Index's Michael Huggett

1. Cam-driven machines are highly susceptible to producing scrap. Lacking the monitoring systems common on today’s CNC machines, a small issue with chip evacuation or tool wear can cause hundreds of parts to fall short of required tolerances before anyone realizes there’s an issue.

2. Cam-driven machines tend to have much lower utilization rates than shops are accustomed to having with modern machines. Long warm-up times and the need for frequent manual intervention limit the percentage of time machines can be making parts. Manufacturers are also facing customer demands for smaller lot sizes. With the long, labor-intensive changeover process required by cam-driven machines, utilization rates can drop steeply if a shop is trying to stay competitive amidst current trends.

3. A shop should perform an analysis to determine effective cycle time to get better insight into its cam-driven machines’ performance. This could be as simple as counting the good parts produced in a week and dividing it by the total amount of time the shop was in operation. In many cases, shops will discover their effective cycle time to be two to three times higher than expected. Often, a CNC multi-spindle will produce more good parts during the same amount of time.

4. When a cam-driven machine is replaced with a CNC multi-spindle, labor cost per part will drop. It simply takes far less work to produce good parts on a modern CNC multi-spindle than it does with a cam-driven machine. Because of their capability to fully produce parts in a single setup, CNC multi-spindles also frequently eliminate the secondary processes required on a cam-driven machine. This further reduces labor cost and frees up other equipment to be used for other jobs.

Many shops finally retire their cam-driven machines due to the space they take up. Depending on how the older machines are being operated, upgrading to a CNC multi-spindle can dramatically increase the part output per square foot of floor space. If a shop has a large department of cam-driven machines operating at or near full capacity, upgrading to more advanced equipment is more cost effective than expanding or replacing a facility.

5. Shops still operating cam-driven machines should note how close their relevant operators are to retirement. Keeping these older machines in operating condition can be as much art as science. Young people entering the workforce today tend to focus on the latest technology as opposed to learning how to operate machines requiring specialized skills that don’t transfer well to other positions. With the competitiveness of the labor market and an aging manufacturing workforce, it may be costly or impossible to replace cam-driven machine operators as they retire.

More information: www.index-group.com