While prepping for the upcoming apocalypse, the [prepforshtf] folks had time to design and build an automatic chicken feeder. It’s a very simple design (the best kind) that is made from standard PVC drain pipe. The pipe is positioned vertically and filled with chicken feed. A T-joint at the bottom of the pipe allows chickens to access the food inside. As food is eaten away, gravity pulls more food down to the feeding area.
That sounds pretty straight forward but it quickly became clear that checking the food level was a chore, almost as much as just feeding the chickens everyday. To remedy the requirement to constantly check the food level, the automatic feeder system was taken apart and modified to include a level indicator. Now, inside the 4-inch pipe resides a plate that resembles a butterfly valve.
This plate doesn’t control the flow of feed like a normal butterfly valve would, the feed actually holds the plate in a vertical position until the feed level drops below the plate. Since the plate has a heavier side, it will rotate when the feed no longer holds it in position. A large red pointer was attached to the plate’s axle and, since it is on the outside of the feeder, it allows a clear indication that the feeder needs a refill.
This is a great project that shows that even simple projects can be very beneficial in everyday life. With no electronics or batteries to fail, this feed indicator will certainly be very reliable. No doubt the chickens will be happy. Check this out for a more involved electricity-powered feeder.
Milling a PCB at home is a great way to save some time and money if you are making one-off circuit boards. There is a downside though, it’s a little tough. Sure, just export your Eagle design to CNC-Machine-understandable g-code and fire up your mill…. well, it’s not that easy.
The copper on a PCB blank can be anywhere from about 0.001 to 0.006 inches thick. When milling a board the ideal situation is to mill just deep enough to get through the copper but not cut too deep into the fiberglass backer board. Cutting too deep can weaken the board, break a bit, or in an extreme case, cut through the entire board.
Shallow cuts can result in another problem, inconsistent cut depth over the surface of the board. Check out the left photo above. The traces on the left side of the board appears to have just faded away. This happened because the circuit board was not flat. The side where the traces are missing from is lower than the other so the tool bit is not able to reach that part of the board. Since an ideal depth of cut is about 0.010 inches, even a very small amount of waviness or out of flatness can cause a serious problem in the milling process. If you have a hard time picturing what 0.010 inches is, think the thickness of two pieces of paper, it’s not a lot. There are two main contributors to the flatness problem; the PCB board and/or the machine’s bed. If the bed is not flat, the PCB won’t be. Even if the bed is flat, the PCB may be warped or bent.
PCB fabrication enthusiast [daedelus] had this exact problem, and in true hacker fashion, decided to do something about it. He created a software program called AutoLeveller that takes a g-code file and adds a probing section to the beginning before the milling operation. When the modified g-code file is run on the CNC Machine, it first probes the surface of the PCB in a grid pattern and maps the flatness variation of the PCB’s surface. Then, when running the program, it adjusts the height of the tool bit on the fly so that the actual depth of cut is consistent over the entire board, regardless of how flat or not it is. The result is a clean and usable PCB on the first try.
There is one catch: the Machine Control Software has to be set up to accept a probe. This is easy to do if communicating to the CNC Machine via a computers parallel port. An input pin on the parallel port is pulled high with a resistor and connected electrically to the PCB board. The tool spindle is grounded with a clip lead. When the tool touches the board, the input pin is pulled low and the Machine Control Software records the tool height for that specific XY position.
Continue reading “Mill Warped PCB Blanks On An Uneven Bed”
HaD reader [Greg] just finished an LCD picture frame project he’s been working on for a while. This is no ordinary photo display. His brother came up with the idea of having a device to display photos that could be changed remotely. [Greg] gave it some thought and came up with a plan; use a Raspi as the brains, connect to the internet via WiFi and display photos stored in a specific Google Drive folder. Any authorized user can upload photos remotely to the frame so the frame-owner has a constant stream of new photos to view.
Of course, using an off-the-shelf picture frame may have been too easy. Instead [Greg] decided to start with an old computer monitor and wrap it in a wooden frame so it looks good. Mounted to the back of the LCD is a Raspberry Pi with a USB WiFi dongle. The monitor runs at 14 VDC and luckily has an external power supply. Since the Pi runs at 5 V, a buck converter taps into the LCD’s input power and outputs a Pi-happy 5 volts.
This project doesn’t stop with displaying photos! The user can also switch to a weather view. The weather image displayed is generated from weather data pulled from the internet in the exact same manor used by folks who make stand-alone weather displays out of old Kindles. Oh yeah, switching between photos and weather is done by wireless remote! On the frame unit itself there is only one button, but it has 3 functions: A quick press turns the screen off, a short hold syncs with Google Drive and a long hold powers off the RaspPi.
If you’d like to make your own frame, [Greg] has graciously made all his scripts available for download…. not to mention his very detailed build log.
