Archive for the 'Make' Category

Ever since using my first Oscilloscope in the ’80s, I’ve wanted one. Though I’m a software person by trade, my hobbies have long included electronics in many forms. Heck, I’ll take a well tuned, clean, pinball game over a video game any day (and if it isn’t well tuned and clean, I’ll do that, too). An oscilloscope has long been the ultra-expensive super tool that my hobbyist pursuits just couldn’t justify the expense.

Not any more.

Recently, I picked up a cheap treadmill to turn into a “walking desk”. It works fine, save for the annoyance that it turns off ever 30 minutes and the control box is this big, ugly, clunky thing that clearly is a whole lot dumber than the LED display indicates. In adding some extra length to the control box’s cable, I noted there were only three wires; power, ground, and a signal wire.

Clearly, given price point and lack of real communication between control box and treadmill, the “protocol” between the two is likely nothing more than a PWM signal.

Which, given that the treadmill (Confidence Treadmill) is for my health, health is vital, and the best way to explore that signal deeper, I investigated picking up an oscilloscope for the first time in 15 years.

Boy howdy. What a difference those 15 years made! I was used to seeing depressing 4 digit numbers on scopes that were somewhat slow, very bulky and had little to no means of exporting data save for snapping a picture. Now? Less than $500 gets you a multi-input ‘scope capable of handling up to 100MHz signals with lots of analysis features and the ability to dump it all to USB or, in some cases, the network.

A bit of research revealed that the Rigol DS1102E is the most popular of the sort of entry level digital scopes.

However, the Owon scope pictured at left was only $50 more, has a much larger screen, and a LAN port. Rigol’s ds2072 is similar, but nearly $400 more and is backordered pretty much everywhere. While the Owon has had some negative reviews, the latest version seems to have addressed almost all of the criticisms. That, combined with the realization that I’m not exactly going to be pushing it (and a bit of a desire for immediate gratification) and I went with the Owon.

Couldn’t be happier. The Owon SDS7102 seems to work just fine; more than enough for my needs. The user interface is pretty mediocre, but passable.

I’ll let people far more competent than me properly review the scope.

Read the rest of this entry »

Since picking up an Ultimaker nearly a year ago, I’ve printed many things (and wrote a very well received article for Make: Ultimate Guide to 3D Printing).

These are many of them and some lessons learned from each.

Koch Snowflake Tree Ornament Baubles

This is Thingiverse Object #35561.

Every year, we have an annual ornament exchange in our neighborhood. Last year, I used EMSL’s Egg-Bot to create an Eichler themed ornament.

This year, I started down the path of custom designing an ornament for printing, but grabbed the Koch snowflake baubles from Thingiverse.

Lesson Learned: Design software is hard to use. 3D design software is harder. You’d think a simple circle with some stars and words extruded in 3-space would be easy to do. Still, people totally dig the unique texture and shapes of these. In hindsight, I probably should have used Inkscape (awful, but works and is what is used for the egg-bot) to do a 2D design and then extrude that.

Read the rest of this entry »

For the Teensy Blaster, I used a Teensy v2.0 board from PJRC. It is a tiny board containing a not-so-limited AVR chip (32K of flash, >2K RAM, 1K of EEPROM, and a slew of I/O pins) and a mini-USB port with the ability to be USB bus powered. Tiny. Versatile. And cheap at $16/board! $24 nearly gets you nearly 4x the memory and nearly doubles the I/O ports.

Today, I ran across Teensy v3.0 on Kickstarter. In pretty much the same sized package, the Teensy v3.0 features a 32bit ARM Cortex-M4 board with 128K of Flash(!!), 16K of RAM(!!), 2K of EEPROM, and a slew of I/O options. If that weren’t enough, it includes support for IR, a high quality audio interface, an optional real time clock, 4 DMA channels, and support for touch sensor inputs. And more. Much more. Holy cow! Truly, a nutty amount of computing power in a 1.4″ x 0.7″ package!

And it can be used from both Arduino and C.

So, yeah, funded. No brainer.

Then, at the thank you for funding this project page, there is a thing you might be interested link that leads to the Digispark.

Wait. What? A board barely bigger than a USB connector that features an Arduino compatible CPU with multiple I/O pins, 8K of flash, PWM on 3 pins, ADC on 4 pins and many many different shields?!

For $8-$10 / board?!

Sign me up! (And I did!)

In my “spare” time (hah!), I hack on Arduino a bit. Mostly because there are tons and tons of 3rd party libraries that make hacking up a hardware solution mostly a bit of soldering followed by gluing together some pre-made software bits. The Arduino IDE is Java based and… well… not terribly awesome (to be fair — it isn’t awful, just quite lacking beyond the basics).

With the release of Mountain Lion, most Arduino installations were broken. Fortunately, this can be fixed by grabbing the latest bits from here and there.

If all went well, you should see the device show up in /dev/ as something like /dev/tty.usbmodem12341.

After a while with the Ultimaker, a series of notes on the various things one can do to tune the 3D printing experience.

Some of this is specific to the Ultimaker, but most of it is not. Much of this is personal preference and, frankly, there is probably some stuff in here that is wildly sub-optimal. But, hey, it has worked for me and it worked better than it did when I started.

I.e. feedback and corrections are quite welcome!

First, a note on consumables. I have stuck with PLA (polylactic acid) exclusively. It is a plant derived material that requires a lower temperature and is quite thoroughly non-toxic (there are lots of articles about fume-venting ABS… not so with PLA). As well, when I screw up — which is often — the resulting garbage is biodegradable (however, I’m donating my “pile of PLA” to someone who needs input into a PLA scrap-to-usable-filament project).

