Metallic Glass Gears for NASA Robots

Had never seen a harmonic drive (mentioned in the article) in action, this video rendering showing how it functions is fascinating: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bzRh672peNk" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bzRh672peNk</a>

As an interesting aside, anyone who is interested in this stuff should check out the Omega Tau podcast(<a href="http:&#x2F;&#x2F;omegataupodcast.net" rel="nofollow">http:&#x2F;&#x2F;omegataupodcast.net</a>). In a recent episode(#247), he went in depth with Dr. Hoffman about his research and the uses of BMG materials.

As another interesting aside on these gears -- besides the very cool materials in these particular gears, the technology behind &quot;strain-wave&quot; &#x2F; &quot;harmonic drive&quot; gears used in a lot of precision robots is very very cool. Parts of the gear set are actually flexible yet you get very smooth* motion with negligible backlash out of them!<p><a href="http:&#x2F;&#x2F;www.harmonicdrive.net&#x2F;technology" rel="nofollow">http:&#x2F;&#x2F;www.harmonicdrive.net&#x2F;technology</a><p>(EDIT: We commented at same time, so see also olivierlacan&#x27;s commented video! <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bzRh672peNk" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bzRh672peNk</a> )<p>* - (Compared to more typical gears, and the cogging you get out of them. There are other issues with these gears the controls guys have to deal with when you start going for really high precision motion, but I don&#x27;t want to seem like I&#x27;m knocking them as they do solve a lot of problems in a really clever way!)

&gt; Metallic Glass Gears Make for Graceful Robots Space Gears Harmonic drive Bulk metallic glass, a metal alloy, doesn’t get brittle in extreme cold.<p>What kind of sentence is that?

Why do robots rely so much on gears? There is no gear in the animal kingdom, and yet their limbs are vastly more energy efficient and agile, aren&#x27;t they?

&gt;“Mass producing strain wave gears using BMGs may have a major impact on the consumer robotics market,” Hofmann said. “This is especially true for humanoid robots, where gears in the joints can be very expensive but are required to prevent shaking arms. The performance at low temperatures for JPL spacecraft and rovers seems to be a happy added benefit.”<p>Highly unlikely. Teflon (PTFE) can be injection moulded and is self lubricating and probably cheaper although it still costs and arm and a nut. Also the flex spline is one of the cheapest parts of a harmonic drive- the elliptical bearing is more expensive.<p>There are also other reasons not to use harmonic drives. Their efficiency usually isn&#x27;t as good as advertized and is often worse than other gearsets.

Shouldn&#x27;t this be &quot;Glassy Metal Gears&quot;, instead of the opposite? They say they heat it up to get rid of the crystals, then somehow cool it without allowing them to form, leading to a metal in an amorphous solid form like that glass takes on when it cools.

since there are robotics people in here, would someone mind linking me to videos or blogs about tearing down&#x2F;talking about the motors and drivers used in cutting edge robotic arms such as those used in the automotive industry?