CIRCUITPYTHON CIRCUIT PLAYGROUND / EXPRESS CRICKIT

Build the Owl

Fabrication

Minerva's eye movement is based on a very creative technique I first was shown by Phil Torrone in his B.O.B. robot seen here, made entirely of recycled cups and containers:

The basic principle is that there are two cups, one inside the other. The outer cup is the head/face and has cutouts for eye sockets -- through which the inner cup can be seen. The inner cup has pupils, irises, and eye whites on it.

When the inner cup is rotated, instant eye movment! Here's a demonstration using two clear cups:

Build the Head

The head and eyes will be made of two cups, one inside the other. The head will have eye holes cut from it, the inner cup will show through from the inside. Orient them “right side up”
mark and cut out the two eye sockets as shown. you can use a compass or trace something round for a consistent shape and size — or, just “eyeball” it! (sorry.)
Trim off any excess height if you want the head to be shorter — just do the same adjustment for the inner eye cup

Make the Eyes

To make the eyes, first trim the second cup's height down so it'll fit inside the head cup
Place a strip of white paper around inner cup, and tape it in place
Draw on pupils and irises or use stickers!

Micro Servo for Eye Movement

Mark the center point of the bottoms of both cups — this is where the micro servo and servo horn will go to connect through the cups
You can find center by measuring the diameter of the cup bottom, then halving that number and marking a point at that distance from the edge with a compass
Poke a small hole through the center of the inner eye cup, and a larger one through the outer head cup so the servo shaft will fit through
Mark the round collar of the servo on the cup to cut out the shape to hold the servo in place as shown
Glue the servo in place with a small bit of hot glue
Do the same to adhere the servo horn to the bottom of the eye cup — you can use a small screw to help with alignment

We'll connect the eye cup's servo horn to the head cup's servo shaft later, but first we'll build the owl's body.

Build the Body

You’ll use a smaller blue cup inverted for the body. It will hold the micro servo that turns the eyes, as well as hold the full size servo for the wings
Mark the micro servo’s four bottom screws with marker to make an impression on the “neck” of the body
Press the servo down with the head aligned in the center
Cut away the four edges formed by the marker points
Cut the blue body cup down to size if you like
Position the full servo on the back of the body so that there will be room for the micro servo "neck" above, as shown
Cut out the hole for the full servo, then press fit it in place
Feed in the servo cable first, and then press fit the servo in place as shown

Add Wings

Cut some material from a sacrificial light blue cup or other paper for the wings and other decoration
Draw out a wing pattern on one piece, then cut it out
Transfer the pattern to the underside of another piece of light blue cup material/paper to get the mirror image, then cut it out
Bend the “shoulders” in a little bit, then hot glue the wings to the body

Flapping Rig

We’ll flap the wings with a servo and some yarn. As the servo twists, the yarn that runs from each wing to the servo horn will rotate and cause the wings to flap back and forth
Widen the holes in two ends of your servo horn so you can thread the yarn through as shown
Fit the horn onto the servo
Hot glue one end of the yarn to a wing
Once the first spot cools, pull the yarn taught and then glue it to the second wing
Once all glue has cooled, you can trim the excess yarn beyond the attachment points, then tighten the yarn right a bit by twisting it over a servo arm
Test twisting the servo to see the wing flapping action!

Add Eyes

Add the eye cup to the head now by positioning the servo horn over the shaft
Gently press until the horn fits in place over the shaft -- you may need to wiggle the eye cup back and forth a bit to find the right spot!

Your robot is built, but now let's add some decoration!

Decoration

First, we'll add a beak. You can draw on a triangle, or use a sticker, then cut out a proper beak from the light blue cup or paper as shown below.

You can even draw on some eyebrows or use stickers.

A beak outline and a glued on beak add lots of character!

Don't forget about Minerva's stylish lightning bolt!

Popsicle Stick Legs

Carefully trim a couple of pieces from a popsicle stick for legs, then glue them on
Cut some short lengths of pipe cleaner, and fold and twist them in to adorable little owl feet! Glue them onto the popsicle sticks