Make: Online: Robotics Archives

Archive: Robotics

November 6, 2009

Online servo database with user reviews

A reader just sent me a link to servodatabase.com, which lists RC servo specifications and provides user reviews, a comparison engine, and various forms of sorting. Looks like a very good resource. [Thanks, Phil!]

Cupcake CNC build part 1: Introduction & background

Having just arrived home from a quick trip to the hardware store, I was pleasantly surprised to see a large, unmarked, cardboard box sitting on my front steps. This isn't an uncommon event, since I am constantly checking out cool products and projects for the Maker Shed, however this box was a bit larger than normal.

Oh wow, it's the Cupcake CNC kit from MakerBot Industries! I'd ordered it weeks earlier and had completely forgotten about it. (The truth is out: I have an atrocious memory, sad but true.)

And so the adventure begins! I'm going to document my "out of box experience" with a MakerBot. How many posts will the series be? I'm not sure since I've never built one. How often will I post about the build? Again, not sure, but I'll try to do at least one a week, maybe more, it all depends on how much free time I have between all my other maker-ly projects.

A little background: My CNC experiences

I've been tinkering with CNC for about 10 years, and consider myself an enthusiast, not an expert. I do own a few CNC mills, routers, and lathes. I have retrofitted old mills, and even build one from scratch. Pictured above is my mobile CNC machine, dubbed the "MobileC." I stuffed all the components into a mobile tool cart so I could bring it to hackerspaces, workshops, and events, all in the hopes of helping out fellow makers.

Read full story

November 4, 2009

Intern's Corner: Making Makey's "stretchy" body in Inventor

MAKE: Intern's Corner
Every other week, MAKE's awesome interns tell about the projects they're building in the Make: Labs, the trouble they've gotten into, and what they'll make next.

By Kris Magri, engineering intern

How I designed Makey, Part II: Creating the "stretchy" robot body in Inventor

When designing Makey the Robot for MAKE, Volume 19, I ran into a problem that plagues all kinds of designers -- how to continually redesign a body to accommodate changes in whatever's crammed inside it?

Once I'd sketched out Makey's configuration and modeled the major parts in Autodesk Inventor 3D modeling software, I really got into some of Inventor's awesome features. Inventor has three basic design types you work with: sketches, parts, and assemblies. Up to this point I had designed each individual component, including Makey's robot body, as a part, as shown in Figure A.

Fig. A: Makey's sheet metal body, near-final version, shown as a single part in Autodesk Inventor. Because I designed it as a component of an assembly, all the mounting holes and dropouts are perfectly aligned to internal robot components; if I move the components, Inventor automatically moves the holes.

Once I had these parts modeled, I placed them together into an assembly, as in Figure B. Then, I attempted to stretch the robot body as needed by making that part "Adaptive" inside the assembly. (That's what Inventor calls "stretchy" parts, and it's a powerful feature.)

Fig. B: Makey's body shown as part of an assembly in Inventor, constrained to the edges of the motors (at bottom, in blue). If I move the motors, the body automatically stretches to accommodate the new motor positions. Similarly, I constrained the battery boxes (at top, in tan) to the body, so wherever the body stretches, the battery boxes follow automatically. Nice!

Also, I cut holes into the body where I needed them for mounting the motors. This was the wrong approach! It seemed to work, but when I looked at the robot body as a part, outside of the assembly, the holes I had made weren't shown. They had simply vanished.

The reason for this is that Inventor can't know ahead of time how you're going to use a part. You could design one part that could be used in multiple assemblies, so if you alter the base part in any way inside one particular assembly, the alteration exists only in the assembly, but the base part is unchanged. Thus, my changes didn't "take hold."

The key was to create the robot body from inside the assembly. You can actually be inside an assembly and make a brand-new part. To do this, in the Assembly Panel area, instead of selecting Place Component, choose Create Component.

I ended up first creating what I called a "base plate," which existed solely to help me anchor all the parts, including the robot body. It would not be a part I would actually fabricate. I then placed the base plate, the motors, the Arduino, and the batteries into an assembly, using Place Component, and assembled it all by anchoring everything to the base plate (using constraints). This was pretty much what I had been doing before.

Now, still inside the assembly, I created a new part, via Create Component, which would become the robot body. I selected the material type Sheet Metal.ipt, since it's a sheet metal part, and created each bend and flange step by step, inside the assembly. This robot body now "belonged" to the assembly, and was adaptive inside the assembly. Any editing of it, from that point on, was always initiated from within the assembly.

Instead of making the body a specific width, I just made everything extra large with no dimensions. Once the body was formed, I finished editing, and now I was back inside the assembly with my new robot body. I then constrained the side of the body to an existing "edge" from another part, for instance, the sides of the motors (Figure B). When the constraint went into effect, the sides of the body "snapped" into place next to the motors. To make holes, I projected the motor mount holes onto the robot body, again edited the robot body part (from within the assembly), cut holes there, and then the holes "stayed put," so to speak.

