Sometimes, it is interesting to see what you can build from the bits that you have in your junk drawer. [Dr West] decided to build a printer with spare parts including a hard drive, a scanner base and an Arduino. The result is a rather cool printer that prints out the image using a pencil, tapping the image out one dot at a time. The software converts the image into an array, with 0 representing white and 1 representing black. The printer itself works a bit like an old-school CRT TV: the scanner array moves the printer along a horizontal line, then moves it vertically and along another horizontal line. It then triggers the hard drive actuator to create a mark on the paper if there is a 1 in the array at that point.
We’ve seen a few drawing printers before, but most use a plotter or CNC approach, where the motors move the pencil on an X-Y . This type of dot matrix printer (sometimes called a dotter) isn’t as efficient, but it’s a lot of fun and shows what can be achieved with a few bits of junk and a some ingenuity.
Continue reading “Junk Build Printer Uses Pencil To Print”
Christmas has come and gone, and no doubt garbage cans are filling with toys that got but a single use before giving up the ghost. If you scrounge around, you might get lucky and score a busted RC car so you can be like [Mike] and build a completely unnecessary nitro-powered pencil sharpener.
This is one from the [Tim The Tool Man Taylor] “more power” files. To be fair, [Mike] acknowledges as much right up front, and as a learning tool for these super-powerful internal combustion engines, we think it’s a pretty cool project. After dealing with a seized cylinder on what looks to be a VX .18 engine rated at about 1.1 horsepower, [Mike] learns the basics of starting and controlling the engine. Once coupled to a pencil sharpener that clearly isn’t engineered to work at a bazillion RPM and jury-rigging a damper for the clutch, [Mike] fires up the engine and races through a pack of 10 pencils in record time.
As silly as this hack seems, it could come in handy if you decide to go into the colored pencil jewelry market at production levels.
Continue reading “Garbage can RC car Engine Powers Ridiculous Pencil Sharpener”
Everyone’s favorite machinist, tinkerer, YouTube celebrity, deadpan comedian, and Canadian is back with a tale of popping a few benzos, stumbling around Mexico, and wondering why everyone else on the planet is so stupid.
The hero of our story considered the feasibility of one hundred and eighty-sixth trimester abortions as he stood outside a Mexican airport watching a stockbroker complain about the battery in his cellphone. Meanwhile, cars drove by.
Here’s how you charge a phone with a car battery and an ‘ol Dixon Ticonderoga.
To charge a battery, all you really need to do is connect the terminals to a power source with the right voltage. A cell phone battery needs about three volts, and a car battery has twelve. You need a voltage divider. You can get that with a pencil. Take out a knife, get to the carbon and clay wrapped in wood, and wire the battery up. Make a cut a quarter of the way down this rather long resistor, and there you will find something around three volts.
Does it work? Yeah. It works even better if you have some tape to hold wires onto the cell phone battery when charging. Is it smart? It is if there is no other conceivable way of charging your cell phone. Should you do it? Nah. Video below. Thanks [Morris] for the link.
Continue reading “MacGyver, Jedi Knights, Ammo Stockpiles, and Candy Crush”
[Peter] proved he has equal parts prowess, patience, and perseverance with this colored pencil ring (imgur link). The ring is made from a cross-section of several colored pencils. The idea seems simple. The build process IS simple. As always though, the devil is in the details.
[Peter] started with a cheap pack of colored pencils. They have to be hexagonal pencils, as round ones won’t work well for this build. [Peter] used two nails to align the pencils, and medium thickness Cyanoacrylate glue to bond them together. Cyanoacrylate (aka super glue) is a very strong but inflexible bond. We’re curious if a different adhesive might have worked better for this task.
Once the block of glued pencils was dry, [Peter] drilled a hole approximately his ring size. He used a band saw to cut a rough ring blank around the hole, then headed to the wood lathe. He mounted the ring with a jam chuck, which is a piece of wood turned to an interference fit with the workpiece. The problem was that the jam chuck cracked the ring as it was being installed. [Peter] was able to glue the ring back together, and turn it down on his lathe.
Click past the break for more on [Peter’s] ring.
Continue reading “A Ring of Colored Pencils”
The gang over at Waterloo Labs decided to add a team-building aspect to a plain old Etch a Sketch. Instead of just twisting the two knobs with your own mitts, they’re converting this giant pencil’s movements into Etch a Sketch art.
The challenge here is figuring out a reliable way to track the tip of the pencil as it moves through the air. You may have already guess that they are using a Microsoft Kinect depth camera for this task. The Windows SDK for the device actually has a wrapper that helps it to play nicely with LabView, where the data is converted to position commands for the display.
On the Etch a Sketch side of things they’ve chosen the time-tested technique of adding gears and stepper motors to each of the toy’s knobs. As you can see from the video after the break, the results are mixed. We’d say from the CNC ‘W’ demo that is shown there’s room for improvement when it comes to the motor driver. We can’t really tell if the Kinect data translation is working as intended or not. But we say load it up and bring to a conference. We’re sure it’ll attract a lot of attention just like this giant version did.
Continue reading “Giant pencil used as an Etch a Sketch stylus”
[Onefivefour] was surprised that his E-flite Blade MCX radio controlled helicopter came with a charger that used AA batteries to recharge the lithium batteries in the flying unit. Yeah, that’s a bit crazy. He set out to modify the base unit to work with AC power. There are four batteries inside this base unit, one of them powers the charge detector circuit and the others are used to juice-up the chopper’s rechargeable cells. He took a 5V regulated charger from a Motorola cellphone and modified it to interface with the contacts for the three AA cells. Like the Magic Trackpad hack, he did this without altering the holder by cutting a couple of pencils to length and attaching the positive and negative contacts from the AC charger to them. Check out the video after the break for a walk though, noting how he still has the option to go back to battery power if he so chooses.
Continue reading “Toy helicopter charging fix”
Who wouldn’t want to install this little bot as your newest pencil holder? Place a pencil tip-down and it will keep it from falling using two motors. There is a Dynamic Vision Sensor for each axis that provides feedback, but it’s not the same as using a camera. These sensors pick up changes in pixel contrast, outputting a positive or negative number based on the direction the pencil is beginning to fall. An NXP2103 running at 64 MHz reads in the values and drives the pair of servo motors accordingly.
If you’re interested in the nitty-gritty the full paper is available from the page linked above. It goes into great detail about the algorithm used, and includes plots and histograms showing the data capture during a balancing session. Or you can skip the eggheaded exercises and watch the video after the break.
Continue reading “Pencil balancer a bit noisy for desk use”