We’ve been working on a fun new robot we call Metalbot. Our goal was to build an autonomous rover with a unibody design that was machined out of a single block of metal. We started with this 13” x 9” x 1.75” block of 6061 aluminum:
When the machining was done, the robot’s body looked like this. It’s a hollowed-out shell that is about 1/8” thick with holes, slots, and pockets for the motors, LEDs, sensors, and other electronics.
Once Metalbot was assembled with the internal components, it looked like this:
What do you think? We think it’s pretty cool looking. Do you like it?
In this first picture (which was taken through the polycarbonate enclosure), we clamped the part vertically in the vise and we’re using an 1/8″ end mill to machine the detail on the front of the nose. In a previous operation we clamped the stock flat and machined the top of the robot, so that work is already done. Because this part has features on every side, machining it required us to clamp the stock in the vise in 8 different orientations: top, left side, right side, back, front, 45-degree left nose, 45-degree right nose, and bottom.
In this next picture, we’re on the last setup, machining out the large pocket on the underside of the robot. This turned the aluminum block into a 1/8” thick shell. The large pocket appears to be glowing because the ring of LEDs we installed around the mill’s spindle are shining into the coolant that has filled the pocket. We’re using a 25mm (.98”) modular end mill here, which is designed to remove material fast. Of course, there were a lot of metal chips, but it’s important to remember that aluminum is easy and efficient to recycle.
In this picture we’re half way done digging the pocket and we have the machine take a break from the hard work to chamfer the outside contour:
Once the body is machined, we screwed in the wheels, motors, and electronics, which are screwed upside down on the underside, where they are easy to access when the robot is turned over. We will install a bottom plate later.
Then we did the wiring and soldering:
Here is the underside of the robot with most of the electronics installed. We’re using an Arduino Mega and a 4-channel Motor Controller, along with 4 Pololu gear motors to drive the mecanum wheels, which will allow the robot to strafe. The robot is also equipped with 6 Ping ultrasonic sensors for autonomous object detection, a LIPO battery, a main power switch, 6 NeoPixel RGB LEDs to indicate the state of each sensor, an Xbee Radio, and a panning servo (black thing in the middle). The robot will also be equipped with an MP3 module and speaker for sound, but those haven’t been installed yet.
The robot’s finished body is 8” wide and 12” long. The rover can be fitted with either the mecanum wheels shown or CNC-machined conventional wheels (not shown). Our original goal was just to machine a cool looking rover out of a single piece of metal, but as we went along, we decided to add some flexibility into the design for future enhancements in case we wanted to do more with it. The robot has been designed with a central spine of holes and ridges for attaching future add-ons, including a servo mounted in the center, which will support a pan-tilt turret for a camera, gun, or arm. We have designed the pan-tilt turret to utilize the Actobotics ecosystem, but other pan-tilt mechanisms could also be used. There are also holes on the front and rear of the top deck that are compatible with the full range of Actobotics components such as brackets, hubs, and channels, which really adds a lot of flexibility.
The next step is to work on the sensors and software programming. With its mecanum wheels, it should be able strafe like a champ very soon.
Here are a few more pictures of Metalbot so far. Let us know what you think. Do you like the overall design?
We would like to introduce you to our newest robot. Her name is Alumini, which is pronounced Ah-lu-min-ee. She’s a 12-legged running creature. She’s made out of custom, CNC-machined aluminum components designed to be like vertebrae and bones in keeping with the idea that is a creature not just a machine. Our goal was to create a little beastie without any visible wires or electronics (other than her sonar eyes). She does not have a box filled with electronics like our other robots. We wanted her to look like she was all legs. This meant we needed to use very small electronic parts and we had to do some very tricky wiring. The soldering on this project proved to be quite a challenge, but we were happy with the end results. Alumini is ten inches wide and consists of over 500 parts. Like her much larger 16-legged predecessor, Aluminalis, she uses gear motors to drive two crankshafts, one for each side. Alumini uses a tiny Arduino Pro Mini 328 microcontroller. She can operate via remote control (using an on-board xbee radio) or autonomously using her sonar eyes.
OUR POSTS ON THE CONSTRUCTION OF THIS ROBOT:
Alumini (Baby Aluminalis)
A Miniature Robot Control System
Here we are using our homemade CNC to machine a custom electronics plate for the new Mars Rover we’re building. The robot’s circuit boards and electronic components are mounted onto this plate, which is then mounted inside the robot’s main box. Check out the video and the photos below.
The completed electronics plate for the Mars Rover.
Here is the electronics plate with the various circuit boards and other electronic components mounted. Wiring and soldering comes next. The wires will go through the rectangular holes underneath each circuit board and then run beneath the plate.
Here at Beatty Robotics, we have a keen interest in mixing cool, old technology with exciting new technology. Recently, we became interested in Morse Code and telegraph equipment. We began exchanging written secret messages in Morse Code. And then we continued on by learning to tap the codes with rocks and listen to them at some distance. We are still learning and practicing, but it’s pretty clear that they are getting better and better and will soon be fluent. So now we’ve embarked on our next project, which is to build a functioning telegraph system by refurbishing several very old, antique telegraph keys and sounders, and then combining then with our modern electronics knowledge. We aren’t ready to show the completed project quite yet, but here are some pics of us wiring up the electronics. As we complete the project over the next few weeks, we’ll post pictures of the complete telegraph system (we’re hoping it’s going to look pretty cool), an explanation of how it all works, and the list of components.
Genevieve solders the headers on the Arduino Nano while I wire up the screw terminal board
I power up our wireless Xbee LCD screen to see if test messages are being transmitted properly from the Telegraph key. (The telegraph system itself won’t include an LCD screen. This was just for a test.)
Working together on some delicate soldering on the main microcontroller
See the finished product here: Wireless Telegraph
Today, we would like to introduce Terrabot, our Terrain Traveling Robot. Based on a modified “rock crawler” chassis, its primary purpose is to traverse rocks, branches, steep slopes, flower beds, boulders, mountain trails, and other extremely rough terrain.
Terrabot is equipped with 4-wheel steering (4WS). Two high torque servos shift machined aluminum linkages to rotate its front and back wheels independently. Note the navigation GPS on top of the back servo (on the left) and the sensor turret on the front (right). Terrabot’s four wheels are driven by two powerful brushless motors (bright blue) and robust gearboxes (centered in each axle).
Terrabot’s highly-articulated chassis is designed to twist up to 90 degrees as the robot is moving, allowing it to climb over huge boulders and other obstacles. In this picture, the chassis is articulated 45 degrees. Note that the back tires are still on the ground because the center linkages of the bot are twisted.
Terrabot’s topside electronics include a tiny Arduino Nano (lower left), an XBee Radio (right), and a 9-DOF Mongoose Inerntial Measurement Unit (IMU). The IMU measures the degree of tilt and the rate of acceleration in the X, Y, Z planes, which we plan to use for our stabilization algorithm.
Terrabot’s other electronics are stuffed into the little chamber inside the aluminum core (note the blue LED at the bottom of the picture). This includes the two Electronic Speed Controllers for the motors, the Pololu Maeastro motor/servo controller, the power rails, various voltage regulators, and other electronics. The navigation GPS (see the first picture), is mounted on top of the rear servo so that it has a clear view of the sky.
Terrabot Side View, showing the shocks, the frame, and LIPO battery beneath. Note the “roll posts” we installed on the top to protect the topside electronics if Terrabot falls off a rock during a climb and flips over. (We learned this one from experience!)
Terrabot Front View. There are three sonars mounted in the sensor turret, which rotates 270 degrees when the robot “looks around” to determine the best course through obstacle-ridden rough terrain.