Materials and tools used:
- 1/4", 1/8", and 1/16" plexiglass
- Trotec Laser Engraver
- Sugru (http://www.sugru.com/)
- acrylic plexiglass bonding glue
- plexiglass polish
- heat gun
- many different electronic components, including a Hokuyo UHG laser, Sharp IR distance sensors, MicroStrain IMU, Microsoft Kinect, Logitech webcam, fitPC-2, Phidget interface board, Minibox power supply, cooling fan, tri-color LEDs, and more
- Adobe Illustrator
The steps in this Instructable are as follows:
1-5: Designing the plexiglass planes
6: Cutting and prototyping with cardboard
7: Embedding nuts and losing weight
8: Adding color with crayons
9: Putting it all together
Step 1: Mounting the Augmentation Mounting Planes
The inside of the stocks are dremeled to fit the 1/4" T-shaped mounting bars. This augmentation uses three bars: top, bottom, and middle. They each contained holes for screws to attach to the middle mounting plane (detailed in the next step).
Step 2: Measuring and Laying Out Components
Draw each component in Illustrator and begin to lay them out within the form factor of allowed space between the stocks. (from last step: 104mm wide, 600mm tall, and 87mm deep) Keep in mind which components need to be near each other, make sure they do not overlap (in the attached image in looks like some overlap, but some components are on the front of the plane and others are on the back), and make sure to account for extruding attachments such as USB connectors and other wires.
The VGo modifications are done in three planes: front (t-shirt), middle, and back. The attached drawing is just for the middle plane.
Step 3: Adding External Visual Appeal
The shirt was designed with a back, middle, and top. The 1/4" middle has the flower shapes cut out, where 2 layers of 1/8" etched flowers are inserted with LEDs. The 1/8" back and 1/16" top are used to hold the LED wires and to hold the flowers in place.
The back of the back plane was also designed with the same etched flower pattern from the t-shirt.
Step 4: Adding Three-dimensional Mounts (sensor Array and IMU)
The sensor array was designed with top and bottom horizontal planes that contain holes for vertical planes to lock in place. The entire array mount connects to the back plane via a set of teeth from the horizontal planes, and the back plane connects to an internal mounting wall with a set of screws and nuts.
Another three-dimensional component was the MicroStain IMU, which must be mounted parallel to the ground. It sits on a horizontal plane with teeth that lock into the vertical middle and back planes.
Step 5: Adding Three-dimensional Mounts (kinect + Webcam and Base Laser)
The laser won't fit inside of the base, so the top panel of the base had to be dremeled to fit the shape of the laser, as it extrudes out of the top of the base. The mount for the laser also contains a Sharp IR sensor that is placed in the front of the base. It props the laser up by utilizing screw holes that already exist in the base and some interlocking horizontal and vertical planes. The top of the laser is orange, but by adding a layer of white Sugru over it it matches the sleek color scheme and look of the VGo robot.
The kinect + webcam had to fit into the form factor of the width of the robot, as you don't want to compromise the aesthetic look by adding something that is wider than the robot. The Kinect was made less wide by detaching it's longest circuit board (the board was then placed into the middle planes) and dremeling any parts of the metal case that exceeded the size of its other board. The webcam needed to look down towards the base of the robot so its mount is an angled box that locks into the webcam mount.
Step 6: Cutting and Prototyping With Cardboard
The laser cutter used was a Trotec Laser Engraver which interfaces with Corel Draw. To make my design plans cuttable I exported the drawings in Illustrator as Illustrator 8 EPS files. Cut lines are changed to red 0.004 thick lines, and etch shapes are changed to black fills.
The images in this step are of early prototypes, while the designs in previous steps were final designs, so they may not correspond.
Step 7: Embedding Hex Nuts and Losing Weight
To hold all three layers together, clamp them and use acrylic bonding glue along the edges (it will sink into the rest of the surface area between layers). Acrylic bonding glue is also used to hold together any interlocking horizontal to vertical joints.
In any case a robot's motors controlling its movement are only so powerful, so we have to lose as much weight as possible. To do so perforation holes were added to the 1/4" planes, about 132 per square inch, losing roughly 45% of the weight.
Step 8: Adding Color With Crayons
Step 9: Putting It All Together
To stand the Kinect and webcam up on top of the robot, 3D printed stocks were made (not by me, so their design is not covered in this Instructable) that sit inside of the VGo stocks. They are placed on stands inside of the stocks, through a dremeled hole in the top of the stocks. A 3D printed top was also placed on top of the Kinect case. Plexiglass rings were added over the dremeled holes in the VGo stocks and the dremeled hole in the base for the laser. To hold them in place and make the holes look clean and sleek, Sugru was added under and around the rings.
That's it! All done. 9 months of work condensed to an Instructable (whoa!). This work could not have been done without the University of Massachusetts Lowell, the UMass Lowell Robotics Lab, Holly Yanco, and Kate Tsui, whose dissertation was the driving force behind augmenting this robot.