13. September 2010 - 14:14
#1
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Quality assurance for foundry
We want to monitor the quality of big components. Is laser scanning applicable for that purpose?
Former
What shall be monitored how accurately on which component? Some specific information would be helpful...
ak.
Hello ak.
You need 2 to 4mm measuring accuracy for big casting components. In the case of smaller components, the measuring accuracy should be less than 1mm. Are there scanners which meet this requirement? Are there special requirements concerning the components’ surfaces? I can imagine that this is an issue.
Former
Hey,
I want to put in my two cents.
In general, laser scanning is suitable for e.g. generating in size a variance analysis of castings.
Nevertheless, the choice of the scanner is the crunch:
Look around in metrology, especially portable metrology. There are many 3D scanning systems which work with a very high measuring accuracy. 0.1mm are normal there. At first, this sounds like being overkill for your purpose. But if you want to verify a variance of 2mm of your component, you should be able to measure 5 to 10 times more precisely. Otherwise, it will not become explicit in your analysis if potential variances arise from the component or the measuring system.
In this field, providers are for example GOM, Steinbichler, Cognitens (light-pattern projector) Faro, Romer, Nikon Metrology (measuring arm with scanner), Leica T-Scan (laser tracker with scanner).
I have had very good experiences with Leica T-Scan on castings. Combined with a Leica T-Probe, you can center-punch the components extremely effectively. The time saving is frequently 8 to 9 hours and more.
The choice of the measuring system depends on the size of you components, of course. It would be helpful if you provide the information with regard to this point.
I think terrestrial laser scanner (Leica HDS, Faro Photon, Trimble, Riegl etc.) are not very suitable for this application because, in this case, you work on the edge of specification (measuring accuracy) and because, in the case of more complex components, many opacities are normally generated in the point clouds. You can try to eliminate these opacities by a number of positions of the scanner. Even the surface's shape and color (slanting laser impact angle) affect the measurement result negatively.
For your application, you need a sensor which can resolve far below 1mm.
I hope I could help you in search of an appropriate measurement method!
Regards,
Olaf