Pump impeller

The tool-less production of moulds using 3D print Technology

Sand casting molds from 3D printers give foundries a great many advantages – from shorter throughput times to less post-processing work and even better surface quality of the unfinished cast parts. 
The Dutch pump manufacturer Nijhuis casts pump housings and impellers that weigh up to 800 kilogrammes. The Dutch engineers were impressed by voxeljet's service centre and see enormous potential in on-demand production of sand molds for metal casting. "Particulary a company like ours, which manufactures many prototypes and small batches, will benefit a great deal from the innovative 3D printing technology where time and quality are concerned," says Nijhuis development engineer Luke Vrielink.

In conventional prototype manufacturing, it takes months to go from the drawing to the finished cast part. It's an entirely different story with 3D printing, where the throughput time is significantly shorter. Once the CAD design has been completed, the information is e-mailed to voxeljet's order processing department. A 3D printer generates the molds automatically and without tools in a layering process, based on these 3D CAD data.

The VX4000 high-performance printer can print sand molds in what may be record-breaking dimensions of up to 4 x 2 x 1 metres. The laborious and costly route to the otherwise necessary mold set-up is dispensed with. Even complex geometries can be generated with a high degree of precision and detail accuracy. Depending on the size of the piece, the printing process will take one to two days.   

Thanks to the 3D printing capabilities, the pump manufacturer can ship products faster even while reducing its stock. "The fact that we can now have the large sand molds printed at voxeljet means that we are able to ship quickly even if the model is not in stock," says Luke Vrielink. The development engineer also finds the higher quality to be a significant advantage. With 3D printing, the sand molds correspond 1:1 to the computer model, while small deviations can always arise when producing them manually. The cost of remachining the parts is minimised by the smaller allowance. "This technology enables European foundries to become more competitive," states Luke Vrielink with confidence.

 Technical data

Total size                   852 x 852 x 428 mm
Weight 269 kg
Individual pieces4
Material Sand
Layer thickness 0.3 mm
Lead time 10 days
Build time 13 hours