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.
Now I've added the vanes and the center ring. The
ring was cut from a PVC Sewer pipe from Home Depot.
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.
Here I have primed the radar
unit. Next I will need to texture it and then apply the top coats.
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.