Success at last -- I had modeled a fully adaptive robot body that I could easily modify to accommodate all the robot components I would be cramming inside it.

Next up: The battle to fit the brains inside.

More: How I designed Makey the robot, Part I: The first design

Frostruder MK2

Zach Hoeken wrote up a nice piece about the design of the MakerBot Frostruder MK2, currently in its second prototype. He talks about the challenges of designing a cheap, small device capable of computer-controlled cupcake frosting:

My first experiment was with some thick, chocolate frosting that you can find in nearly any grocery store. I simply wanted to see if it was possible to use air pressure to extrude frosting, so I wired up a solenoid to a switch and used that solenoid to turn the air pressure on and off to the syringe. I was using a 21GA (0.53mm) needle and a standard 60cc syringe. I hooked it up to the air pressure and opened the valve. Nothing happened right away, but I gradually turned the pressure up until about 50-60 PSI I started getting a frosting extrusion. I kept turning up the pressure to about 80 PSI where I got a really nice, very fast frosting extrusion that was about 0.5mm wide. Success!!!

From MAKE magazine:

In MAKE, Volume 19: Robots, Rovers, and Drones, learn how to make a model plane with an autopilot and a built-in robot brain. We'll also show you how to make a comfortable chair and footstool out of a single sheet of plywood, a bicyclist's vest that shows how fast you're going, and projects that introduce you to servomotors. All this, and lots more, in MAKE, Volume 19! Subscribe here, or buy the issue in the Maker Shed.

Giger: Custom humanoid robot

Giger is a really cool looking humanoid robot with impressive specs. The bot stands about 2 feet tall, weighs in around 11 lbs, has a WiFi camera, and runs embedded Linux. Did I mention it cost $10,000 to build! I guess all those actuators are expensive!

November 2, 2009

Auto-tracking sentry gun build

The beginnings of an Aliens-style (except, you know, without all the actual bullets and killing and so forth) automatic sentry gun from diederick. The tracking platform is obviously flexible, but I think he intends to mount an AirSoft gun. Build details and code downloads are available from his website.

October 31, 2009

Automatic sound-responsive puppet mouth

Guilherme Martins built this "talkie walkie" in response to a challenge to build a robot using only one servo. It responds to sound in real time, automatically controlling the movements of a lip-syncing paper mouth. [via Hack a Day]

October 30, 2009

Talking Arduino Halloween skeleton

Samuel Seide brings us this animatronic talking skull Instructable. It's motion-activated and uses a Waveshield kit for sound. [Thanks, Sam!]

More from Sam Seide:

In the Maker Shed:

Arduino WaveShield Kit

Make: Halloween Contest 2009

Microchip Technology Inc. and MAKE have teamed up to present to you the Make: Halloween Contest 2009! Show us your embedded microcontroller Halloween projects and you could be chosen as a winner.

October 29, 2009

iPhone Rock Band robot

The rhythm game arms race continues -- if they miniaturize the guitar games, we will miniaturize the guitar game robots!

My friend Joe Bowers writes:

Rock Band has been released on the iPhone, and even though its a lot of fun, I would rather have something play it for me. Preferably a robot! The light sensor sends data to an Arduino, which is waiting for a spike in the data. The Arduino runs the sensor data through some averaging filters, and sets a threshold for on and off. The iPhone touch screen isn't like most PDAs. It uses a capacitive touch screen. I had some conductive foam laying around, its usually used for shipping sensitive electronics. If I used something non conductive, like a plastic pen, the foam would do nothing to the screen. My solution to this was to put thin copper wires into the foam (I also used these wires to attach the foam to the servos)... Add all of the above together into a modified Pelican case, with a lot of hot glue (non glittery) and you have a robot that will gladly beat all your difficult songs, sit back and sip some fine tea.

OhBowz blog

Cockroach robot falls 28m, keeps running

The UC Berkeley Biomimetics Lab has created DASH (Dynamic Autonomous Sprawled Hexapod), a cockroach-inspired robot made from laser-cut cardboard laminated with some polymer. It runs fast and can withstand falls of 28 meters, after which it just keeps on about its business.

From MAKE magazine:

Muralizer prints art on the wall

Josh writes in to spread the word about the Muralizer verticle surface printer/plotter project - which is hopefully a kit in the making -

t's a drawbot that takes SVGs as input, letting you print vector graphics really big. The project was started at noisebridge, San Francisco's hackerspace, earlier this year, and we got a prototype going (a bit of video is up on the page).
I'd love to bring this piece of open hardware to the community as a kit, but need some help to do so. Inspired by the success of MakerBeam, I set up a kickstarter page. It would be great if people could pledge even a little bit to help make this tool available to artists (and those of us who want to be artists but are better at soldering than painting).

This could foreseeably give artist's assistants a run for their money (do they even get pay?) More on the project's planning and development can be found on Kickstarter & the Muralizer blog.

