Codebender Shuts Down was a cloud based IDE for Arduino development. It was made for hackers by a few fellows in Greece. Unfortunately, while they saw some serious success, they were never able to convert it all the way into a viable business.

By November 31st will be completely shut down. They assure users that the site will be in read-only mode for as long as the end of the year, but longer if the traffic justifies it. Codebender made it all the way to 10,000 monthly active users, but hosting and administration overshadowed this success to the tune of 25,000 dollars a month. Not so much as far as businesses go, but without revenue it’s more than enough to shut down a site. Their business plan aimed to tailor their services for specific chip manufacturers and other companies but those deals never came together.

It’s a pity, we were excited to see if Codebender could continue to grow. They were certainly doing some really interesting stuff like remote code upload. As the comments on the site show, many users, especially educators and Chromebook users, loved Codebender — your code isn’t stuck on one computer and where there was a browser there was an IDE.

Two paid services will remain (starting at $10/month) at addresses with different TLDs. But the post does mention that the Codebender project started as Open Source. Their GitHub repo isn’t a clear path for rolling your own, but if you do manage to hack together a working Codebender implementation we’d love to hear about it.

Hook Any Mouse to an Acorn

Acorn was one of the great IT giants that rose high and then fell to obscurity during the rise of personal computing. However, for many hobbyists these computers are as important and as loved as the Commodore 64. [Simon Inns] has made a great adapter to interface modern USB mice to these old boxes. 

After thirty years of interaction with people, one might be hard pressed to find a working mouse for an older computer. On top of that, even if you did, these mice are likely a lackluster experience to begin with. They were made long before industrial designers were invited to play with computers and are often frustrating and weird. Cotton swabs and alcohol are involved, to say the least.

[Simon]’s box converts a regular USB HID compliant mouse to a quadrature signal that these 8-bit computers like. The computer then counts the fake pulses and happily moves the cursor around. No stranger to useful conversion boxes, he used an Atmel micro (AT90USB1287) with a good set of USB peripherals. It’s all nicely packed into a project box. There’s a switch on the front to select between emulation modes.

If you’d like one for yourself the code and schematics are available on his site. As you can see in the video below, the device works well!

Continue reading “Hook Any Mouse to an Acorn”

A Machine Shop in A Toolbox: Just Add Time

You don’t need any fancy tools. A CNC machine is nice. A 3D printer can help. Laser cutters are just great. However, when it comes to actually making something, none of this is exactly necessary. With a basic set of hand tools and a few simple power tools, most of which can be picked up for a pittance, many things of surprising complexity, precision, and quality can be made.

Not as pretty, but worked just the same.
Not as pretty, but worked just the same.

A while back I was working on a ring light for my 3D printer. I already had a collection of LEDs, as all hackers are weak for a five-dollar assortment box. So I got on my CAD software of choice and modeled out a ring that I was going to laser cut out of plywood. It would have holes for each of the LEDs. To get a file ready for laser cutting ook around ten minutes. I started to get ready to leave the house and do the ten minute drive to the hackerspace, the ten minutes firing up and using the laser cutter (assuming it wasn’t occupied) and the drive back. It suddenly occurred to me that I was being very silly. I pulled out a sheet of plywood. Drew three circles on it with a compass and subdivided the circle. Under ten minutes of work with basic layout tools, a power drill, and a coping saw and I had the part. This was versus the 40 minutes it would have taken me to fire up the laser cutter.

A lot of the tools we use today were made to win against economies of scale. However, we’re often not doing any of that. We’re building one or two. Often the sheer set-up cost isn’t worth it. Likewise, the skill from being able to do it without the machine will come in handy. There’s an art to using a file properly and getting the expected result. So it’s good to take the time now to practice and develop the manual skills, you never know when you’ll be out trying to do an emergency fit on a part and no one in the area has a single milling machine just sitting around.

So what tools would a hacker need to get the closest to a machine shop without having one or spending too much money? For most needs a person can build a surprising amount of things with nothing more than the following tools.

Basic Metrology: Now if you really want to do precision work you may need more expensive tools, but often we are just spoiled by precision. We can design our parts with a little more wiggle room and just spend the time adjusting them.

