The precise prism toolholder type PRISMO clamps every shank diameter between 5 and 20 millimeters
With its eroded prism guidances, PRISMO the toolholder for tool grinding from SCHUNK clamps different shank diameters with a repeat accuracy of less than 0.005 mm.
Without any doubt, the PRISMO tool grinding toolholder from SCHUNK is one of the highlights of this year's GrindTec show. With its variable clamping diameter, a threefold prism guidance, and intermeshed chuck jaws, the all-purpose mounting achieves high repeat accuracies of less than 0.005 mm and avoids tube unbalance almost completely. These are ideal pre-conditions for automated manufacturing of small batch sizes.
A threefold prism clamping provides the basis that the toolholder can clamp shaft diameters from 5 to 20 mm precisely. Each of the five chuck jaws is guided by an eroded double prism. A third prism is eroded on the clamping face, which directly contacts the tool shank. Thus the toolholder always adjusts itself to the individual tool diameters. This is an important difference towards conventional solutions, where the clamping face is just circular ground. Even deep hole drillers and tools with a twist, can be machined precisely with the PRISMO.
During the clamping operation, the five hard material coated chuck jaws intermesh. The build-up, the basic sleeve and the robust design provide a high stiffness to the toolholder. Moreover, the stable guidances reduce a "swing-out" of the grinding wheels. At an overhang length of 2,5 x D and a tool diameter of 20 mm, the PRISMO provides a repeat accuracy of less than 0,005 mm. In order to avoid pollution and to offer a permanently high precision, the PRISMO is rinsed during the grinding operation with clean oil.
No matter which tool diameter is to be machined, the X-axis of the grinding toolholder remains unchanged. All the chuck jaws persist on the identical axial position. Time-consuming additional programming and the danger of a crash due to incorrect axis offsets, are now in the past.