Laser And Webcam Team Up For Micron-Resolution Flatness Measurements

March 16, 2023 by Dan Maloney 36 Comments

When you want to measure the length, breadth, or depth of an object, there are plenty of instruments for the job. You can start with a tape measure, move up to calipers if you need more precision, or maybe even a micrometer if it’s a really critical dimension. But what if you want to know how flat something is? Is there something other than a straightedge and an eyeball for assessing the flatness of a surface?

As it turns out, there is: a $15 webcam and a cheap laser level will do the job, along with some homebrew software and a little bit of patience. At least that’s what [Bryan Howard] came up with to help him assess the flatness of the gantry he fabricated for a large CNC machine he’s working on.

The gantry arm is built from steel tubing, a commodity product with plenty of dimensional variability. To measure the microscopic hills and valleys over the length of the beam, [Bryan] mounted a lens-less webcam to a block of metal. A cheap laser level is set up to skim over the top of the beam and shine across the camera’s image sensor.

On a laptop, images of the beam are converted into an intensity profile whose peak is located by a Gaussian curve fit. The location of the peak on the sensor is recorded at various points along the surface, leading to a map of the microscopic hills and valleys along the beam.

As seen in the video after the break, [Bryan]’s results from such a quick-and-dirty setup are impressive. Despite some wobblies in the laser beam thanks to its auto-leveling mechanism, he was able to scan the entire length of the beam, which looks like it’s more than a meter long, and measure the flatness with a resolution of a couple of microns. Spoiler alert: the beam needs some work. But now [Bryan] knows just where to scrape and shim the surface and by how much, which is a whole lot better than guessing. Continue reading “Laser And Webcam Team Up For Micron-Resolution Flatness Measurements” →

Hackaday Links: March 12, 2023

March 12, 2023 by Dan Maloney 38 Comments

With a long history of nearly universal hate for their products, you’d think printer manufacturers would by now have found ways to back off from the policies that only seem to keep aggravating customers. But rather than make it a financially wiser decision to throw out a printer and buy a new one than to buy new ink cartridges or toners, manufacturers keep coming up with new and devious ways to piss customers off. Case in point: Hewlett-Packard now seems to be bricking printers with third-party ink cartridges. Reports from users say that a new error message has popped up on screens of printers with non-HP cartridges installed warning that further use of the printer has been blocked. Previously, printers just warned about potential quality issues from non-HP consumables, but now they’re essentially bricked until you cough up the money for legit HP cartridges. Users who have contacted HP support say that they were told the change occurred because of a recent firmware update sent to the printer, so that’s comforting.

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FDM Printing With Resin Update

March 4, 2023 by Al Williams 15 Comments

[Proper Printing] is at it again. He’s trying to perfect his hybrid printer that works like an FDM printer but uses UV-curable resin gel instead of filament. You can see the latest update video below. If you missed our take on his early attempts, you might want to catch up with those earlier videos first.

The latest update brings a new nozzle, an improved light source, and changes to the formula of the resin. The nozzle and light source improvements hinge on conical lenses that convert the laser beams from a spot to a ring. The initial nozzles looked like the business end of a syringe, but this wasn’t very stable. The new video shows a conventional nozzle which also had some issues. This resulted in a custom-made nozzle that solved all the issues with the conventional nozzle and the syringe tips.

The resin formula is particularly crucial. The second attempt used resin with glass beads to give thickness. That wasn’t without problems, though, so it was switched this time with fused silica, as suggested by some comments on a previous video. They also used aggressive mixing and air removal. The consistency of the previous resins was that of a paste, but according to the video, the new mixture is more like a gel.

At some point, things started going badly. There were several equipment failures. Exasperated, he was ready to give up and was editing the video when he had an epiphany. We’re glad he didn’t give up because the new results are pretty impressive.

These printers remind us of some strange laser CNC. It also reminds us a little of people curing resin outside of the normal print process.

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Drilling Glass With Femtosecond Lasers Just Got Even Better

February 16, 2023 by Lewin Day 48 Comments

Glass! It’s a finicky thing. Strong as hell, yet chip it and glance at it the wrong way, and you’re left with a bunch of sharp rubbish. It’s at once adored for its clarity and smoothness, and decried for how temperamental it can be in the case of shock, whether mechanical, thermal, or otherwise.

