iAM Marketplace, a new storefront for used industrial 3D printers, materials, and spare parts, just launched today. It's mash-up of Stratasys subsidiaries and acquisitions (AM Marketplace, iSquared, Forward AM, Nexa3D), and, in addition to pre-owned hardware, there's a strong focus materials (filaments, pellets, powders) from a range of makers and custom material development. Correction: a previous version incorrectly reported that used non-stratasys machines would be coming to the platform.

Formlabs just published a compelling customer story on 67 Designs, which makes all types of holders using in-house SLS printing as its core production strategy. While competitors wait on slow, costly molds, this "Made in the USA" shop is already shipping final parts, cost-effectively cranking out units by the thousands. The agility is key: When Apple changes an iPad's dimensions, 67 Designs just tweaks the digital file and hits "print," dodging inventory graveyards and leaving old-school tooling in the dust.

a Goldsmiths’ Award-winning gold spinning top (yes, solid gold), lovingly birthed by Cooksongold’s Additive Manufacturing Department a few years back. Watch as cutting-edge 3D printing tech turns obscene amounts of precious metal and a few red jewels into a toy. We don’t know who ordered it, and frankly, we don’t care—because watching molten gold get precision-printed is as weirdly satisfying as power-washing videos, only shinier and far more expensive.

AutoCAD has you covered against ill-thought-out object deletions with its "oops" command. Say you delete an object or group of objects, continue working, and then realize that, actually, that deleted object would come in handy after all. Typing "oops" into the command line brings it back without overriding what you've done since. Is it the most honest feature name ever? Possibly.

Today's Tuesday Tips with Frank post on the AutoCAD blog covers "oops" and other commands in more detail.

Designer Ezra Feldman (EYF Design) has hit a home run with this clever Baseball Glove Lamp. It's a major league steal at just $3 for the STL file for subscribers on Thangs, letting you print as many as you need for your personal roster. You 3D print the translucent ball, insert a standard disc LED, and mount the 3D printed glove. The project is an easy multicolor print and a guaranteed conversation piece.

It's a simple question, rooted in some coverage we ran this week about a study into the emission levels in school classrooms with running 3D printers. The survey itself was relatively inconclusive about any harms, finding that while printers are responsible for the majority of recorded harmful emissions, it's still below recognized harmful levels. Regardless, it reinforces our position that an enclosure is a smart addition to your printing set up.

Former USA Road National Champion Alex Howes is one of the first to lace up (well, strap in) the Lore Three Performance Series, which are cycling shoes so advanced they’re custom 3D printed to your feet. Seen flaunting his personalized pair at Big Sugar Gravel, Howes says he’s no investor, just a fan with happy arches. After years of WorldTour woes (snapped dials, misfit insoles, and rubbing), Howes says the "Morphic" carbon-fiber produces better power transfer in a perfect fit.