Water is a natural resource that some of use humans take for granted. It seems that we can turn on a facet to find an unlimited supply. That’s not true in all parts of the world. In the US, toilets use 27% of household water requirements. That’s a lot of water to only be used once. The water filling the toilet after the flush is the same as that comes out of the sink. [gregory] thought it would make sense to combine toilet tank filling with hand washing as those two activities happen at the same time.
To accomplish this, a DIY sink and faucet were put in-line with the toilet tank fill supply. The first step was to make a new tank lid. [gregory] used particle board and admits it probably isn’t the best material, but it is what he had on hand. A hole was cut in the lid where a metal bowl is glued in. Holes were drilled in the bottom of the bowl so that water could drain down into the tank. The faucet is just standard copper tubing. The curve was bent by hand using a wire wrap method to keep it from kinking. The only remaining part was to connect the fill line (after the fill valve) to the faucet. Now, when the toilet is flushed, the faucet starts flowing.
Continue reading “Saving The Planet One Flush At A Time”
The bicycle is a great invention. It is an extremely efficient method of transportation, even more so than walking. So why not harness that efficiency for other things? [Tony] had that same thought so he ordered a bike generator but after waiting too long for the company to send it, he decided to make his own.
[Tony] is an bicycle enthusiast so he had an old bike and an old training stand he could use for the project. Generating electricity from pedaling the bike requires some sort of generator. Lucky for him, [Tony] happened to have a cordless drill that stopped going in reverse. Since he had since upgraded, this was the perfect candidate for the generator. The drill was mounted to the training stand so that a pulley inserted in the chuck pressed against the rear wheel. Wires were added to connect the drill’s battery connectors to a 12vdc to 120vac inverter. As the bike is pedaled, the rear wheel spins the drill, which spins the drill motor creating DC voltage. That DC voltage is then converted to AC by the inverter. With a multimeter connected to the output from the drill, it is easy to adjust the pedaling speed to keep the output in the 11-14v range which is required by the inverter.
In the photo above, you can see a light bulb being powered by the bike. However, the bike powered generator could not power the larger load of a computer. The remedy for this was to purchase a solar charge controller and a 12 volt battery. The bike charges the battery and the battery can power the computer through the inverter.
Cruising around town on your electric bike is surely a good time…. unless your bike runs out of juice and you end up pedaling a heavy bike, battery, and motor back to your house. This unfortunate event happened to Troy just one too many times. The solution: to extend the range of his electric bike without making permanent modifications.
Troy admits his electric bike is on the lower side of the quality scale. On a good day he could get about 15 miles out of the bike before it required a recharge. He looked into getting more stock battery packs that he could charge and swap out mid-trip but the cost of these was prohibitive. To get the extra mileage, Troy decided on adding a couple of lead-acid batteries to the system.
The Curry-brand bike used a 24vdc battery. Troy happened to have two 12v batteries kicking around, which wired up in series would get him to his 24v goal. The new batteries are mounted on the bike’s cargo rack by way of some hardware store bracketry. The entire new ‘battery pack’ can be removed quickly by way of a few wing nuts.
Connecting the new batteries to the stock system go a little tricky and the stock battery pack did have to be modified slightly. The case was opened and leads were run from the positive and negative terminals to two new banana plugs mounted in the battery pack’s case. The leads from the new batteries plug right into the banana plugs on the stock battery pack. The new and old batteries are wired in parallel to keep the voltage at 24.
Troy found that he’s getting about twice the distance out of his new setup. Not to bad for a couple on-hand batteries and a few dollars in odds and ends.
3D Printing on Earth is soooo last year. Recently, NASA has sent a 3D Printer to the International Space Station in order to test printing capability in space. The agency’s ultimate goal is to have a means to make parts and tools for astronauts that are far away from earth.
So, why should NASA have all of the extra-terrestrial printing fun? Three 15 year-olds thought that same thing and decided to build their own space printer. It’s goal, however, is a bit different from the one on the ISS. This printer is made to print on other celestial bodies such as the moon or Mars, not in a space station. The students call their project the DELTA 3 and as its name implies, is a delta-style printer and that’s where all similarities with conventional printers end. This printer has tank tracks so that it can maneuver itself around the planet. There is no print bed. The printer prints directly to the surface of which it is resting on. The frame is open at the front of the printer so that it can back up leaving a free-standing print in its wake. It certainly beats the hot-glue versions seen before and we think this is the Automated Build Platform of the future, today!
The DELTA 3’s electronic controls are also quite different from the norm. There is a Lego EV3 controller that is responsible for navigating the printer around obstacles to find a suitable print area. Once a location has been picked out, the EV3 triggers the standard Arduino Mega/RAMPS combo to coordinate the printing.
The young creators brought their DELTA 3 to the World Robot Olympiad just last month. They came in 4th in their division.