  • Calipers – Since they are so cheap now, there is no reason not to own a simple digital or dial caliper. For most work this will be able to measure most things well enough for all practical purposes. Honestly if you’re building something that needs a full metrology suite you’re probably making it hard on yourself. This even goes for production work.
  • Rule – Not a ruler. A steel rule. This will have a ground flat edge and precise graduations. You can use this for layout.

    Chris over at Clickspring is always using the glued paper trick to do some very accurate work.
    Chris over at Clickspring is always using the glued paper trick to do some very accurate work.
  • Square – A carpenter’s combination square can be used for a lot of layout. It’s not as fantastically precise as a real machinists square, but I’ve yet to ever actually need the precision of a real machinist’s square for every day hacking.
  • Compass & Protractor – To be able to layout circles and angles is key. Buy a robust one rather than a nice one. The kind for school children is pretty good.
  • Scribe and Punch- Pencil and Permanent Marker- In lieu of layout fluid a permanent marker is enough to bring out scribed lines on metal. A pencil is great for the rest of the materials. Lastly a punch is essential for drilling holes.
  • Glue stick – With CAD software as amazing and free as it is there’s no reason not to just print out a template and glue it to your part. Contact cement or a simple glue stick is all you need

Working: Next comes working the material itself. Hand working typically happens in two steps. Bulk removal and fine removal. To do the first you need good layout and a bit of experience. To do the second you need even better layout, a godlike amount of patience, a strong back (or a workbench at the right height) and a way to hold the part firmly.

Trust me when I say I've worn out a lot of work gloves and these hold up the longest.
Trust me when I say I’ve worn out a lot of work gloves and these hold up the longest.
  • Stubby Knife (and cut proof gloves) – A knife that lets you get your fingers close to the work, such as an exacto blade or a utility knife. That being said I’m lucky to still have digits with full working ranges. It doesn’t matter how careful you are, it is statistically impossible to not eventually cut yourself with a knife. It then comes down to how damaging that cut will be. Most will hit the flesh of the hand and be relatively harmless, just painful. However, if you hit a tendon say goodbye to full range of motion forever and hello to surgery and picking up an instrument (source: Grew up with an occupational therapist as a parent, that’ll scare the gloves on ya). To that end I highly recommend a good set of kevlar cut-proof gloves. My absolute favorite is the Ansell Blue Nitrile Coated Kevlar HyFlex glove. They’re pricey but they last forever (I would go through five sets of leather gloves in the time it took me to start to see wear on the HyFlex) and give practically normal range of motion and feel for the work.
  • Big File – A coarse bastard file is a must have. If you can only afford one get one with a flat side and a round side. It will be a little difficult not to cut into right angles, but a bit of masking tape or a section of plastic can help with this. Also, the traditional brands like Nicholson can no longer be trusted, do some research before paying more than five bucks for a regular file these days. Only a few brands deliver a long-lasting file. Lastly, watch a few videos on the proper use of a file. If you do it right they’ll cut fast and last a long time.
  • Round File – A round file is useful for a staggering amount of things, but mostly for fitting holes and shaping radii.
  • Little Files – I recommend spending a bit on a nice quality set. One small round, small triangle, and small-D shaped file is a good start. I’d also recommend a small flat file with a safe side for sharpening corners.
  • Japanese Pull Saw – Wood is a great prototyping material and there is no better saw for general woodworking than a Japanese pull saw. If you want to get deeper into the craft then there is a reason for the other saws, but general joints, shaping, etc can be done quickly and precisely with the saw.
  • Hacksaw – A hacksaw can cut through any material as long as you buy the right blade and are willing to sweat. A good hacksaw frame can put a lot of tension on a blade without a lot of added bulk. If it has both a lever action and a thumb screw it is likely to be able to do this. A good hacksaw blade is almost never sold with the frame.

