks like:

Scanned Data

Scanned Data

Scan workflow example

In this example, here is what the workflow looks like to import the scanned data into SOLIDWORKS with ExactFlat:

Scan Process

Scan Process

Finally, after about 3 minutes of work converting the data to a surface model, the finished part is ready to go in SOLIDWORKS!

Scanned model in SOLIDWORKS

Scanned model in SOLIDWORKS

For parts with symmetry, scanning time is cut in half as only half the part needs to be scanned and modeled. Below is a great example of a car seat utilizing the same process as above incorporating symmetry to cut scanning and modeling time down by as much as 50%!

Car seat scanned data

Car seat scanned data

Critical factors to consider when scanning

Scanning can be a great way to capture parts digitally that need to have replacement parts manufactured, engineering changes made, or entire new designs created. Utilizing the technology and understanding the key driving parameters for what types of scanning you need to do are important to the success of your project!

 

  • Understand your project based on geometry detail
  • Map out the data you want to acquire, use masking tape/guides to get the correct sectional data.

If you already have a scanner, you have just about everything you need to get started.

The Scan Data Workflow described above was put in place to create flat patterns of complex geometry that typically takes a long time to develop using manual methods. Scanning is a key part of this process as you need to have the data first before you can create the patterns. Look out for my next post on creating the flat pattern within SOLIDWORKS.

Conclusion

I hope you found this post helpful for understanding the basics for creating an efficient workflow to use scanned data to create usable geometry for an engineering application. Sometimes there are gaps between adjacent technologies that need to be bridged before a workflow can become very efficient.

To learn more view our recent ExactFlat on-demand webinars in our blog or visit our ExactFlat product page.

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Rod Mackay

Rod has been using 3D CAD software for over 25 years and has trained thousands of designers to use their CAD systems more effectively. Rod is the Javelin Webmaster and is based in Ottawa, ON., Canada.