Spindle Uptime
JULY 2009 www.modernwoodworking.com 24 H ow much time a spindle is spending producing parts versus how much time an operator is spending pull-ing one sheet o and putting another sheet on a CNC machining center proved to be the impetus for implementing a new work center at Crystal Cabinet Works. e result has been a reduction of material handling by more than 65 percent. Since 1947 Crystal Cabinet Works has been manufactur-ing custom and semi-custom cabinetry for the residential and commercial markets. One of the largest privately owned custom cabinet manufacturers in the U.S., the company now manufactures in a 324,000-sq.- . facility with 385 employees, selling to all 50 states plus Canada and Mexico. Requests for the services of the Princeton, Minn.-based company come from a combination of architects, designers and independent dealers. At the heart of Crystal Cabinet Works' new work center are two new Komo CNC machining centers. CNC machinery is certainly not new to the company, but this time there is a big difference automatic loading and unloading material handling equipment has been included. Spindle uptime is the most important factor in improving CNC performance, says Nick Weis, director of engineering and technology. Originally, we were not going to purchase the material handling equip-ment. But when we did a dry run and saw how much more time the spindle spent actually producing parts when material handling li s were operating than when an operator was load-ing and unloading sheets, there was too big of a di erence. e company's time from sheet to machine is 12 seconds. Prior to that, it was in the minutes since the spindle would be waiting for the operator to hit the start button again while he was busy pulling o the old sheet and putting on the new one. We make a kitchen at a time so CNC performance is vital, says Weis. is new work center manufactures the box work components and has improved productivity by 38 percent and yield by 7 percent. In fact, the whole process is faster. We have gone from three weeks throughput to three days. From hodgepodge to continuous improvement Weis has been with Crystal Cabinet Works for 24 years and dur-ing that time has seen many changes as far as e ciency goes. In the past, our processes were somewhat hodgepodge, thrown together with panel processing and not nested-based, he says. We did some studies and determined that we were stock-ing a lot of our parts, inventorying those same parts year a er year and subsequently not really selling all that we were mak-ing. Due to a thorough analysis, we determined that we would be able to save a signi cant amount of money by going from panel processing to nested-based manufacturing on a kitchen-to-kitchen basis. Now we don't stock anything. Since the early `90s we have been into J.I.T. manufacturing, which is now referred to as the lean manufacturing philosophy. Crystal Cabinet Works' equipment purchasing decisions are somewhat based on future payback, but the real strategy is one of continuous improvement. If we see a process that has become a bottleneck or has the potential for a bottleneck, we look through lean manufacturing principles to nd the ways to eliminate the waste that could be causing it, says Weis. In addition, if a machine is really outdated or just can't handle the volume, we will look at replacing it. We do a thorough analysis of the ow of the material, value stream and gure out where we should put each piece of equipment based not only on space available but also by how much time we can reduce in what we call `walk time' between operations. Crystal Cabinet Works has six di erent lines of cabinets, By Brooke Baldwin Wisdom Spindle uptime Material handling is key to cabinet company's optimal CNC performance Princeton, Minn.-based Crystal Cabinet Works has reduced its material handling by more than 65 percent.