Finally, a Blog on Additive in Precision Machining

August 8, 2017

Excitement!

I’ll admit it, I’ve been a bit of a curmudgeon regarding Additive Technology in manufacturing. While everyone in the trade press seems to be gushing breathlessly about additive technology like a bunch of tweens waiting for their first One Direction concert, I’ve stayed away.

I’ve stayed away, because until now, most things that I saw were mere novelty applications. Distractions, or lets face it, quite impractical. Who needs a 3-d printed plastic wrench?

A very nice project but not really a useable tool in most situations.

 

What have been some of my objections?

  • No  practical mechanical properties. Or else requiring a very expensive thermal treatment to develop mechanical properties that are still below those of traditionally wrought products.
  • Low density. Or higher density achieved by absorbing a molten metal at high temperatures like a wick.
  • Cycle time. building a part a thousandth of an inch or so per pass takes a long time. Even watching the laser pulses  as it builds up features, layer by layer gets old after a few passes.
  • Tolerances. Newer technologies are getting more precise, but  the tolerances  claimed haven’t exactly been  “hold my beer watch this!” impressive.

So what has changed my thinking about Additive in our Subtractive precision machining world?

NanoSteel BLDR Metal for Powderjet Fusion

  • Mechanical properties objection- With case-hardening steel powder that provides high hardness and ductility (case hardness >70HRC, 10%+ core elongation)  that objection is gone.
  • Low density objection- If it is dense enough to perform as roll threading dies, that objection is also moot.
  • Cycle time. Well, the video doesn’t say how long it took to fabricate these thread roll dies, but my guess is it probably took less time than the time to find, purchase, ship and deliver the tool steel needed to fabricate new ones by traditional machining methods.
  • Tolerances. Now, they don’t share the tolerances achieved in this video, but it seems pretty clear that their claim of making tooling capable of fabricating the bolt shown is credible.

So there you have it.  A credible role for Additive in our Subtractive precision machining shops.

I’m impressed. So impressed, I wrote this post.

Now where do I find tickets for One Direction???

NanoSteel.

Excitement Photo     Courtesy Mama Bird Diaries.

Instructables Plastic Wrench 3-d Printing