Building the B9 Robot Radar Section
I finally started my radar. I was waiting because I needed to get some 1/8 inch thick acrylic. While cleaning up the shop, I found some that I had stashed away. It seems that last year when I purchased some 1/4 inch thick acrylic, it arrived damaged. When they sent a sheet to replace the damaged one, they threw in some 1/8 inch acrylic, so I had it all along. Here I am cutting out a 2 inch center hole in one of the rings.
This is the setup I used to cut the slots in the 5 larger rings. I took a 1/4 inch aluminum channel and cut a notch in the back to the correct depth. It allowed the 5 large rings to slide in and expose only the plastic I needed to cut out. It also gave me slots that were exactly 1/4 inch. I used a Dremel tool with cut-off wheel to cut the slots.
Here's the stack of 10 rings (5 small & 5 large). I set some 1/4 inch square acrylic rods in the slots to see how everything lined up. So far so good. The white plastic in the center is a 1 1/2 inch PVC pipe HUB. It has a 2 inch diameter.
I constructed the lower portion of the radar from two acrylic circles. I routed a step in each of the circles and I plan on cutting a strip from styrene plastic to wrap around the edge. I glued two 1/2 inch thick curved acrylic bars on each side to support the radar "ears". The lower circle has the lazy susan mounted to it. Here I placed the neck bellows on the PVC center pipe to check the fit.
I changed out the lazy susan under the radar. I had one of the cheap 9 inch ones from the local home center and they are quite noisy and not real smooth. I ordered a 9 in version of the same type I used for the torso. It works much better and allows me to used a motor on the inside rim to make it rotate..
Finally got back to building the radar section. Here are two pictures showing the slot that I cut into the bubble support arm. There is a guide attached to the radar that rides in the slot. The guide serves several purposes. First it allows the bubble support arm to raise and lower and keeps the bubble facing in the correct direction. It also allows the entire bubble/brain assembly to move in the same direction as the radar
This picture shows that the guide can pivot up out of the slot. This allows the whole bubble support arm and bubble/brain assembly to be removed for service or disassembly when I am moving the robot. I wanted to spring load a locking pin, but a screw just seems much easier. Maybe someday.
I took apart my radar last weekend and painted it the same silver as the torso. It has only been the gray primer color since Halloween. I just love the hard shiny finish automotive enamel paint give when used with the hardener. You can't get that kind of finish from a spray can.
I debated on texturing or not. Since I wanted the paint done for the Wonderfest show, I figured I'd not put on the texture and could always repaint it later if I decided to go with the textured finish.
I received my motors in the mail today for the radar. These motors will turn the two sensors (spinners) on the "ears". I spent all evening mounting them on the underside of the radar and wiring them up. At about 11 PM I was able to power them on and they look great.
Here's a short video showing my radar spinners in action. You can hear the motors turning, but you will also hear the sound of water running in the background. Our basement sink is about 10 feet away and I didn't realize I had captured that sound on the video until now.