Need for Speed: Tips for Faster Scanning

– David O’ConnorDavid O'Connor Shapegrabber

Already capturing tens of thousands of data points per second and still want to go faster? Data acquisition using a Shapegrabber system is already lightning fast compared to traditional tools like CMMs and hand tools. However, if you are scanning hundreds of parts a day, seconds–per-part start to add up. This article covers four areas you can tweak and tune if you are looking to increase throughput with your Shapegrabber scanner.

1. Scan Resolution

First, consider the scan resolution you are using to scan parts. The spacing between lines in the scanning direction (Y-axis resolution) directly affects the scanning speed: twice the resolution means twice the scan time. While a very fine resolution is useful for capturing small defects, you may be able to back off the resolution for speed gains if the goal is to characterize overall shape.

Finding the optimal setting to maximize speed while ensuring defects are still detected may take some experimentation. Begin with a sample that has a known defect and try increasing the Y-axis resolution value until that defect is no longer obvious in the analysis. You may be surprised how much faster the scanning can be.

2. Number of Scans

Next, consider the total number of scans. It is easy to set a Shapegrabber scanner to automatically capture many scans in order to obtain lots of detail on a part. But, spending some additional time up front to determine which scan angles are essential for an application and which ones can be left out can save you minutes per part. It may also help to create a simple fixture that will help orient the part in such a way that more detail is visible in a single set of scans. This can save some time by reducing the total number of scans in a set, and it will save a lot of time if you can reduce the total number of set-ups required for a part.

3. Depth of Field Compression

You can also reduce total scan time by optimizing the Depth of Field settings. Again, by spending a few extra minutes during the initial scan set-up you can shave off minutes of scan time per part.

To optimize the depth of field settings, set the software to ignore regions in front of the part and behind the part. Compressing the depth of field in this way increases the frame rate of the scanhead so that you can capture the same amount of data in less time. A simple fixture can come in handy here as well. If the fixture always holds the part in the same position then you can tighten up the depth of field without worrying about unwanted data loss.

4. Speed of Motors

To reduce total scan time even further you can increase the speed of the motors. There is a motor for each axis of motion in a Shapegrabber system; so, for a standard two-axis system like an Ai310, one motor controls the linear scanning axis and a second motor controls the rotary table. The linear scanning axis speed will be determined by the parameters mentioned above during a scan. However, the scanhead will be returned to a start position before beginning the next scan.

You can use the Properties settings to increase the “return to start” speed, or “non-scanning motion” as it is called in the software. By optimizing the speed of both motors you will reduce the time between scans in a set and further optimize total scan time.

For more details on any of the options discussed above, please contact the Shapegrabber support team at support@shapegrabber.com.