b'Force Multiplier pulls the bar through the spindle.utilized small robots to load VMCs. Pullers are very straightforward de- A tray full of parts would move down vices that cost only a few hundreda conveyor where a robot would making is value-added time. Wedollars whereas a good bar feederload and unload the pieces. It took all agree that setups, tool changescosts many thousands of dollars.only a few seconds to put the raw and all similar activities, necessaryIn a pinch, a good machinist canmaterial onto the tray, and one tray or not, are non-value-added time.make a puller with materials fromwould keep the robot busy for an Anytime we can give a tool to a ma- the shop in a couple of hours. hour. Each conveyor held multiple chinist that allows him or her to ef- One of the more creative solu- trays, which meant that the robot fectively conduct multiple simulta- tions that I have seen was a verti- would run uninterrupted for hours. neous operations, we have createdcal machining center set up to bar- One person tended nine VMCs and a force multiplier. feedwithout a bar feeder. Theproduced over 2,000 parts per shift. One of the most effective andshop used a small CNC mill to cutPrior to adding the robots, one per-oftenoverlookedstrategiestoparts out of square stock. The stockson was at each machine.improve productivity is reducingwas clamped in a 5C collet held inCollaborative robots, also known non-value-added time invested ina fourth-axis rotary device. Onceas cobots, are robots that can work raw materials. Preparing them forapartwascomplete,theVMCin the same environment as hu-Anytime we can give a tool to a machinist that allows himor her to effectively conduct multiple simultaneousoperations, we have created a force multiplier.machining operations is usuallywould use a small saw blade to cutmans. For safety, traditional indus-a lower-skilled job with generousthrough the part, which would falltrial robots had to be isolated with tolerances, making them perfecton the table. The VMC then wouldbarricades in dedicated cells. Co-for applying creative tools as forcedrill a hole into the square bar. Withbots, however, can detect abnormal multipliers. the drill inside the hole, the colletforces and immediately shut down Automating cutting operations bywould unclamp and the VMC wouldwhen colliding with something like using an automatic saw is the easiest,pull the bar through the collet toa person, which makes cobots safe fastest way to add a force multiplierstart a new part. This way, the ma- enough to work alongside people.at a shop. Sawing is the most com- chine would run unattended, allow- Cobots are becoming increas-mon method for turning raw mate- ing the machinist to perform otheringly popular because they are safe rials into workpieces. Adding an au- tasks. It cost almost nothing to au- and extremely flexible. Many com-tomatic bandsaw or cold saw to atomate this process. panies have them mounted on mo-machine tool lineup immediately re- Robotic loading and unloadingbile platforms that can be moved turns dividends by freeing peopleare becoming increasingly commonaround a shop and used for many toperform more complex jobs. at shops. When done well, roboticdifferent operations. Cobots will More effective than automaticloading is extremely efficient. Withbecomeubiquitousatmodern sawing is to separate a workpiecerecent advances in robotics, thereshops, and I expect to see major from raw material at the machineis a lot of flexibility that didnt existmachine tool makers begin to offer tool. A good example is adding awith robotic technology in the past. cobots as options already attached bar feeder to a lathe, which is a veryAtapreviousemployer,weto machine tools.simple but effective way to elimi- These are just several examples nate sawing operations. Bar feedersabout the authorof the force multipliers available to are common, and most new CNCmachine shops. Many other things lathes come wired for bar feeders. Christopher Tateon the market reduce handling If you cant justify the expenseis manufacturingtime and allow people to create of a bar feeder, use a bar puller. Aengineering man- more value with fewer resources. bar feeder is an external tool thatager at UnifiedFuture success will require shops pushes the bar through the machineBrands Inc. into continue seeking ways to elimi-Vicksburg, Mis-spindle. A bar puller is mounted onsissippi. Contactnate waste and get more value from the turret and, as the name implies,him at [email protected]. scarce means.CTE30DECEMBER 2022 PartsHandling.indd 30 11/15/22 2:30 PM'