If you’ve ever tried to drill glass, you’ll know it’s a tough errand. To do so without cracking it is about as likely as winning the lottery on Mars. Even lasers aren’t great at it. However, a research team from France has developed a new technique that uses femtosecond lasers to drill microscopic holes in glass with a minimum of tapering and no cracking! Brilliant, no?
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Two goniometers sit on a table. One is an open wooden box with a long piece of plywood along the bottom. A laser distance finder rests on the front edge and a printed angle scale has been attached to the back side of the box. To the right of this box is a much smaller goniometer made from an orange pipe cap with a small strip of paper serving as the angle scale inside the interior edge. It is attached to a wooden handle that looks vaguely like a V. A laser pointer can be inserted from the bottom where a hole has been drilled through the wood.

Goniometer Gives You An Edge At Knife Sharpening

February 9, 2023 by Navarre Bartz 11 Comments

Sometimes you absolutely, positively need to know the angle of the cutting edge on a knife. When you do, the best tool for the job is a laser goniometer, and [Felix Immler] shows us three different ways to build one. (YouTube)

The underlying principle of all three of these builds is to project reflected laser light off a knife blade onto a scale going from 0-45˚. [Immler] shows a basic demonstration of this concept with a hinge toward the beginning of the video (after the break). Blades with multiple bevels will reflect light to each of the appropriate points on the scale.

The simplest version of the tool is a printed PDF scale attached to a wooden box with a hole for the blade to pass through. The next uses a large pipe end cap and a drilled-out piece of wood to create a more manageable measuring tool. Finally, [Immler] worked with a friend to design a 3D printed goniometer with differently-sized adapters to fit a variety of laser pointers.

Now that you’re ready to precisely sharpen your blades, why not sharpen this guacamole bot or try making your own knife from raw ore?

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Turns Out, Lightning Can Strike Twice, With A Little Help

January 17, 2023 by Al Williams 19 Comments

Few things are more impressive than a lighting strike. Lightning can carry millions of volts and while it can be amazing to watch, it is somewhat less amazing to be hit by lightning. Rockets and antennas often have complex lightning protection systems to try to coax the electricity to avoid striking where you don’t want it. However, a European consortium has announced they’ve used a very strong laser to redirect lightning in Switzerland. You can see a video below, but you might want to turn on the English closed captions.

Lightning accounts for as many as 24,000 deaths a year worldwide and untold amounts of property and equipment damage. Traditionally, your best bet for protection was not to be the tallest thing around. If the tallest thing around is a pointy metal rod in the ground, that’s even better. But this new technique could guide lightning to a specific ground point to have it avoid causing problems. Since lightning rods protect a circular area roughly the radius of their height, having a laser that can redirect beams to the area of a lightning rod would allow shorter rods to protect larger areas.

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DIY Fiber Laser Adds Metal Cutting To The Mix

January 13, 2023 by Dan Maloney 23 Comments

Sadly, the usual CO₂-powered suspects in the DIY laser cutter market are woefully incapable of cutting metal. Sure, they’ll cut the heck out of plywood and acrylic, and most will do a decent job at engraving metal. But cutting through a sheet of steel or aluminum requires a step up to much more powerful fiber laser cutters. True, the costs of such machines can be daunting, but not daunting enough for [Travis Mitchell], who has undertaken a DIY fiber laser cutter build that really caught our eye.

Right off the bat, a couple of things are worth noting here. First — and this should be obvious from the fountains of white-hot sparks in the video below — laser cutters are dangerous, and you should really know what you’re doing before tackling such a build. Second, just because [Travis] was able to cut costs considerably compared to a commercial fiber laser cutter doesn’t mean this build was cheap in absolute terms — he reports dropping about $15,000 so far, with considerable ongoing costs to operate the thing.

That said, there doesn’t appear to be anything about this build that anyone with some experience building CNC machines wouldn’t be able to tackle. The CNC side of this is pretty straightforward, although we note that the gantry, servos, and controller seem especially robust.

The laser itself is an off-the-shelf machine, a Raycus RFL-C1000 fiber laser and head that packs a 1,000-Watt punch. There’s also the required cooling system for the laser, and of course there’s an exhaust system to get rid of the nasty fumes.

All that stuff requires a considerable investment, but we were surprised to learn how much the consumables cost. [Travis] opted for bottled gas for the cutter’s gas assist system — low-pressure oxygen for carbon steel and high-pressure nitrogen for everything else. Refills are really pricey, in part because of the purity required, but since the proper compressor for the job is out of the budget for now, the tanks will have to do. And really, the thing cuts like a dream. Check out the cutting speed and precision in the video below.

This is but the first in a series of videos that will detail the build, and if [Travis] thought this would whet our appetites for more, he was right. We really haven’t seen many DIY fiber laser builds, but we have seen a teardown of a 200-kW fiber laser that might tickle your fancy.

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