3D printing of prototypes to reduce time-to-market

Time is money. A lot of time is a lot of money. This also holds true when it comes to the production of prototypes. That is the background for Danfoss’s participation in the development project 'Reducing turnaround time by 3D macro printing of prototypes,' which explores the possibilities for 3D printing prototypes in aluminium.

"It can take us a total of two weeks to produce a prototype by processing a block of aluminium in the traditional way. That, in itself, is expensive due to labour costs and machine depreciation, and it may require three or four prototypes before the final result is achieved. But most important of all is time-to-market. Several hundred thousand kroner can be lost per week," says Steffen Schmidt, Segment Head & Platform Architect in Additive Manufacturing, Danfoss Drives A/S.

For Danfoss, the project has focused on an aluminium enclosure for a frequency converter used in the beer and bottling industry, with the goal of 3D printing a prototype that is comparable to a traditionally manufactured prototype in terms of thermal, electrical, mechanical, and hygienic properties.

Laser and powder present challenges

FORCE Technology is responsible for testing various additive manufacturing (AM) technologies, the first of which was laser cladding/3D printing with AISi12 aluminium powder.

"We built, for example, a wall on an aluminium plate, which is comparable to the side of an aluminium case. But the aluminium powder is difficult to work with. It boils, causing microporosity in the form of air bubbles. This could be due to the type of powder, but it might also be the laser generating too much heat," says M.Sc.Eng., Ph.D. Steen Erik Nielsen, who is responsible for the project at FORCE Technology.

To avoid overheating, it is necessary to insert pauses between the building of the layers, which increases production time. On the other hand, it appears that the time can be won back by optimising the software programming, so the 3D-printed component requires only minimal post-processing.

3D printing with CMT welding

In the short run, another well-known technology seems to be the most useful for Danfoss. FORCE Technology has also 3D printed an aluminium enclosure using MX3D software programming, CMT welding, and aluminium wire.

"The method produces a somewhat rougher part, but it is much faster because there are not the same challenges with heat and air bubbles. We can 3D print a prototype in half an hour," says Steen Erik Nielsen.

There is also the finishing process, but regardless, it is a completely different production speed than Danfoss is used to.

"We must at least be able to halve the time consumption and costs before it is interesting for us to invest in new ways of producing prototypes. So if the 3D-printed aluminium box has approximately the same properties as our traditional prototypes, the solution is absolutely relevant for us," says Steffen Schmidt, and praises FORCE Technology for thinking outside the box.

"FORCE Technology changed course and came up with the arc welding solution when it wasn’t immediately working with laser and aluminium powder. I am a big fan of using established and well-tested technologies in new ways, and this solution could have perspectives across all of Danfoss. We are 28,000 employees worldwide, half of whom are engineers, and we produce tens of thousands of prototypes every year," says Steffen Schmidt.