MoldMaking Technology

AUG 2015

Advertising in MoldMaking Technology offers

Issue link: https://mmt.epubxp.com/i/544238

Contents of this Issue

Navigation

Page 27 of 67

Machining 26 MoldMaking Technology August 2015 example, 3 to 5 microns). Typically, a machining center with a traveling column design incorporating a fourth/fifth-axis swivel table is better than a typical bridge or trunnion design. Traveling-column machines offer an optimal solution for that well-balanced part size. Mechanical design. Once a balance is achieved in a machine's design, it's important to balance the mechanical design as well. The guiding system, toolchanger and storage cabinet, along with the laser measuring system for the cutting tools, should be closely accessible around the cutting environment. This pro- vides further control of precision and productivity. For example, optimal dimensioning of the guiding system yields greater precision due to the smaller load on the guides and reduced moving mass. Both are inherently achieved by a well-designed guiding system. Additionally, keeping the laser close to the working environment results in greater accuracy, since smaller travels increase precision and productivity. The toolchanger and storage cabinet should also be located near the working environment, easing tool management. Exact-position tool-changing further increases precision in the tool-change cycle by maintaining the exact radial location of the toolholder from the toolchanger to the spindle. New develop- ments in tool-storage design make it possible to incorporate tool pal- letization, which was previously restricted to parts. Thermal control and compensation. Machines undergo constant thermal changes due to heat transfer among the spindle motor, drives, guiding system, cool- ant, machining process and environment. Controlling this heat and thermal expansion requires proper temperature manage- ment and an understanding of machine structure, including the construction material of each of the systems/machine compo- nents. A conservative material choice, one that responds slowly to thermal changes, is one with high thermal capacity and low thermal conductivity, such as steel, cast iron, granite and poly- mer concrete. However, because these materials have a slow response to changes in thermal conditions, they can yield short- term thermal errors. Solutions like these often conflict with machine dynamics and lengthen temperature-transient cycles A combination of integrated automation and a large ATC can boost productivity in a small machine footprint.

Articles in this issue

Links on this page

Archives of this issue

view archives of MoldMaking Technology - AUG 2015