Laser Spirograph

laser-spirograph

Here’s a weekend junk bin project if we’ve ever seen one. [Pat] used a quartet of computer fans to make his laser Spirograph. Deciding to try this simple build for yourself will run you through a lot of basics when it comes to interfacing hardware with a microcontroller. In this case it’s the Arduino Nano.

The Spirograph works by bouncing a laser off of mirrors which are attached to the PC fans. When the fans spin the slight alignment changes cause the laser dot to bob and weave in visually pleasing ways. You can catch twenty minutes of the light show in the clip after the break.

Three of the fans have mirrors attached, the housing of the fourth is used to host the laser diode and make assembly easier. A TC4469 motor driver is used to connect the fans to the Arduino. The light show can be manually controlled by turning the trio of potentiometers which are read using the Arduino’s ADC.

If you manage your way through this build perhaps you’ll move on to a setup that throws laser light all over the room.

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3D Scanner Made In A Day

diy-3d-scanner

The LVL1 Hackerspace held a hackathon back in June and this is one of the projects that was created in that 24-hour period. It’s a 3D scanner made from leftover parts. The image gives you an idea of the math used in the image processing. It shows the angular relations between the laser diode, the subject being scanned, and the webcam doing the scanning.

The webcam is of rather low quality and one way to quickly improve the output would be to replace it with a better one. But because the rules said they had to use only materials from the parts bin it worked out just fine. The other issue that came into play was the there were no LCD monitors available for use in the project. Because of that they decided to make the device controllable over the network. On the right you can see a power supply taped to the top of a car computer. It connects to the laser (pulled out of a barcode scanner which produces a line of red light) and the turntable. A Python script does all of the image processing, assembling each slice of the scan into both an animated GIF and an OBJ file.

[Thanks Nathan]

One Method Of Fabricating Translucent Faceplates

laser-cut-translucent-panel-covers

Enclosures are the bane of electronics engineers (or so says [Dave Jones] of the EEVblog and The Amp Hour). But fabricating a case that looks great has been getting easier lately. [Eric Forkosh] produced this professional-looking translucent face plate with a minimum of effort. He found a way to use a laser cutter to etch icons in acrylic.

Admittedly, this is not very involved. But just look at the quality he achieved. The secret to his success (aside from having a quality laser cutter on hand) is to use high-temperature spray paint. The acrylic is coated in paint and allowed to dry before heading to the laser cutter. By using the rasterize setting under low power he kills two birds with one stone; the paint is etched away while the acrylic is left a little bit rough to act as a diffuser for LEDs behind the panel. [Eric] cautions against using regular spray paint. In his write up he shows off the unsightly results of doing so.

This makes a great addition to some of the case options out there. One that we have been keeping our eye on is the Sick of Beige initiative being spearheaded by [Ian Lesnet].

More Details About Laser Cut Gingerbread Houses

Members of Sector67 tried their hands at laser cut gingerbread houses. The Madison, Wisconsin based hackerspace is using the tabbed box method of assembly for the corners of the structure. They’ve also put up a bunch of information about laser settings and published the recipe used to mix up a sheet of gingerbread. This quite a bit more info than was provided with the project we saw a couple of weeks back.

The initial designs were made in Inkscape and then transferred to Corel Draw before heading to the cutter. They’ve got a 150W machine and found that a speed of 15 worked well when the speed was set to 100, with a corner speed of 60. The raw dough was rolled out to 1/8″ thickness. Possibly the best tip coming out of Sector67 is to lay 1/8″ dowels on either side of the dough. This way the rolling pin will stop when it hits the dowels resulting in the best possible uniform thickness. As reported in the previous project the odor generated while cutting is not the most pleasant. But we love the fusion of lasers with the age old process of building with cookies and decorating with candy.

Converting A Chinese Laser Cutter To Work With Mach3

laser

Like most of us, [Chris] has pined over the very, very inexpensive Chinese laser cutters available on eBay for a while now. When most of us disregarded these machines due to their inability to work with the file formats commonly used with laser cutters, [Chris] took the plunge. He was a might disappointed the included software didn’t allow him to use his machine with Mach3 CNC software, so he replaced the included electronics board with one of his own design, giving him all the features of a more expensive laser cutter at a low, low Chinese eBay auction price.

The laser cutter [Chris] bought came with the moshidraw software and controller board that according to one auction can only use BMP, JPEG, WMF, EMF, and PLT files.Wanting a board that can use more common file formats such as PDF and DWG, [Chris] built his own board to communicate with his Mach3 software.

From what we can tell, the new board works with off-the-shelf Pololu stepper drivers and is a complete drop in replacement for the moshidraw board. He’s still finalizing the design, but when the layout, BOM, and schematic are finalized, [Chris] will be putting the files up for everyone to copy. Wonderful piece of work, [Chris].

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Design A Gingerbread House In CAD, Then Cut Pieces With A Laser

This is one of those ideas that’s so simple we can’t believe we haven’t heard of it before now. [Johan von Konow] is upping his holiday decorating game this year by designing his Gingerbread House in CAD and cutting it out on a laser cutter. If designed well this will easily allow you to increase the complexity of your design by orders of magnitude.

We remember making Gingerbread Houses with mom when we were little. She would bake a sheet of gingerbread, then pull out stencils she had made from file folders to carefully cut the walls and roof of the houses. But these were the homesteading equivalent of candy construction — one room consisting of four walls and two roof pieces. [Johan’s] design uses roofs with multiple pitches, dormers, and an entryway off the front of the main building. Quite impressive!

He mentions a few things to keep in mind. The gingerbread should be an even thickness for best results. You’re also going to want to plan for ventilation during cutting and give up the idea that you might eat the house when the holidays are over. The cutting process creates quite a stink and leaves a horribly burnt taste in the baked goods. Of course you could always cut out templates and use a knife when working with food.

Laser Charged Glowing Display

Here’s one of the best takes on a glowing display that we’ve ever seen. Currently [H] is using his creation as a fuzzy clock, but it is certainly capable of displaying just about any messages.

The project uses a wheel of luminous paper as the display surface. This has a glow-in-the-dark quality to it which can be charged up using a bright light source. In this case a UV laser diode was used. This is perhaps the best possible source as its intensity will allow for very quick charging. The innovation here is the use of a second disk as a stencil. Look closely in the image above and you will see that the laser diode is mounted perpendicular to the display surface itself. A mirror reflects — and we believe slightly spreads — the laser dot. It then passes through a cut-out on the black wheel which is shaped as the desired character. As you can see in the video after the break, this results in a crisp and clear glowing letter.

Compare this project to the one that moves the diode itself like a plotter and we think you’ll agree this is a simpler implementation which still looks great!

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