Case Study

Smart camera based Telecentric measuring system quickly and accurately sorts cartridge cases

This British company was established in 1828, and has a long and proud tradition in the high standard of manufacture of rimfire ammunition. Specializing in .22 calibre cartridges, the customer is widely regarded as the world leader with its flagship product , sold in more than 130 countries.

The customer needed to accurately sort cartridge cases for the top range product. The cases needed to be inspected for length, rim diameter and thickness and any damage. Tolerances of +/- 0.001” are used with a system resolution of 0.0002”. 

Cases are fed from a bowl feeder, via a linear feeder to a star wheel which holds the case vertically by the rim. A Vision & Control Pictor smart camera with telecentric lens takes a silhouette image using a telecentric backlight. Parts are sorted based on length and rim good, rim good and fail such that length failures can be used for lower grade production and limit the overall scrap rate.

The vision system makes extensive use of sub-pixel inspection using edge, best fit line, line-edge and edge-edge measurement techniques. The use of a telecentric lens and light to create the image ensures highly accurate measurements can be, this could not be achieved with standard lenses and backlights, particularly due to the reflective nature of the brass material the cases are made from.
FS Systems worked with Birmingham based MKL Automation to produce a star wheel inspection system with bowl feed input