Related:

Hektor - The spray painting robot

October 28, 2009

Where are they now: Pleo the Dinosaur

He's baaaaacck! Pleo, the long-hyped, short-lived robotic baby dino is back on the market. Robert Oschler, of RobotsRule, has posted a piece, The Inside Story Behind Pleo's Rise, Fall, and Resurrection, that includes an interview with Derek Dotson, one of the founders of Ugobe, and now the CEO of Innvo Labs, the company that acquired the rights to Pleo.

RO: Are there plans for any new accessories or new Pleo models?

DD: I can talk about the 2010 Pleo model. That model will look the same as Pleo does now except it will have a new paint job and eye color to differentiate it from the current Pleos. Over the coming year we intend to give Pleo more depth to his personality and utilize the sensors better. For example, Pleo doesn't do a whole lot with the camera in his nose right now. It's not the hardware since the camera is a good quality camera. However there's a lot of room for improvement in the software. An example of a specific feature people want badly is getting Pleo to come to you. The 2010 model will do that. Also, Pleo uses power more efficiently which will lead to longer play times. To make Pleo more realistic, Pleo will develop certain character biases at birth so that everyone's Pleo will be different. As for the sensors, the reason why they are currently underutilized is due to a bottleneck in the serial bus that connects them to Pleo's processor resources. That's something we can fix without drastically altering Pleo's architecture. Once that happens, we can do more with them when it comes to Pleo's hearing, vision, etc. Beyond 2010 there will certainly be new creatures other than baby robot dinosaurs.

From MAKE magazine:
make volume 19 cover.gif
In MAKE, Volume 19: Robots, Rovers, and Drones, learn how to make a model plane with an autopilot and a built-in robot brain. We'll also show you how to make a comfortable chair and footstool out of a single sheet of plywood, a bicyclist's vest that shows how fast you're going, and projects that introduce you to servomotors. All this, and lots more, in MAKE, Volume 19! Subscribe here. Buy the issue in the Maker Shed.

Introducing the Creeper 2 - CANDY

WGhost9 writes -

Designed, built, and programmed in about record three weeks! It runs C on an Axon microcontroller. It uses all digital servos and can lift over twice its body weight. The software (soon to be given out open source) allows for six synchronous degrees of motion. Future additions will include foot sensors and a remote control option.

October 27, 2009

Mr. Wake, the uncatchable alarm clock robot

Here's another awesome project by Vadim Ryazanov of Let's Make Robots. Called Mr. Wake, this robot has the duty of protecting its alarm clock from any bleary-eyed, would-be assailants. Instead of running away after its snooze button has been pressed, like the Clocky, this 'bot engages a homebrew IR sensor as soon as the alarm goes off, and takes off if it detects anything even trying to get near the button.

I love the choice of building materials, especially the frame made of heat-formed plastic pens. Nice work!

October 26, 2009

PETMAN Prototype

The video you'll be seeing on every tech site shortly :)

Biped robot the balances dynamically using a human-like walking motion. It is a close relative to BigDog, sharing elements of the mechanical design and control.

How-To: Homemade pen plotter with laser attachment

Very thorough build notes from Viacheslav Slavinsky, who built a plotter from scratch, then souped it up by adding a 300 mW laser in place of the pen. I was interested to note that while 300 mW isn't a lot of laser power, apparently it can cut through slightly more than a centimeter of "high density foam." I'd be curious how it fares against EPS and/or XPS. [via Hack a Day]

Make robot parts with papier-mâché

What do you do if you don't have a vacuum former, and need to make a part for your robot body? Well, Vadim Ryazanov over at lets make robots has a simple solution: make them with papier-mâché! By using paper and a 1:1 mixture of wood glue and water, he was able to make a hemispherical shell for an upcoming project. Great idea!

How-To: Compressed air system for haunt props

Good tutorial on putting together a pneumatic power system for "home imagineering," as as the folks at Phantasmechanics call it. We've blogged their stuff a couple times before.

More:

Make: Halloween Contest 2009

Microchip Technology Inc. and MAKE have teamed up to present to you the Make: Halloween Contest 2009! Show us your embedded microcontroller Halloween projects and you could be chosen as a winner.

October 25, 2009

How-To: Giger Alien costume with motorized extensible tongue

From Creatrope. The mechanism of the tongue is made from Lego elements.

October 24, 2009

Incredibly creepy photoreactive animatronic, um, thing

From Let's Make Robots user lefthandsh8k, this truly disturbing light/shadow responsive haunt prop. It's controlled by a PIC16F84A and has seven servos and several vacuum-formed pops. The rest is "plywood, paper clips, and popsicle sticks." [Thanks, Matt!]

Make: Halloween Contest 2009

Microchip Technology Inc. and MAKE have teamed up to present to you the Make: Halloween Contest 2009! Show us your embedded microcontroller Halloween projects and you could be chosen as a winner.