Never Pay More Than $10 For A Projector Mount

September 28, 2012 by 8 Comments

[Lou] needed to mount his projector to finish up his home theater. But he was rather put off by the cost of commercial solutions. He ended up building his own projector mount for about ten bucks. The technique reuses some scrap metal and sources connectors from the hardware store. If your projector will be mounted flat to the ceiling we think this will work just as well for you as it did for him.

To the left we get a good look at the two parts which make up the mounting bracket. [Lou] is reusing a metal warning sign. One large piece is attached to the back portion of the projector and hangs over the end about a half-inch. On the front there is a tab with a slot in it made out the same sign. The slot accepts the head of a three-inch drywall screw. There are two holes in the rear piece which also receive screws. Once the projector is in place the screws can be adjusted to achieve the proper projection angle. [Lou] does a full walk through of the project in the video after the break.

This goes perfectly with the $50 projection screen that he built.

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16×8 Pixel Laser Projector

September 14, 2012 by 4 Comments

[Michiel] gave us a little shout-out by drawing the Hackaday logo with his recently completed 16×8 pixel laser projector. It uses a spinning set of mirrors mounted at slightly different angles to redirect the path of the red laser diode.

The projector is driven by an Arduino. To give it more than just a hard-coded existence [Michiel] included an Xbee module. This lets him connect to it with a computer in order to stream messages. One of the demo videos linked in his project log shows the web interface he coded which will push a message typed in the submission form out to the projector where it is scrolled like a marquee.

This type of spinning display is one of a few common methods for making laser projectors. In the image above you can see the optical sensor which is used to sync the diode with the spinning mirrors, each of which is responsible for a different row of pixels. He lists off several things that he learned when working on the project. We think the most important is the timing issues which go into something like this.

Keeping An Old 8mm Projector Alive With High-power LEDs

May 24, 2012 by 51 Comments

There’s a certain mystique about old home movies and 8mm film; whether it’s footage from a family gathering from 40 years ago or a stop-motion animation you made when you were 12, there’s an immediacy for film that the VHS tapes from your family’s first camcorder can’t match. [Teslas Moustache] has been getting into 8mm cameras and projectors, so when he came across a 8mm/super 8 projector that needed a bulb, he knew he had a worthwhile project on his hands.

To replace the burnt-out and very expensive to replace incandescent bulb, [Teslas] sourced a very bright star LED from Jameco. This 1 Watt LED puts out more than enough light to project a frame of film onto a screen and fortunately doesn’t get as hot as the stock bulb.

To power the LED, [Teslas] used a cell phone charger powered from the 120 VAC incandescent socket to supply the requisite 5 Volts at 1 Amp (Ohm’s Law works on coffee) power for the LED. Right now, there’s still the matter of fabricating a nice enclosure to mount the LED and charger in the bulb socket, but once [Teslas] figures that out, he’ll have a very nice 8mm projector on his hands.

3D Printer With Insane Accuracy Uses A DLP Projector

April 5, 2012 by 107 Comments

After years of work, [Junior Veloso] is finally getting his 3D printer project out to the public. Unlike the Makerbots and repraps we usually see, [Junior]’s printer uses light-curing resin and a DLP projector to build objects with incredibly fine detail.

One highlight of [Junior]’s project is the development of low-cost resins. Normally, light curing resins are extremely expensive, but [Junior] is actively trying to get the price of resin down to $150 USD per kilogram. A quick back-of-the-wolfram calculation tells us you should be able to print about 7-800 cubic centimeters with a kilogram of resin. It’s much more expensive than plastic filament used in other 3D printers, but that’s the price you pay for quality.

There’s a very popular Indiegogo campaign that is trying to raise money to mass produce the resin and some components of this kit. We’re not impressed with the rewards for this campaign – $59 for a .PDF description of the printer without any dimensions, $159 for a BOM, dimensions and the formula to make your own resin, and $400 for the closed-source software [Junior] devleoped – but hopefully this Indiegogo gets cheap resin out onto the market. There’s a short FAQ about this printer, so we’ll leave our readers to tactfully discuss the merits of this printer in the comments below.

You can check out the process of printing a remarkably detailed alien skull in the video after the break.

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Baby’s First Star Light Projector And A Foil Slip Ring

March 22, 2012 by 7 Comments

For a newborn, everything is magical; a lack of object permanence means everything is new, wonderful, and novel. What then, could be better than a projected star field circling an infant’s room, gently sending them to sleep?

[Pete] was inspired by this earlier starlight projector that projects a rotating star field onto the walls and ceiling of a nursery. Instead of a rather loud servo, [Pete] used a quiet 12 Volt gear motor that spins the star field at 5 RPM. Like the previous build, a LED was used but [Pete] found a color-changing RGB LED that automatically shifts colors.

The shaft of [Pete]’s gear motor is tiny, and unlike the servo, there’s constant rotation. This meant a slip ring was needed to pass electricity into the spinning sphere. A piece of copper foil and a pair of improvised brushes served just fine. While [Pete]’s project, like its predecessor, doesn’t seem to have any recognized constellations drilled into the sphere, the foil slip ring opens up the possibility for a small microcontroller being fitted inside the globe with blinking lights.

Check out the video of [Pete]’s build in action after the break.
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altoids-pocket-projector

DIY Film Projector Fits In The Palm Of Your Hand

March 17, 2012 by 11 Comments

DSLRs aside, the price of digital cameras these days can make it easy to consider just tossing your old one out when it breaks. [Leonidas Tolias] had another idea, and with a few broken cameras he had on hand he constructed a slick little pocket-sized projector.

The project started out as a pair of lenses from busted cameras and an Altoids tin in which he mounted them. The larger lens from a video camera was installed on the exterior of the tin, while the smaller of the two was mounted inside. Bits from disposable cameras were used to create a set of film reels, which he supports with some hand cut scrap aluminum. He made some test photo slides by printing some images on transparency paper, which he can cycle through using a film advancement rig he built out of string and a couple of gears.

While you won’t be using this projector for your next boring PowerPoint presentation, it does work pretty well as you can see in pictures on [Leonidas’] site.

[Thanks, Taylor]

Projector Calibration On Uneven Surfaces Made Easy

February 29, 2012 by 18 Comments

projector-calibrator

If you are thinking of building your own flight/racing sim setup at home, you might want to check this out. [Alex] from the Garoa Hackerspace in Säo Paulo, Brazil put together a slick setup that makes projector image calibration a breeze.

When building a wraparound screen for such a simulator, you are likely to run into problems with both overlapping images and distortion from the curved projection. There are projectors that can easily adjust themselves to work in this sort of setup, but they are often very expensive, so [Alex] thought he would build a solution himself.

After studying a paper written by [Johnny Chung Lee] in 2004, he built a prototype display calibrator last year that used similar, though slightly tweaked methods to get the job done. This time around, [Alex] has improved his calibrator, making the process more precise and a bit quicker.

Light sensors and an Arduino are attached to the back of the projection medium, and a large broad scan of the screen is performed by the projector. His code then triggers an additional sweep of each corner to better estimate the exact edges of his projection surface. Since the video is tweaked in software rather than relying on the projector hardware to handle the task, the result is cheap and very accurate.

Don’t take our word for it though, check out [Alex’s] video demonstration below to see his calibrator in action.

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