Stem prints

Almost a year ago, I posted a rendering of my printed bike stem on my blog. Now, finally, they're here physically:

These parts were printed by my friends at Playground Global on their 3D Systems DMP320 in titanium 6/4. Like the titanium parts I've had printed (and written about extensively) in the past, these are done via laser metal powder bed fusion. These parts were, of course, designed in nTopology Element Pro; you can see more of my design process here. 

As loyal followers will know, I've put a lot of time into using Abaqus to predict these parts' mechanical properties; more on that in the near future. For the time being, the goal with this print was to test the manufacturing process - and use any lessons here to guide future design iterations. As you'd imagine, there's a *lot* that goes into printing a part that has ~45,000 beams; establishing manufacturing parameters was a good way to filter out nonviable design strategies.

It'll take a bit more work to characterize the as-built design fully, but at first inspection it seems to have been a total success. I was careful to keep most of the beams' orientations at a high angles, thicknesses above .45 mm, and lengths below 3 mm; the result is a structure that's almost completely self supporting.

At this point, the part has been roughly cleaned up and bead blasted to remove any surface discoloration. The next step is to tap the holes, clean up the clamp surfaces, and mock the entire assembly up.

More soon :)

See also: DMLS lattice sample prints, where I describe the part's design a bit more.