Stoneridge in Tallinn, Estonia, recently installed the Nikon ALTERA CMM with LC15Dx laser scanner in its test laboratory to take inspection of automotive components to the next level. The laser scanner provides many advantages including complete visualisation of parts, non-contact measurement for delicate components and repeatable measurements.
Stoneridge is a global designer and manufacturer of highly engineered electrical components and systems for commercial vehicles, automotive, off-highway and agricultural vehicle markets. These parts are the core of mechanical and electrical systems and improve overall vehicle performance in areas such as emissions control, fuel efficiency, safety and security.
Founded in 1965, Stoneridge has a vast amount of experience in this field and will have a vital role to play in the future of automotive manufacture. With the developing trend of autonomous vehicles, and the constantly increasing emphasis on the environmental aspect of vehicles, the activities at Stoneridge now and in the future are of growing importance. Stoneridge manufactures application-specific switches and actuators, sensors, security alarms, vehicle tracking devices and monitoring services which are subject to extensive testing and quality control. These items are critical to the safety of road-users and vehicle security. Especially with autonomous driving on the horizon, component failure is not an option.
Creating part programs is very easy. The program will last for as long as the part is in production. The program is always there. Ready to use.”
Timo Jakimainen, Senior Engineer at Stoneridge.
Relying on suppliers for measurement and inspection after testing
With limited access to quality inspection tools, Stoneridge relied on suppliers’ measurement capabilities to provide feedback and results.
Anti Laas, Mechanic Design Engineer at Stoneridge says, “Since every measurement is money, we ask suppliers to do it, but they take a lot of time. They have their own projects, like measuring for serial production… so, it’s a long queue. You have to wait a long time, and we no longer have that time”.
The benefits of owning a multi-sensor CMM, or any comprehensive measurement systems were previously unknown for Stoneridge. For the engineers, the cost of a top of the range system seemed too much for what use they would get from it. At that time, sub-contracting the measurement tasks back to suppliers was the best value for Stoneridge. However, as operations grew and it was no longer productive to be sending all measurement work out of the factory, so the decision was taken to research the metrology market for a suitable solution.
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Learning about the laser scanning capabilities
Timo Jakimainen Senior Engineer at Stoneridge led the search for the new equipment, alongside his colleague Anti Laas. Although the initial search was to find a modern, accurate and productive CMM, it was Anti’s knowledge of laser scanning that opened up a whole new range of possibilities.
Anti explains that with a CMM and touch probing, data isn’t always useful. You don’t have the whole picture, you are basing what you know on a few points, a few dimensions. In some cases, information in this format can be manipulated to provide the results required. Therefore, due to the lack of full 3D data, it fails to reveal problem areas of a component, often hiding or obscuring the bad areas of a part.
According to Anti Laas, “If you’re only taking a few dimensions, you don’t know what is going on in another area of the part. With a laser scanner, it gives you a more holistic view… the full picture”.
The image below illustrates the problem which the team at Stoneridge found with using a CMM and how it was solved with the introduction of a laser scanner.
This part failed the tests multiple times, and the measurement results came back several times to show there were no problems, and it shouldn’t be failing. Still it failed. For the purpose of this component, the contacts were not required to be measured. The points used for measuring were around the base, but there were no problems found while the measurements added up. It wasn’t until the introduction of the laser scanner, that they noticed the issue. With laser scanning, you immediately see the whole picture. You immediately have visual representation of the part – as a whole – and you can see clearly where the problem is.
Timo summarises by saying, “with a laser scanner, you have much more transparency”.
If you’re only taking a few dimensions, you don’t know what is going on in another area of the part. With a laser scanner, it gives you a more holistic view… the full picture.”
Anti Laas, Mechanic Design Engineer at Stoneridge.
What results have been seen so far?
Some immediate benefits that have been seen at Stoneridge include the non-contact measurement. Rubber key pads for controllers, and electronic key fobs were very difficult to measure before the introduction of the laser scanner. Timo explains that they did what they could, but had to explain to clients that they couldn’t guarantee the measurements were absolutely accurate. By applying pressure, the touch probe would deform the rubber part, making the measurement void. However with the LC15Dx, it measures not only with a contact free laser and camera system, but from a short stand-off which enables the scanner to access hard-to-reach areas and visualise them with high accuracy, comparable and closely correlating to touch probing accuracy.
The introduction of the Nikon Metrology system has introduced other opportunities aside from the normal line of work. Something which the engineers in the test laboratory are looking into is measurement before and after testing. Some of Stoneridge’s clients already demand this. After going through its standard tests for IP class rating, or other environment simulators such as vibration and extreme temperatures the components will be subject to testing to see how the part has changed.
The capability of the system is encapsulated by the amount of requests from outside of the company. Stoneridge has also been working with the local university – which also owns a Nikon system for referring people for one-off or sub-contract inspection. More and more requests are beginning to come in from Estonian companies to use the Nikon system.
However, for both Timo and Anti, they agree that one of the most useful functions for what they need is the full visual colour comparison. With all of the data available, it can be represented in easy-to-interpret reports, saved and shared at the click of a button. If ever there are problems, or something that went under the radar, they can bring up the report, check it and share it.
To find out more about Nikon Metrology, visit the website here.