Here’s a quick one from my wife. A salad table is an open frame with legs that has hardware cloth on the bottom of the frame to make shallow beds for growing greens. The table can be moved around so that it can be placed in the shade when it gets too hot for tender greens.
Here, read the artical on the NY Times, they’re better writers than me.
I was thinking it would be nice if instead of a large monolithic brick the LEGO Mindstorms control unit was more flexible and broken into functional modules. For instance the processor could be a reasonably sized brick with an Atmel or Pic chip and connectors for other modules. There could be an LCD module and one or more motor control modules and then of course a multitude of sensor modules. It seems like it should also be easier to use a variety of the off-the-shelf components to create sensor modules that trying to make them compatable to the RCX or NXT Controllers (but that may be an incorrect perseption based on my limited knowledge of those platforms).
I’m planning on doing some playing and prototyping with Lego Mindstorms. I was thinking it would be cool if there were a wider variety of sensors and motors available to build with. The idea is to build the components into bricks so that they could be used as easily as the standard components.
There is some precedent for this as you might expect.
There would undoubtedly be a varying level of complexity depending on what I was trying to accomplish, motors may need to be geared down to be usable and may need some additional circuitry to be compatible with the controller brick.
A couple ideas for components off the top of my head.
Motor brick based on cell phone vibrator motors.
Photo-resistor based light sensor
Really the possiblities are endless, but at some point time may be better spent on another project which will be my next April Maker Challenge entry.
I saw this article on the Make: blog last year, it didn’t have much detailed info at the time, but it stuck in my mind. They have now added a parts list and are supposed to be adding instructions at some point.
I thought it would be an interesting project, I think it only generates a sustained 60W and you obviously need a water supply (there will be a forthcoming AMC post on that topic). In theory you could run multiple generators in parallel, but that may be prohibitive compared to a larger more elaborate solution.
I am curious how the efficiency of this compares to a traditional water wheel.
One of the important tools in expiremental rocketry is the test stand. A test stand measures the thrust of a rocket over time. This information is important for validatation of your calculations, measuring the quality of your propellant and allowing you to change parameters to optimize the efficiency and characteristics of your motor.
A test stand is a relatively simple device, including the following:
Framework to safely secure the motor while it burns. Test stands can be oriented horizontally, vertically thrusting down or in special cases vertically thrusting up.
A load cell of some sort to measure thrust. This can be a stress guage load cell (either purchased or harvested from a digital scale), or a pressure transducer for a hydraulic system.
A circuit to amplify the output of the load cell.
Something to collect data. My plan is to use the arduino for data collection, although the sample rate is lower that a purpose built data collection device it should be adequete for my purposes.
I’ve had a passing interest in wind power (all forms lf alternative energy really) probably since reading about it in Mother Earth News as a lad. It’s something I’ve never really expored, but now with the potential of moving to the country in the next year or so I’ve started thinking about it again.
There are a couple companies that sell VAWTs targeted at the consumer but they tend to be very expensive with a very long ROI.
So I would like to try to build one myself, I had always had a traditional radial wind turbine in mind, but after a conversation with TCMaker Micheal I started looking into VAWTs. The build may be be pretty complex, but there are a number of reasons that make a VAWT prefereable to a radial turbine for the home user such as tolerance to high wind and lower maintenance.
This is something I’ve been researching for a while and started to work on last fall. The idea is to create solid rocket propellant for a reloadable rocket motor case. One of the local rocketeers turned a 54mm (one of the standard sizes) rocket motor case and forward closure out of aluminum stock. I also purchased a couple of feet of 2” graphite rod that will be turned into nozzles once I decide what size I need for my propellant.
Sugar propellant is pretty simple stuff consisting of around 30-40% sugar fuel and 60-70% potassium nitrate oxidizer. The difficult part is getting the two components fully incorporated and formed into chunks of propellant (called grains) without voids (bubbles).
There are a couple of techniques to do this. You can mix the two powders and then melt them somehow, or the method I chose which is to disolve the powders in water and then evaporate out the water so as to recrystalize the propellant (similar to making candy).
There many aspects of this project that make it challenging and there is much to learn, I’ve been taking my time.
Here are a couple of great web sites with lots of detailed information about sugar propellant and other aspects of rocketry.
