Do not let limited thinking limit your productivity. This is a guideline every machinist designing the set-ups should adapt because it is often the machinists imagination that will be setting the limits in this designing process. Wedge clamps in general are a very good example of flexible clamping elements that enable creative fixturing designs because they are so versatile.There are few basic things that one has to take into account when choosing a fixturing devicesuch as three directional machiningmultiple parts fixturingease of useetc. Herewe will look at some important features that a flexible clamping devices should have in order to be able to create versatile fixturing solutions.One of the main features of wedge clampssuch as the OK-VISE low-profile clampsis their small size. This will give them a major advantage in comparison to standard station vices taking up a huge workspace in a machining table or column. The low-profile clamps are designed to fit between the pieces to be machined and take up very little space on the fastening base itself. Of major importance in designing the fixture is the extent to which the capacity of each fastening base can be usedor the number of workpieces that can be machined at the same time. In other wordsdesigning the free workspace so that you can fill your t-slot table or your columns with as many workpieces as possible is as important to reducing production time and improving machine productivity as is the speed of the machine. Clamping more workpieces reduces downtime and increases the amount of time the machine is actively in production. Increasing productivity without adding operating hours is extremely important. When you will succeed in longer machine cycles you will also free the machinist to execute other tasks while the machine is running. Wedge activated low-profile clamps are ideal when multiple parts clamping is executed. They function on the principle that when the wedge is tightened down the jaws on both sides expand simultaneously thrusting the workpieces to be machined against the locating guides. The precision of the fixture comes directly from the precision of locating guides and multiple parts can be clamped on both sides. The OK-VISE system ties in with a new machine tool purchase as it can be used on an individual machine just as successfully as in large flexible manufacturing systems. No additional investments other than fixed stoppers or locating guides are required. A simple fastening operation involving one bolt (M5-M16) ensures quick set up times and ease of use. The design is universal and they fit to any table or column available with no need to purchase separate expensive parts like base railsjawswedgesetc. adding up cumulatively to the overall cost. This is extremely important point especially during the recession when new investments are put into ice and productivity becomes the issue. With a very small investment in low-profile clamps one can make great savings through improving the old fixtures to a more effective level and getting this way the best out of the existing machinery. The special wedge structure of OK-VISE low-profile clamps ensures that the clamps are locked firmly in every direction in both the horizontal and the vertical planes creating absolute stability when tightened down. Howeverwith the conventional vices it is common that the final tightening phase tends to elevate the workpiece. Single-wedge low-profile clamps keep the workpiece steadily in place not allowing the upward or downward movement of the workpiece and the double-wedge model creates an extra pull-down action towards the fastening base. The structure cuts out all the sliding of workpieces ultimately resulting to no sideways deviation. This leads to improved accuracy and reduced quality control measures. Wedge clamps are normally small in sizebut it does not mean that they are small in clamping force. Indeed these clamps generate the clamping force that clearly exceeds the force imposed by the machining forces. It is possible to achieve clamping forces close to 200kN on both sides simultaneously. This makes the clamp very reliable and many customers are using them on machines unmanned during the night or at weekends. Moving around from one application or machine to another is virtually effortless. One bolt fastening makes easy using a reality both in manual as well as in CNC machine tools. At the end of the day the less you will have to turn over the workpiece during the machiningmore precise will be the outcome. This is why the possibility of three directional machining of workpieces has become important. Small low-profile clamps fit in between the workpieces and leave all three planes free to be machinednot blocking the spindle during the operation. Parts fixturing probably represents the best value in today’s metalworking technology. If you calculate the cost of a CNC machine toolthe cutting toolstool holders and tool changer with both the programming and design software and compare these investments to the cost of your fixturing equipment. Fixturing normally costs only a fraction of the amount the others cost. The potential for time savings and process improvements offered by a good fixturing solution are substantial. Butin addition to a good fixturing systemit is equally important to have operators capable of implementing innovative and creative fixturing solutions to get the best out of the existing machines.Enter 47 or at www.engineerlive.com/ede Sami Salila is with OK-VISE OyMuurameFinland. www.ok-vise.com
