In this discussion with Billy Smetana (SMB-Services Can Printing Solution), he shares his experiences and insights regarding the carriage system, a critical component in can manufacturing.

The carriage plays an essential role by moving the entire can handling section in and out against the blanket wheel, facilitating the necessary movement for printing. If a can is improperly loaded, the entire machine is tripped back, resulting in the removal of five to seven cans surrounding the damaged one to prevent printing issues.

The carriage operates on four cam followers, which are supported by small wear plates. The wear plates, made from hard steel, provide a durable surface for the cam followers to roll on, preventing grooves that could lead to operational issues. However, these plates can only be used a limited number of times before they risk cracking under the weight of the fourteen-ton carriage.


Billy recounts a situation where a customer had two decorators, one functioning properly and the other not. Upon inspection, he discovered a broken wear plate on the problematic machine, which caused the entire carriage to be misaligned.

Defects in the cam followers or wear plates can lead to visible issues in the printing process. Symptoms include faded prints and uneven overlaps, which can result from increased pressure applied to compensate for alignment problems. Over time, this can lead to additional mechanical stress and potential damage.


Billy emphasizes the importance of regularly checking the condition of the cam followers. If screws securing the cam followers are not tight, they can lead to excessive wear in the casting, causing instability in the carriage movement.

Operators should conduct regular inspections to ensure the carriage system is functioning correctly. Using a depth gauge to check the carriage height can identify discrepancies that may require maintenance. While some can makers perform this maintenance in-house, many prefer not to due to the complexity and confined spaces involved.


In summary, understanding the intricacies of the carriage system and conducting regular maintenance is vital for ensuring consistent quality in the can printing process.