Day: May 3, 2023

Barcodes Enter The Matrix In 2027

May 3, 2023 by 80 Comments

Beep. We’ve come a long way since June 26, 1974 when the first bar code was scanned at a grocery store in Troy, Ohio. That legendary pack of Juicy Fruit proved that even the smallest of items could now carry numbers associated with inventory and price.

By now, we’re all too familiar with this sound as self-checkouts have become the norm. Whereas you yourself could at one time literally check out during the transaction, you must now be on your toes and play find the bar code on every item.

What does the consumer gain from the bar code today? Practically nothing, except the chance to purchase, and potentially return, the item without too much hassle. Well, the non-profit outfit that runs the bar code world — GS1 US — wants to change all that. By 2027, they are confident that all 1D bar codes will be replaced with 2D bar codes similar to QR codes. Why?

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China's Chang'e-4 mission made the first-ever landing on the far side of the Moon in 2019. (Credit: Xinhua/Alamy)

Moon Mission Failures, Or Why Are Lunar Landings So Hard?

May 3, 2023 by 41 Comments

Given the number of spacecraft (both crewed and uncrewed) that touched down on the Moon during the Space Race it’s sometimes hard to imagine why today, with all our modern technology, our remotely operated vehicles seem to have so much trouble not smashing themselves to bits on the regolith surface.

This is the focus of a recent article in Nature that explores the aspects which still make soft landings on our closest space body so much harder than the tragic lithobraking as most recently demonstrated by ispace’s M1 lander.

So far only three entities have successfully landed a craft on the Moon’s surface: the government-funded space agencies of the US, USSR, and China. Of them, only China managed to do so on their first try in 2013 (Chang’e-3), and again in 2019 on the far side of the Moon (Chang’e-4). What is the toughest part about a Moon landing is not to get near the Moon, but it’s about getting close to the surface without getting lost. Since there are no navigation satellites beyond those you put up before the landing, and a lot of Moon dust that will be kicked up by any landing rocket engines, it can be tough to gauge one’s exact location and distance to the surface.

In the case of the ispace lander it would appear that it tragically ran out of propellant before it could safely touch down, which is another major concern. Both the US and USSR would smash Moon landers into its surface until the first successful landing in 1966, which makes the manned touchdown by Apollo 11 in 1969 even more impressive.

Kerfmeter Measures Laser Cutter Kerf Allowances On The Fly

May 3, 2023 by 21 Comments

Nothing beats a laser cutter and a sheet of Baltic birch plywood or MDF when it comes to making quick, attractive enclosures. Burning out all the pieces and fitting them together with finger joints is super satisfying — right up until you realize that you didn’t quite get the kerf allowance right, and your pieces don’t fit together very nicely. If only there was a way to automate kerf measurement.

There is, in the form of Kerfmeter. It comes to us by way of the lab of [Patrick Baudisch] at the University of Potsdam, where they’ve come up with a clever way to measure the kerf of a laser cutter right during the cutting session. With the Kerfmeter mounted directly to the laser cutter head, a small test artifact based on an Archimedean spiral is cut into a corner of the workpiece. Pins on a small motor engage with the object and turn it until it jams in its hole; the wider the kerf, the greater the angle. Once the kerf is calculated, the rest of the design can be dilated by the proper amount to achieve a perfect fit. The video below shows it better than words can explain it.

What we like about this is its simplicity — all it involves is a motor and a microcontroller, plus a little software. It seems much faster than using a traditional kerf gauge, not to mention more precise. And while it does use up a little bit of material, the test pattern is really pretty small, all things considered. Seems like a reasonable trade-off to us. Still, if you want to figure out your kerfs the old-fashioned way, we’ve got you covered.

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