In the September '11 issue we introduced you to the Harbinger Mustang being produced by Agent-47 with a little technological help from their parent company Forecast3D. While at a passing glance it appeared to be another well-built muscle car with lots of hand fabrication (and it is), but much of the detail work was accomplished through high-tech rapid prototyping processes.
We explored and explained some of those interesting technologies later in the same issue in the feature titled The Future Is Now, and promised you a couple of dazzling videos to show the Stereolithography Apparatus (SLA) used to create the Tran-Am style airbox for Harbinger as well as the Direct Metal Laser Sintering (DMLS) used to create the Harbinger's chassis badge. Check 'em out below along with the descriptions from the feature as a reminder and a few extra photos of the Agent-47 airbox fresh out of the SLA machine.
Stereolithography Apparatus (SLA)
Stereolithography uses a vat of liquid UV-curable photopolymer resin (DSM 18420 Protogen resin in this case) and a UV laser to build physical objects one cross-sectional layer at a time, typically 0.05 mm to 0.15 mm. The laser causes each layer to cure, solidify, and adhere it to previous layer. When needed, a blade sweeps across with fresh resin to create another layer. Eventually a complete part emerges from the goo ready for testing.
Wonder what's spilling out of the finished air box prototype in the photos? Stereolithography requires support structures to maintain the form and position of the layers of resin as the laser is curing it into solid form. The tiny triangular mesh is generated automatically during the design phase and broken out of the part after it's completed.
Check out the video of the Harbinger's air box being created in Forecast3D's SLA 7000 machine in the embedded video below.
Direct Metal Laser Sintering (DMLS)
What looks like a finely cast badge actually started as powdered metal that was literally built up 20 microns at a time. After another fine layer of powder is laid down by a sweeping blade, DirectAlloy 718 for the badge, a 100-watt laser sinters the metal along the X and Y-axes into a solid layer. Much like SLA, a supporting structure is often built along the part that later gets removed. It's all about time here as well; DMLS can create complex metal parts using a wide array of alloys in days versus weeks. Because of that, it's slowly becoming the preferred method over CNC machining or investment casting for prototypes. Check out the video of a bracket being created in the embedded video below
It looks like perhaps a cut...
It looks like perhaps a cut scene from a movie about alien invasion, but this is actually a shot of the laser grid beginning one of the layers of the airbox in its bath of Protogen resin.
This is how the airbox looks...
This is how the airbox looks fresh out of the machine.
Check out the triangulated...
Check out the triangulated support structures that the SLA program automatically builds in to help maintain the shape of the box as the layers progress.
It looks like it would be...
It looks like it would be an issue to remove, but the structures are designed to detach easily without damaging the part.