Page 23 - 3D Metal Printing Fall 2018
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 between the velocity at which the water or oil exits the nozzle and the grinding speed. If you know the grinding speed, then you can achieve adaptive control of the pressure with the aid of the Grindaix nozzle flow-rate diagram. So we can tell our customers exactly what pressure they should use upstream from the nozzle to achieve a specific coolant exit velocity in the grinding process. We never had been able to achieve such tremendous precision in nozzle applications for ID cylindrical grinding.”
While pleased with the new nozzle, Friedrich does not conceal drawbacks associated with 3D printing. “Sintered parts have a rougher surface than those made from conventional metals. On the outside, at least in our case, we can cor- rect this issue through polishing. To elim- inate the roughness on the inside sur- faces, which would once again lead to flow losses, we pump an abrasive fluid through the coolant nozzle at high pres- sure.” To achieve a tight seal, a separate process corrects the connecting thread’s roughness.
On the plus side, the 3D-printed nozzle requires two production steps versus four for the original nozzle. Friedrich contends that the high flexibility of the process sig- nificantly outweighs the disadvantages. “This nozzle would be impossible to pro- duce without 3D printing,” he says.
Schmidt-Lehr agrees: “In many cases you don’t actually need smooth surfaces, they are just a side effect of the drilling or milling process,” he says. “But in cases where smooth surfaces are vital, rework is inevitable.”
Schmidt-Lehr finishes off by clearing up another myth: “Many companies seem to think that you can make any compo- nent using 3D printing and that it will be cheaper. Nevertheless, this method really is suitable only for a small number of parts. When you do get the right match, however, the benefits can be huge.”
50 Nozzles at Once
Though still a development project, some Grindaix nozzle customers are using
the nozzles, with Friedrich expressing optimism about their future sales poten- tial. “We’ve already progressed well beyond the prototype stage,” he says. “Together with Trumpf and Bionic Pro- duction, we have been developing con- cepts that will allow us to print 50 different nozzles at once. That obviously will obvi- ously have a positive impact on manu- facturing costs.”
Clearly impressed by the flexibility of 3D printing, Friedrich enthuses, “With all the know-how we’ve accumulated in this joint project, we would certainly consider producing 3D-printed parts ourselves in the future.” 3DMP
Information for this article was supplied by Trumpf, Inc., Farmington, CT; 860/255- 6600,
Optimization Yields Efficient Coolant Nozzles 3D

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