In true Nerd Club fashion, no sooner have we decided to start (or re-start) a project, and something else comes along and takes our attention away. This time, it was the postie bringing us a clutch of four floppy disk drives, won off eBay just 48 hours earlier.
Why would anyone want such old crappy hardware?
Well, for a start the winning bid was just 1p, so even allowing �3 for delivery, they came to less than a pound each. (if you're ever at a car boot, and someone is selling off job-lots of drives as they often do, for 50p or so, it's worth grabbing a few). But that's not the main reason - we actually went out looking for old floppies, as a source of cheap stepper motors.
Here's what we found in one of our floppy drives:
The bit we're interested in is the stepper motor - usually seen at the back, next to the IDE cable connector. Whip the lid off and take a look. The motor usually has a corkscrew shaft and a bit of grease on it. These aren't important right now.
Normally two screws is all it takes to get the motor out of the casing. The other end of the shaft is usually in a part moulded into the actual casing. If the shaft and casing are all one unit (as often found in low voltage or portable/laptop drives) you'll need to undo a few more screws. But 99% of drives are built like this one.
Undo the two screws and pull the stepper motor backwards. Eventually it will stop. That's the flexible ribbon cable holding it in place. Pull until it comes free.
If your motor still has the ribbon cable attached, you can use this to connect to a PCB in future. But most messing about with steppers is first done on a breadboard/prototyping board, in which case simply solder some wires onto each of the four connection points.
The rest of the drive can be junked. We've got what we came for. But if you're in a scavenging mood, there's plenty more to be had from these little things. Get rid of the disk caddy and moving parts...
Remove the plate above the spinning head and pull. The actual spinning head should come off in your hands. It's a doughnut-shaped magnet with a spindle in the middle. It should just lift off. Undo a few screws from the bit it's sitting on and you should see some cool coils.
It's these coils that control how the head spins. As each coil is activated in a particular sequence, it can attract or repel the magnets inside the spinny head thing. If you really wanted to, you could use this as another crude stepper motor. But it's probably more hassle than it's worth. The coils themselves, however, might be useful in other projects.
Let's take a quick look at what we've scavenged from our floppy disk drive:
In our drive (though not all) we found some useful 0.1" pitch flexible ribbon cables. These are useful for joining two or more PCBs together, especially if soldering isn't your strong point - they're quite easy to work with.
There were a few springs, used to pull the disk drawer in and out, and a few "peg-style" clip springs too.
The rod that the disk head was on could always come in useful for something robot-y.
Of course, the stepper motor is going to come in handy - that's what we came for in the first place! And there were also a few "self-tapping" screws which might be handy in future. They have a slightly wider thread than normal screws and are perfect for fixing into plastic or acrylic (where they make their own thread as they are screwed into place, hence the name)
Not a bad haul for a few minutes work.
Get yourself some component bins, a few cheap drives and get to work!
Friday, September 30, 2011
Back to business - little guitars again
It's been a disruptive couple of weeks - the move from Brighton to North Wales was ok, but finding everything in the aftermath has proved a nightmare! So what better way to find out what's here, what's missing, and what's still somewhere in the depths of our monster Transit Van than to actually get making stuff.
Not having access to the tools (nor even the internet for most of the last few weeks) means quite a bit of software development has been going on. We've been working quite a bit of late on
Setting up HackLlan - a new "hackspace" in the mountains
Creating a time-line-driven sequencer for players to create and share music over the 'web
But now we've got some of our stuff out of boxes and into the hack-cupboard, it's time to get making again.
Not having access to the tools (nor even the internet for most of the last few weeks) means quite a bit of software development has been going on. We've been working quite a bit of late on
Setting up HackLlan - a new "hackspace" in the mountains
Creating a time-line-driven sequencer for players to create and share music over the 'web
But now we've got some of our stuff out of boxes and into the hack-cupboard, it's time to get making again.
a state of chaos in the new cupboard-come-office
if you can't find it, look in one of those stacking boxes...
We're actually quite excited about how well the software development is coming along, even though it's not much more than an array of samples and a piano-roll style screen. Our current guitar prototype works quite well with the software, but we're still having a few teething problems. Whether this is the software, the hardware or the firmware, we've yet to resolve. So in true "hacker" style, we've attacked all three at once.
Here's the new pcb layout, etched and ready to solder.
Before we left Brighton we were working on using a solder pot to connect the tiny fine-pitch multi-core wires to the circuit boards. We've got everything ready to go - except the components box with all our SMT stuff isn't immediately to hand. That doesn't mean it's not here. But it could just as easily mean it's somewhere in the back of a van, under a heap of household items and bedding....
New micro jumping robot is as big as an ant
When I have written posts on jumping robots, they are usually as big as an eraser or iPod. However, this robot is smaller, and its basically the size of an small bug. The bot is actually like a bug, because it stores up potential energy and then releases it to jump into the air. It works by having rubber springs that are connected to a little leg and the other side of the rubber bands are connected to the body (see photo above). When the bands are pressed inward, the energy is being stored, and then when it gets released the robot jumps into midair. Sounds pretty cool, even though its basically the size of a insect. Thanks for reading and check out the video below to see this bot in action!