    The metal fabricator's handbook will blow your mind if you've ever wondered how people made armor or hot-rods. It's hard, but technically simple.
    The metal fabricator’s handbook will blow your mind if you’ve ever wondered how people made armor or hot-rods. It’s hard, but technically simple.
  • Coping Saw – Think of a coping saw as a manual laser cutter. There are some nice ones out there, but the blade is the important thing to buy. Weirdly they are getting harder to find these days. I think less people are using them but no shop should be without a coping saw.
  • Plier Set – A set of pliers. Needle Nose, End Cutters, Side Cutters, and Lineman’s is a good place to start.
  • Tongs – I define a tong as any plier that you’re going to heat up. Keep this one separate from your regular pliers. It’s also good for holding something while you beat on it with a hammer. You’ll probably break it eventually.
  • Clamp or Vise – No shop should be without some way of holding a piece firmly. This is one of your most important tools. Really high quality ones usually show up at garage sales or Craigslist; sold by ignorant family members. Look for one that has nice thick jaws and a flat area on the back.
  • Hammer and Scrap Wood – You’d be amazed at the shapes a person can draw out of regular sheet stock with a hammer and scrap wood. This is a must have for the shop. A regular claw hammer and a ball peen are an absolute necessity.

Modern Day Luxuries: There’s no need to stay completely manual though. With Horrible Freight right around the corner or slightly better alternatives for a premium at the home improvement shop there’s no need to to have a few modern luxuries.

A pencil torch and vise come together for a brazing operation.
A pencil torch and vise come together for a brazing operation.
  • Dremel – A cheap rotary tool will make quick work of a lot of shaping tasks. Definitely saves time and there are some things that can’t be done economically without one. Also good for feeding an endless stream of cutting disks into to cut sheet stock without deforming it. Saves time on polishing too if you want to get fancy. Have to be careful not to waste too much time setting-up and forcing this tool to do the work. It’s often considerably underpowered compared to some sweat and hand files.
  • Power Drill and Bits – There is absolutely no reason not to have a decent power drill these days. Get a corded one if you can’t swing the money for a nicer model cordless. This will drill holes, sand, and occasionally act as a shitty lathe. Especially handy if you just want to bring something round into a tolerance for some sort of fit. Get a decent set of drill bits unless you hate yourself. I bought a 30 dollar set with decent coatings and have been replacing the individual bits with their higher quality counterparts as I burn through them. I’m currently on my third 1/8th inch bit.

    Let's be honest. The hobby of 3D printing doesn't really save any time.
    Let’s be honest. The hobby of 3D printing doesn’t really save any time.
  • Pencil Torch – Lastly a good quality torch or pencil torch does wonders. I burned through a few cheaper torches before I finally dropped a hundred dollars on a good quality Portasol. With a torch one can heat treat metals, solder, braze, and more. A person can cut plastics, weld plastics, and shrink heat shrink. It’s an essential tool.

For the rest I wouldn’t go nuts. I’d file them under, “buy as you need”. Of course there are things like screwdrivers etc. but this was intended for shaping operations, not general repair. I would recommend buying, not a tap and die set exactly, but picking a size of fastener (in my case, M3, M6, and M8) and buying the tap, die, and drill set for those.

In the end most prototyping, even today, ends up with a hacker having to still do some 19th century work to get it to fit. However, if you’ve ever seen a real watchmaker at work, you’ll know just how ridiculously far you can get on knowledge of metal backed up by skill with a file.

I know there are a lot of you out there with more and similar experience than I have with this sort of thing. At what point do you resort to modern tools? Any tasks that you found went faster the old-fashioned way? Any tools that I missed? Hand work isn’t a fading skill by any measure, but it’s easy to forget about it with 3D printers as cheap as they are. However, for any technical person it adds instant worth and a far deeper understanding of design and fabrication if you can do it by hand.

Are Today’s Engineers Worse?

Today’s engineers are just as good as the ones that came before, but that should not be the case and there is massive room for improvement. Improvement that can be realized by looking for the best of the world to come and the one we left behind.

Hey kids! Let's learn why the CE certifications exist!
Hey kids! Let’s learn why the CE certifications exist!

Survivorship bias is real. When we look at the accomplishments of the engineers that came before us we are forced to only look at the best examples. It first really occurred to me that this was real when I saw what I still consider to be the most atrocious piece of consumer oriented engineering the world has yet seen: the Campbell’s soup warmer.

