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”→
Recently [Big Clive], everyone’s favorite purveyor of anything electronic that’s dodgy, cheap, cheerful, decidedly crispy or any combination thereof, got sent a very dead external power supply unit. Being clearly a third-party PSU with poorly written and many (likely not truthful) safety approval markings on its label, this PSU had the dubious honor of having destroyed a Microsoft Surface computer as well as the monitor that was connected at the time.
In [Clive]’s video (also embedded after the break) the black and very crispy board is examined, showing a wealth of vaporized traces and plenty of soot. What’s however most fascinating is the failure mode: instead of something obvious like e.g. the main transformer between the primary and secondary side failing, here it would seem that an inductor (see heading image) on the secondary side had its insulation rubbed off and shorted on a nearby heatsink. A heatsink that just happened to be also electrically connected on the primary (mains-level) side.
Judging by the former owner’s report and aftermath, this led to a very sudden and violent demise of the PSU, with mains power very likely making its way into the unsuspecting Surface system and connected monitor. The number of ‘very nope’ design decisions made in this PSU are astounding, and a lesson for both aspiring EEs and anyone considering getting a ‘cheap’ third-party replacement PSU.
People always tell us that their favorite part about using a computer is mashing out the exact same key sequences over and over, day in, day out. Then, there are people like [Benni] who would rather make a microcontroller do the repetitive work at the touch of a stylish USB peripheral. Those people who enjoy the extra typing also seem to love adding new proprietary software to their computer all the time, but they are out of luck again because this dial acts as a keyboard and mouse so they can’t even install that bloated software when they work at a friend’s computer. Sorry folks, some of you are out of luck.
Rotary encoders as computer inputs are not new and commercial versions have been around for years, but they are niche enough to be awfully expensive to an end-user. The short BOM and immense versatility will make some people reconsider adding one to their own workstations. In the video below, screen images are rotated to get the right angle before drawing a line just like someone would do with a piece of paper. Another demonstration reminds of us XKCD by cycling through the undo and redo functions which gives you a reversible timeline of your work.
The Microsoft Surface Pro 3 is a neat little tablet, and with an i7 processor, a decent-resolution display, and running a full Windows 8.1 Pro, it’s the closest you’re going to get to a desktop in tablet format. Upgrading the Surface Pro 3, on the other hand, is nigh impossible. iFixit destroyed the display in their teardown, as did CNET. [Jorge] wanted to upgrade his Surface Pro 3 with a 1 TB SSD, and where there’s a will there’s a way. In this case, a very precise application of advanced Dremel technology.
Taking a Surface Pro 3 apart the traditional way with heat guns, spudgers, and a vast array of screwdrivers obviously wasn’t going to work. Instead, [Jorge] thought laterally; the mSSD is tucked away behind some plastic that is normally hidden by the small kickstand integrated into the Surface. If [Jorge] could cut a hole in the case to reveal the mSSD, the resulting patch hole would be completely invisible most of the time. And so enters the Dremel.
By taking some teardown pictures of the Surface Pro 3, printing them out to scale, and aligning them to the device he had in his hand, [Jorge] had a very, very good idea of where to make the incision. A Dremel with a carbide bit was brought out to cut into the metal, and after a few nerve-wracking minutes the SSD was exposed.
The only remaining task was to clone the old drive onto the new one, stuff it back in the Surface, and patch everything up. [Jorge] is using some cardboard and foam, but a sticker would do just as well. Remember, this mod is only visible when the Surface kickstand is deployed, so it doesn’t have to look spectacular.
Thanks [fridgefire] and [Neolker] for sending this in.
[HyPe] over at the Natural User Interface Group developed this concept as part of his Master’s Degree in Industrial Design. This suitcase sized projector and computer allows people to have a 60″ multitouch screen available wherever there is a large enough surface. The current software is designed for ad-hoc meetings about large-scale construction plans. The rolling case includes a short-throw projector and webcam. Just set it on top of your work surface, lift the lid, and it’s ready to go.
[Johnny Lee]’s colleague [Paul Dietz] has done some interesting work using interactive tables. He’s specifically researched how to determine how full a drink glass is. In the video above, he’s using Microsoft’s Surface, but this technique should work with any IR camera based multitouch table. Determining the drink level requires custom glassware that has a small prism inside. When the liquid level is above the prism, light passes through, but when it’s below the top it reflects more IR light back into the table. Using this information, restaurant staff could serve drinks in a more efficient manner.
If you’ve got an extra grand laying around, you can pre-order one of [nortd]’s touchkits. It features a unique custom made acrylic screen with a crap ton of IR LEDs embedded in it. An included IR camera provides the input and a projector (you get to supply your own) is used to light the surface. We mentioned this in our multitouch roundup and you can find a video of it embedded after the break.