The technology of laser sintering offers manufacturers of precision tools large degrees of design freedom. Within the space of the laser printer, tool geometries can be created unhindered by machine clamps, tools and production means. A broad and continually expanding range of materials is also available for the laser sintering process. MAPAL has therefore tried to produce tools by laser sintering that cannot or cannot optimally be produced by conventional means. One example are small diameters of the QTD insert drill originally brought to the market in 2013.
Optimum cooling channel design possible using laser sintering
The QTD has been available as standard from 13 mm diameter. Responsible for this is among other facts the cooling duct in the basic tool body. Normally in tool bodies with constant helical pitch for insert drills, the coolant is fed centrally to the front where it is then distributed to the inserts via a Y-fork. The smaller the tool body, the more this coolant supply system impairs the performance of the tool, because the central coolant supply weakens the core of the drill and makes it unstable. Furthermore, the coolant channels have to be made increasingly smaller. This results in a decreasing flow rate of the coolant to the insert at the front. Steel tool bodies with the spiral cooling ducts that are common in solid carbide tools are not yet common in small diameters.
The use of laser sintering for the production of the tool body opens up new degrees of geometric freedom. Tool bodies in the diameter range from 9 to 12 mm with spiral coolant channels are now being produced on the 3D printer. Compared with the central coolant supply with diversions, this design permits a 100% increased coolant flow rate, particularly thanks to the deviation from the circular coolant channel profile. Furthermore, hybrid models are possible in which the conventional and the additive sinter production are combined in order to further improve the cost-effectiveness of the production process.
Illustration:
Production of tool bodies for the QTD insert drill using the 3D laser sintering process.