Our kids and the neighbor kids all play in the alley and the driveways attached to the alley. Cars often drive much too fast and can be hard to see approaching because of the curve of the alley. So my idea is a system that uses multiple infrared beams or some other method to measure the speed of approaching cars. This could flash a light or LED sign reminding the drivers to slow down and give an audible alert for anyone standing in the alley. Sentries could be placed at either end of the section of the alley being used so as to guard against cars approaching from either direction.
My 11 month old son very recently became mobile and has proceeded to actively seek whatever trouble he can find. Just this morning he ended up playing in the dog water when he had been left in another room. So I’m thinking of a RFID based proximity tracking system. This would involve a Lilypad Arduino, RFID reader and some sort of sound generator that could be sewn into a padded pouch to be attached to the baby’s clothing. Then you could place RFID tags in any areas that you would prefer the baby stay away from. Once an RFID tag is detected an alert would sound. The sound could be customized based on the danger of a given area (e.g. dog water vs. basement stairs).
I picked up a toy drum pad at Goodwill a while ago with the hope of bending it, but either it’s unbendable or I don’t have the skill required (more likely). So instead I thought it would be a fun project to build an arduino driven drum sequencer. I found the contacts that trigger the different drum samples and the case is more than large enough for whatever circuitry and controls need to be added. Hopefully the pads will also still be usable while the sequence runs.
Today’s idea is a quickie. I’m not an organized person, but recently discovered the joys of pick bins to try to manage some of the entropy. Pick bins are stackable plastic containers with half open fronts so you can see and access the contents without unstacking.
We get milk delivered weekly in half gallon cartons by a milkman, so we go through a lot of cartons. So I had the idea to cut off the bottom of cartons and modify them to be stackable.
I was thinking of attaching dowels or wood strips to the bottoms, but my wife had the idea to attach flaps of milk carton around the bottom edge. Flanges FTW! I used staples to attach the flaps, although it’s a little fussy. I only have one carton available so far so can’t really demonstrate how they stack, but it seems like it should work great.
I’ve been fascinated by the Faraday generators such as those found in flashlights you shake to charge and the Kinetic Remote Control documented in Make. So I was thinking it would be cool if you could scale it down and create large pendants or other jewelry that contained a Faraday generator and one or more LEDs that would light up when shook or perhaps with just normal movement.
So I was thinking of using a drinking straw as the tube with the wire wrap. You could put pencil erasers on the ends to give the magnet a cushion. Small cylindrical rare earth magnets can be purchased from SuperMagnetMan.
It seems like the circuit should be relatively simple, a diode to control the current direction, as large of a capacitor as will fit to build up/smooth out the charge and a resistor to control current to the led(s). Surface mount or other small LEDs could be used to save on space.
The whole thing would be potted in epoxy or some other resin to make the shape of the pendant, etc.
I am a member of The Upper Midwest Experimental Rocketry Group (UMERG). Every fall UMERG travels to the Black Rock Desert in Nevada for an experimental rocket launch called BALLS. This year BALLS is having a keg loft which is a competition to successfully launch and recover a keg of beer. I cannot attend the launch this year but have volunteered to help out with the project.
I am building the nosecone for the keg loft rocket. The idea is to build a one-use nosecone out of two part expandable foam so that will cushion the impact of recovery for the keg which will be attached to the cone (and a substantial parachute of course).
I have though of various methods to accomplish this, but am partial to the most complex plan that will allow repeated production of nosecones. This plan involves a couple of steps.
1. Create a nosecone in the correct shape and profile using pink or blue foam insulation sheets stacked up and then shaped using a hot wire foam cutter and a template. Perhaps paint the original with epoxy and sand until very smooth.
2. Here’s the hardest (or at least most unknown) part. Once I have the nosecone I need to slather it up with mold release and start laying it up with fiberglass mat, building it up enough so that it will provide a strong mold. The most difficult part of that is that it may require vacuum bagging to do properly which is a whole other project.
3. Once I have a completed mold, it’s just a matter of applying mold release and pouring in the 2 part foam, and it should be easily repeatable for multiple launches.
Credit for the image goes to Team NUMB, that is their keg rocket from last year.
The Video Feedback Synthesizer uses input from optical sensors attached to the surface of a video screen (CRT) to drive a synthesizer. The synths can be simple 555 based circuits such as an optical theremin or Atari Punk Console or it could be a more complex synth. If simple circuits are used they would need to be mixed somehow for output.
The video image would be either generated by a microcontroller (i.e. arduino) or come from some other source such as a close circuit camera. The sensors are simple photo-resistors secured with suction cups or some other means.