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William Waters III - N7IPY


The basic collar construction is made up of 108 molded ¼ x ¼ Plexiglas square rods glued to a top and bottom set of Plexiglas disks.  Held within the collar is a center support, black mask, the radar rotation motor and other parts.

Building the collar is a fun project, but as with all parts of the B9 takes time and effort to do right.  My wife found a $40 toaster oven for me to use at one of the big-box stores and I barrowed the bending jig from a club member, shipping it home when I was done bending the ribs.


It took me a few evenings of measuring before I committed to cutting the ¼ clear Plexiglas into disks, 4 in all, all different diameters.  At my day job there is a nice vertical mill in the prototype shop that I have access to so I went there on a Saturday and using an end mill cut the 4 round plates.  Once I had all the measurements marked I then cut the center holes and removed extra material to reduce the weight of the collar.


I decided to attach the Radar Base with Lazy Susan to the Collar top using 5 metal pins that are attached to the Plexiglas that matches the lazy Susan mounting holes.  Again I used the vertical mill to get exact holes drilled in the plastic.


Gluing the 108 Ribs in place is not hard but it is time consuming.  I found that I needed to clamp each rib in place to get a good fit which meant I could only glue 8 Ribs a day.  I used the thicker #16 Weldon Solvent Glue which takes a little longer to harden. Behind the ribs is a black mask made from 3 layers of glued black construction paper, that was then painted matt black.  I mounted 4 PIR Motion sensors behind the Ribs, 90 degrees apart.  They will be used to wake the robot up when someone comes in range.  I plan to also use these sensors to do the initial people sensing when it is autonomous mode. It took a week to get the ribbs glued in place, doing 8 at a time and allowing for glue drying time. 
Now that it is done and mated to the Radar Section with elecronics bay and controllers in place I am fairly happy with it. 

Small Toaster Oven used to heat the plastic parts before bending in the jig.
Cutting out execss plastic to help reduce the overall weight of the Collar structure.
124 Cut and molded ribbs ready for assembly.
The Center Support is a 2.5 inch plexy tube with a cut out to allow the radar rotation motor to fit.
Test fir of top plexy plate with mounting studs and stepper motor.
Test fit of the top and bottom plates with center support along witht the stepper motor and a few ri
Rib Gluing Process
Rib gluing where you can see the PIR Sensor
1 of 4 PIR Motion Sensors
Click for large view
Top View of Collar showing Sensors and Motor
One Side of the Electronics Bay showing 1 of 2 Controllers
Click for large view
The B9 Project So Far on a Test Stand

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(C) 2007 - 2018  William Waters   Last Updated February 2018