This soup warmer is a poor combination of aluminum and Bakelite forged into the lowest tier of value engineering during its age. Yet it comes from the same time that put us on the moon: we still remember and celebrate Apollo. It’s possible that the soup warmer is forgotten because those who owned it perished from home fires, electrocution, or a diet of Campbell’s soup, but it’s likely that it just wasn’t worth remembering. It was bad engineering.

In fact, there’s mountains of objects. Coffee pots whose handles fell off. Switches that burned or shocked us. Cars that were ugly and barely worked. Literal mountains of pure refuse that never should have seen the light of day. Now we are here.

The world of engineering has changed. My girlfriend and I once snuck into an old factory in Louisville, Kentucky. The place was a foundry and the only building that survived the fire that ended the business. It happened to be where they stored their professional correspondence and sand casting patterns. It was moldy, dangerous, and a little frightening but I saw something amazing when we cracked open one of the file cabinets. It was folders and folders of all the communication that went into a single product. It was an old enough factory that some of it was before the widespread adoption of telephony and all documents had to be mailed from place to place.

Continue reading “Are Today’s Engineers Worse?”

Make Any PC A Thousand Dollar Gaming Rig With Cloud Gaming

The best gaming platform is a cloud server with a $4,000 dollar graphics card you can rent when you need it.

[Larry] has  done this sort of thing before with Amazon’s EC2, but recently Microsoft has been offering a beta access to some of NVIDIA’s Tesla M60 graphics cards. As long as you have a fairly beefy connection that can support 30 Mbps of streaming data, you can play just about any imaginable game at 60fps on the ultimate settings.

It takes a bit of configuration magic and quite a few different utilities to get it all going, but in the end [Larry] is able to play Overwatch on max settings at a nice 60fps for $1.56 an hour. Considering that just buying the graphics card alone will set you back 2500 hours of play time, for the casual gamer, this is a great deal.

It’s interesting to see computers start to become a rentable resource. People have been attempting streaming computers for a while now, but this one is seriously impressive. With such a powerful graphics card you could use this for anything intensive, need a super high-powered video editing station for a day or two? A CAD station to make anyone jealous? Just pay a few dollars of cloud time and get to it!

The Little Things I Didn’t Know About Small DC Motors

We’ve all taken apart a small toy and pulled out one of those little can motors. “With this! I can do anything!” we proclaim as we hold it aloft. Ten minutes later, after we’ve made it spin a few times, it goes into the drawer never to be seen again.

It’s all their fault

It always seems like they are in everything but getting them to function usefully in a project is a fool’s errand. What the heck are they for? Where do people learn the black magic needed to make them function? It’s easy enough to pull out the specification sheet for them. Most of them are made by or are made to imitate motors from the Mabuchi Motor Corporation of Japan. That company alone is responsible for over 1.5 billion tiny motors a year.

More than Just the Specs

In the specs, you’ll find things like running speed, voltage, stall current, and stall torque. But they offer anything but a convincing application guide, or a basic set of assumptions an engineer should make before using one. This is by no means a complete list, and a skip over the electrics nearly completely as that aspect of DC motors in unreasonably well documented.

The paint mixers high running speed and infrequent use make it a decent candidate for hooking directly to the motor.
The paint mixers high running speed and infrequent use make it a decent candidate for hooking directly to the motor.

The first thing to note is that they really aren’t meant to drive anything directly. They are meant to be isolated from the actual driving by a gear train. This is for a lot of reasons. The first is that they typically spin very fast, 6,000 – 15,000 rpm is not atypical for even the tiniest motor. So even though the datasheet may throw out something impressive like it being a 3 watt motor, it’s not exactly true. Rather, it’s 3 N*m/s per 15,000 rotations per minute motor. Or a mere 1.2 milliwatt per rotation, which is an odd sort of unit that I’m just using for demonstration, but it gives you the feeling that there’s not a ton of “oomph” available. However, if you start to combine lots of rotations together using a gear train, you can start to get some real power out of it, even with the friction losses.

The only consumer items I can think of that regularly break this rule are very cheap children’s toys, which aren’t designed to last long anyway, and those powered erasers and coffee stirrers. Both of these are taking for granted that their torque needs are low and their speed needs are high, or that the motor burning out is no real loss for the world (at least in the short term).

