From new to end of life, welding tips used to spot weld the housing to the band create varied results. From time to time, a weld would fail to fully engage and would produce a light or no weld.
5000 images were collected and annotated, then applied to a neural network-based descision engine (predecessor to modern deep learning algrothims). System performed well after new tips were broken in after 2000 cycles. (Average life cylce of tips 35k - 40k)