PLA also doesn’t require — though it can benefit from — a heated print bed. ABS, the other common material, seemingly really does (though one can live without).

Thus, these tips are optimized to PLA.

These tips are also somewhat ordered in the steps that they should be done to maximize benefit. In some cases, that is because the earlier steps have a bigger ROI than later ones. In others, it is simply that the later steps really require the earlier steps first. Read the rest of this entry »

Evolution of a Design

When I started this, as can be seen in the image at left, the case was two parts that fit together in a semi-complex manner (Actually, the very first version just had a little plastic square that covered the AVR, but nothing else). It was hard to print with any quality and, frankly, the front looked awful. So I simplified it such that the IR LED could stick out a small hole, as seen in the middle. But then it dawned on my that the translucent plastics might just be transparent enough to IR that no hole was needed at all.

And sure enough, it just worked!

Thus, the design is now even simpler (assuming you have translucent filament).

Both professionally and as a couch surfer, I’ve found myself interacting with a great deal of devices that can be controlled via infrared remotes. Often, remotes lost in the depths of a couch or misplaced in the fridge (it happens). Clearly, I needed an IR blaster that could be controlled from a computer to both eliminate the “losing the remote” problem and to integrate control of multiple devices into a single UI. Conveniently, Arduino micro-controllers with integrated USB ports are commonly available and quite cheap. Adding an IR LED to an Arduino is trivial, as the ever popular TV-B-Gone project demonstrates.

Thus, the Teensy IR Blaster was born. I started with the Teensy v2.0 AVR-based micro controller that includes USB support. It unofficially supports Arduino using the Teensyduino extension. To this, I added Ken Shirriff’s IRremote library modified fro the Teensyduino environment and Read the rest of this entry »

This is a short video of the printing of an Octopus I’ve been using as a test model. The Ultimaker is printing at 250% of normal speed. I started at 100% for the first layers until a solid base was created and then cranked the speed to 250%. It could go faster, I think.

At that speed, the quality of the print suffers a bit. I believe, is mostly due to slop in my belts. I need to print some belt tensioners which will take up the slack nicely.

The print quality is both better than the out of the box experience and tons faster.

This is the result of a combination of upgrades:

• Upgraded the Ultimaker’s firmware to the latest beta version. It has all kinds of features that enable both higher quality and higher speed prints.
• Upgraded to using Pronterface to send the G-Code to the printer. It allows for communication at 250kbaud and doesn’t periodically pause like Replicator-G does if you forget and leave the temperature monitor panel open.
• Moved to using SkeinForge-48 as the slicer.

All three of these tasks were a downright pain to do. All three have been written up in another post.

For now, enjoy some 3D printer music….

Some build notes from my Ultimaker build experience…..

Overall, it took me roughly 4 days to build the Ultimaker. The first two days were a couple of long stretches and the last two were much shorter. Tuning the device to yield usable prints has taken a bit more time, too, and I still have a long ways to go.

At left is a print made using the default firmware with relatively default settings in ReplicatorG. Stringy as heck, but otherwise quite good! Software and hardware tuning are reserved for another article.

This is some random build notes from the build and roughly correspond in order to the assembly instructions themselves.

By and large, assembly was relatively straightforward. The only real disaster I had was with the cooling fan used on the extruder. When I tried to mount it, it shattered — literally disintegrated into dozens of pieces — in my hand.

The Ultimaker arrives in a surprisingly small, heavy, box. No surprise; wood is heavy and the Ultimaker is largely a wooden box with some very crafty electronics built into it. Frankly, the laser-cut wood based construction is, in and of itself, a bit of a hobbyist kit revolution. Wood is cheap and very strong, yielding kits that can be quite precise, extremely durable, and still remain accessibly affordable.

Random notes below the fold…

Read the rest of this entry »

Throughout the anticipation of the delivery of the Ultimaker (4 to 6 weeks — as are pretty much all 3D printers these days!) and the week of assembly (another post), I spent a bunch of time researching software and otherwise attempting to grok the toolchain without a tool to apply the chain to.

In short, 3D printing requires a slew of tools and the tools are… ugh… unrefined, if not downright user abusive. Not that this comes as a surprise. Affordable 3D printing is a very new market and it’ll take a few years for the science to be nailed down enough that an easy UI can be wrapped around it.

And it is moving rapidly. Thus, if you are reading this anywhere after about 3 to 6 months from now, it is likely that the landscape has changed.

As well, this is a decidedly Mac OS X centric / Ultimaker centric view of the world. I’ll likely update again in a month or so after I’ve set up the Printrbot.

To drive a 3D printer, there are quite a few stages of software that are employed. In the maker world, there are generally multiple answers to any given stage in the overall chain. If you are working with a commercial printer, it is likely that the stages closest to the printer — the driver, assuredly, maybe more — are fixed. Read the rest of this entry »

While I’m looking to the Ultimaker (see my previous post for thoughts on the Ultimaker) (now received– time to start assembly!) as my primary go-to, general purpose, home manufacturing device, I was both interested in a second printer as a platform for experimentation and as a secondary printer for when I need to turn out a bunch of stuff.

Because I wasn’t going to be afraid to modify it, I wanted something pretty cheap. The RepRap platform seems pretty interesting, but it also seems semi-fragile (and feedback on various sites indicates that it is harder to keep aligned than others, though I don’t know how true that really is).

Along came the Printrbot Kickstarter project. I ended up funding that at the $424 level. I’ll use the Ultimaker to print all the plastic parts. The Printrbot is really pretty extraordinary. It is an elegantly simple design, has decent precision and, through its simplicity, is extremely customizable.

Also, the Printrbot story and the whole Kickstarter concept is pretty cool and this seemed like a perfect opportunity to jump in and fund something.