VMC have long been the workhorse in smaller shops, especially because of their lower initial cost. However, for shops that work on various sizes and complexities of parts, the overall cost of an HMC is actually less than a VMC. Here’s why:
Increased machine utilization. A number of studies, including one conducted by the University of Michigan, found that the average shop VMC utilization, as measured by spindle runtime, is 25% versus 85% for HMC. That’s a lot of idle spindle hours you could eliminate by switching to an HMC.
Greatly reduced part handling. Let’s say you’re machining a six-sided workpiece on a VMC. Typically, the operator will move that part seven or more times, in and out of various machines and fixtures. Machining the same part in an HMC requires no movement of the part to another machine and only a few touches by the machine operator. Clearly this represents a significant reduction in labor costs, less spindle downtime and fewer opportunities for human error that lead to scrap and rework.
Fewer fixtures. Using one HMC in place of multiple VMCs means less money spent on acquiring and maintaining special fixtures.
Setup time savings. Using multiple VMCs requires a great deal of setup time while, again, adding more operator touches and increasing the potential for human error.
Requires less floor space. One HMC can easily replace four VMC. Saving all of that shop floor real estate could translate to increased capacity and more efficient workflow.
Better use of operator time. If you’re machining a part on four VMC, you either need four machine operators, or one operator walking the part through all four processes while the other machines stand idle. On the other hand, one operator can easily manage a single HMC.
Less maintenance. All machine tools need routine maintenance, and keeping one HMC in peak operating condition is far easier – and less expensive – than maintaining multiple VMC.
There’s certainly a place for both vertical and horizontal machining centers in many shops. The Gosiger machine tool specialists can help you determine the most efficient CNC machines for your specific needs. Learn more by contacting your Gosiger facility.