Camera Adapter For A Microscope

camera-adapter-for-stereo-microscope

[Steve] really has a nice microscope setup in his lab now that he built a video camera adapter for his stereo microscope. The image above shows the magnified view of the circuit board on the LCD screen behind it. This lets him work without needing to be in position to look through the eye pieces. The hack is a perfect complement to the custom stand he fabricated for the scope.

The camera attachment can be seen attached to the right lens of the scope. It’s an old security camera which he already had on hand. The stock lens wasn’t going to bring the picture into focus, but he had some different optics on hand and one of them fit the bill perfectly. The rest of the project involves fabricating the adapter ring on his lathe. It slips perfectly over the eyepiece and even allows him a bit of adjustment to get the focal length right. The best view of this is shown off in the video after the break.

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PCB Stencils For $200

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There’s some really cool stuff to find if you wander around a Michaels craft shop or Hobby Lobby long enough. Recently, [Ben] picked up a craft cutter – a small vinyl cutter-like device meant for scrapbooking and other crafty endevours. He’s using this machine to create solder paste stencils that are better than any laser cut stencil he’s used before.

Like a build we’ve seen before, [Ben] is using a desktop-sized vinyl cutter, the Sihouette Portrait,  with 4 mil Mylar. After converting the relevent layers of a Gerber file into .SVG files, [Ben] loaded up Robocut to cut very, very small holes in his solder stencil. The results are great; much better than a laser would cut Mylar, and good enough to apply paste to a few hundred boards at least.

While [Ben] is using his stencils to apply solder paste, we’re wondering if a similar process could be used to apply a UV-curing solder mask to home-fabbed boards. That would allow for some very professional-looking boards to be produced with a turnaround time of just a few hours.

Hard Drive Centrifuge For Sensitizing Copper Clad Boards

hdd-to-apply-light-sensitive-ink

We would wager that most of the home etched PCB projects we see around here use the toner transfer method. But the next most popular technique is to use photosensitive ink which resists the etching acid once it has been exposed to light. Most people buy what are called pre-sensitized boards, but you can also get ink to make your own. [Jardirx] does this, and uses an old hard drive to apply an even layer of the light-sensitive ink.

The narration and subtitles of the video found after the break are both in Portuguese, but it’s not hard to figure out what’s going on here. He begins by using double-sided foam tape to secure the piece of copper clad board to the hard drive platters. You’ll want to center it as best as you can to keep the vibrations to a minimum. From there [Jardirx] applies a coating of the ink using a brush. The image above is what results. So as not to get ink everywhere, he then lowers a soda bottle with the bottom cut off to catch the excess. Power up the drive for a few seconds and the board will have a nice even layer ready for a trip through a UV exposure box.

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Human Powered Emergency Cell Phone Charger

Emergency-human-powered-cell-phone-charger

Power outage? For the average citizen it’s very easy to take electricity for granted. Go a few hours or more without it though, and you’ll suddenly be reminded just what a luxury it is. During an emergency situation, sometimes you have to come up with alternative methods to get the job done. This human powered cell phone charger is a great example.

Using just a few ordinary around the house items, [The King of Random] turned a cordless electric drill into a human powered electrical generator. If the drill is run in reverse and cranked by hand, the generated energy can be transferred through the battery terminals to a connected device.  So, he cut a USB charger cable in half and wired it up to the terminals to be able to charge his cell phone. Some yarn, a salad fork, a mixing beater, a scrap 2″x4″, some aluminum foil, and scotch tape were the only other materials he used. Using this technique, a totally dead phone battery was charged in around 3 hours.

Remember that this method is only intended to be used in an emergency, not as every day practice. Using these methods could potentially overheat or damage your gear, so be careful.

Check out the MacGyver worthy video tutorial after the break.

[via Neatorama]

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Bending Materials With A Simple Hot Wire Forming Tool

bending-with-a-hot-wire-former

Regular reader [RoadWarrior222] has watched as we’ve featured several projects that show how to bend acrylic. But so far he hasn’t seen us cover his favorite technique developed by [Dale A. Heatherington] which uses a hot wire forming tool to make precise bends. The tool is simple to use plus it’s cheap and easy to build. It’s a great choice if you don’t have a heat gun, and it may be possible to make cleaner bends than other techniques.

The business end of the bending tool is the red-hot Nichrome wire running through the aluminum channel. That channel is used to protect the MDF and act as a spacer so that the wire doesn’t touch the acrylic. On the near side the wire is anchored with a screw, but on the far end it is kept taught by including a spring. The wire heats up as it is connected to a 12V battery, but since the heating is cause by the wire’s resistance it will only get red-hot in between the alligator clips providing power. To make sure your bends will be perpendicular to the edge of the acrylic there’s an aluminum guide strip on one side of the MDF platform.

You can salvage Nichrome wire from an old hair dryer. If you have any left over it’s great for other projects like building a CNC hot-wire cutter.

Taking The Pain Out Of Making Custom Eagle Parts

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Cadsoft’s Eagle is a great tool for the independent maker. It’s a relatively easy to use PCB layout program with a ton of part libraries available for just about any project. If you’re using a part this isn’t included in these libraries, though, creating them by hand is a pain. [Dave] sent in a project he’s been working on that makes parts for Eagle with a Perl script, allowing for easy creation of custom parts that aren’t included in any library.

One thing that’s really convenient for custom Eagle parts is that most components are DIPs or some sort of leaded SMD component. [Dave]’s script takes the dimensional data from any chip’s datasheet and creates a custom outline for each part. The inputs and outputs can also be ripped directly from the datasheet and assigned to the footprint, making for a relatively automated process that creates custom parts in Eagle. Now for someone to use this script with a little OCR to make a ‘create Eagle part from PDF’ app…

Modifying A Printer For PCB Fabbing

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The migraine-inducing image above is the product of [Rupert Hirst]’s attempts at home PCB fabrication. He’s using the toner transfer method – printing a circuit on a piece of transparency sheet with a laser printer, setting it on a piece of copper clad board, and sending the whole assembly through a laminator. It’s a fairly straightforward process, but if you can’t run a transparency sheet through a printer multiple times your etch resist won’t hold up too well. Of course the transparency sheet must be aligned each time it goes through the printer, so [Rupert] came up with a modification that ensures laser toner goes only where it’s supposed to.

[Rupert] picked up a Samsung ML-2165W laser printer for his PCB fab shop, but printing the same image multiple times on the same transparency sheet would result in unusable masks. This problem was fixed with a few plastic shims used to hang door frames and a card stock tray that ensures the transparency sheet goes through the printer the same way every time.

We saw [Rupert]’s homebrew PCB fabrication process a few weeks ago when he sent in his six channel floppy drive MIDI synth. In his build video, [Rupert] demonstrated what is possibly the cleanest toner transfer PCB we’ve seen to date. You can check out his etching process in the video after the break.

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