This is because the motors derate nearly instantly. Most of these motors are hundreds of loops of very thin enameled wire wrapped around some silicon steel plates spot welded or otherwise coerced together. This means that even a small heat event of a few milliseconds could be enough to burn through the 10 micrometer thick coating insulating the coils from each other. Practically speaking, if you stall a little motor a few times in a row you might as well throw it away, because there’s no guessing what its actual performance rating is anymore. Likewise, consistently difficult start-ups, over voltage, over current, and other abuse can quickly ruin the motor. Because the energy it produces is meant to spread over lots of rotations, the motor is simply not designed (nor could it be reasonably built) to produce it all in one dramatic push.

Making Contact

Pololu has the clearest picture of the different kind of brushes inside these small motors.
Pololu has the clearest picture of the different kind of brushes inside these small motors.

This brings me to another small note about these tiny motors. Most of them don’t have the carbon brushes one begins to expect from the more powerful motors. Mostly they have a strip of copper that’s been stamped to have a few fingers pressing against the commutator. There’s lots of pros to these metal contacts and it’s not all cost cutting, but unless you have managed to read “Electrical Contacts” by Ragnar Holm and actually understood it, they’re hard to explain. There’s all sorts of magic. For example, just forming the right kind of oxide film on the surface of the commutator is a battle all on its own.

It’s a weird trade off. You can make the motor cheaper with the metal contacts, for one. Metal contacts also have much lower friction than carbon or graphite brushes. They’re quieter, and they also transfer less current, which may seem like a bad thing, but if you have a stalled motor with hairlike strands transferring the pixies around the last thing you’d want to do is transfer as much current as possible through them. However, a paper thin sheet of copper is not going to last very long either.

So it comes down to this, at least as I understand it: if bursts of very fast, low energy, high efficiency motion is all that’s required of the motor over its operational life then the metal strip brushes are perfect. If you need to run the motor for a long stretches at a time and noise isn’t an issue then the carbon brush version will work, just don’t stall it. It will cost a little bit more.

Take Care of Your Tiny Motors

Here is one of these can motors being restrained properly. Only torque on the case itself is restrained. The motor is otherwise free to move.
Here is one of these motors being restrained properly. Only torque on the case is restrained. The motor is otherwise free to move.

To touch one other small mechanical consideration. They are not designed to take any axial load at all, or really even any radial load either. Most of them have a plastic or aluminum bronze bushing, press-fit into a simple stamped steel body. So if you design a gearbox for one of these be sure to put as little force as possible on the bearing surfaces. If you’ve ever taken apart a small toy you’ve likely noticed that the motor can slide back and forth a bit in its mounting. This is why.

Lastly, because most of these motors are just not intended to run anywhere near their written maximum specifications it is best to assume that their specifications are a well intentioned but complete lie. Most designs work with the bottom 25% of the max number written on the spreadsheet. Running the motor anywhere near the top is usually guaranteed to brick it over time.

These are useful and ubiquitous motors, but unlike their more powerful cousins they have their own set of challenges to work with. However, considering you can buy them by the pound for cheaper than candy, there’s a good reason to get familiar with them.

Teardown a Classic : Tektronix P6042 Current Probe

[Paul Rako]’s teardown of his treasured P6042 current probe shows why Tektronix commands so much respect among the old hats of the electronics world.

Built in 1969, the P6042 is pretty sparse transistor-wise when compared a modern sensor. The user would clip the current probe, permanently attached to the case since the circuit was tuned for each one, over a wire and view the change in volts on an oscilloscope. When the voltage division on the oscilloscope was set properly the current in a circuit could be easily seen.

The teardown is of a working unit so it’s not completely disassembled, but it also sits as a nice guide on refurbishing your own P6043, if you manage to snag one from somewhere. Aside from capacitors and oxidized switch contacts there’s not much that can go wrong with this one.

As for how it compares, the linear power supply, analog circuit design, and general excellent engineering has the P6042 coming in with a cleaner signal than some newer models. Not bad for a relic! Do any of you have a favorite old bit of measurement kit?