Optical Measurement Innovation
How To Meet The Print Without Breaking The Bank. A case study in optical measurement innovation using automotive flanges manufactured by TFG USA.
Introduction – small businesses need accurate measurements too
You have a small manufacturing business. But, you still need accurate dimensions for your production part qualification process. You can’t afford a full-blown metrology department with a giant CMM (coordinate measuring machine).
There is an innovative solution using machine vision to measure your parts. A high-resolution off-the-shelf scanner can be combined with a free optical measurement analysis program to get you the accuracy you need. You can now enjoy this new part measurement capability.
It’s a new complement to our suite of measurement devices now available for you.
Pictured Right / Above: The high-resolution scanner we used for this case study.
Advantages of optical measurement software
Optical measurement is a fast, economical way to measure features on planar surfaces.
Here are some ways that you can benefit from optical measurement software:
- Measurement values can be displayed using custom number formats—as required by you or your customer.
- Theoretical features can easily be calculated and displayed (e.g., locations of theoretical sharp corners formed by two edges or the center of a hole.
- Critical fitment data can be easily calculated and displayed (e.g., the distance between centers of two holes—to fit over two studs on the mating part).
- Custom variables can be defined for plotting and analysis.
- Editable text columns for comments or manual data entry can be easily added.
- Data (raw or formatted) can be easily exported to a spreadsheet or other analytical software for additional analysis.
Pictured Left / Above: Illustration depicting critical fitment between threaded studs and the hole centers of the CNC-Machined Automotive Flanges (described in this case study)
Applications – accuracy without the complex setup
The inspection process demands accurate measurements. Every measurement system has its strengths and weaknesses.
The strength of this measurement methodology is that it provides capabilities that aren’t easily achievable with other available tools. The distance between hole centers is often a critical fitment criteria. Getting accurate manual measurements is tedious.
By establishing points on the arc of the circle, you can calculate the center point. The benefit of this methodology is that you can easily determine center-to-center distance conformance to the fitment criteria after you calculate the center points of two or more holes.
Pictured Right / Above: Calibration stick in blue. This is a measurement of a product. In red is the calculated distance between the center points of two holes—a tough measurement to get manually.
Observations – methodology leads to repeatability
This measurement methodology gives you high resolution — less than +/- 0.001” linear and less than 0.5° angular. The scanner resolution is critical for measurement accuracy.
The system is limited to the evaluation of planar / flat surfaces that will fit on the scanner bed (roughly 8.5″ x 11″ for our current setup). When used skillfully, it can give you an accurate visual record of the part analysis (see below).
Measurement systems that are not fully autonomous are susceptible to user variation (i.e., the user must accurately place the software’s visual markers on part characteristics).
Our operators are trained to produce accurate and repeatable measurement results for you.
Conclusions – accuracy with economy
It was possible to build a cost-effective optical measurement system with off-the-shelf parts and readily-available software.
This system fills the need for many clients who need accuracy with economy.
We were able to understand the strengths and weaknesses of this measurement methodology to use them to our customer’s optimal advantage.
Now it’s your turn
If the thought of accurate, economical measurements appeals to you, then contact us to learn how we deliver precision quality parts to customers just like you.