Blumcaw Cupcake (Blinking, LED, Ultrasonic, Motorized, Cackling, Arduino, Witch) with 3d Printed Parts

Picture of Blumcaw Cupcake (Blinking, LED, Ultrasonic, Motorized, Cackling, Arduino, Witch) with 3d Printed Parts

This old witch has a blinking wart on her nose.  If you step too near (as determined by a Ping ultrasonic transducer), she will cackle out a greeting, her hat will spin and her eyes will flash seven colors.

Blumcaw can be made as a "plain old cupcake" without electronics and 3d printed parts if maintaining sanity is important in your household.
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Step 1:

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Let's start by making cupcakes!

Almond Cupcakes


Preheat the over to 350 degrees F and line a cupcake tin with 12 paper cups.



¾ cup softened butter

1 ¼ cup granulated sugar

3 eggs

½ teaspoon pure vanilla extract

½ teaspoon of almond extract

1 ½ cup all-purpose flour

½ teaspoon baking powder

½ cup milk


Put softened butter and granulated sugar into a mixing bowl and cream together with an electric mixer until light and fluffy. Add eggs, vanilla, and almond extract. Blend together. Add flour, baking powder, and milk. Mix until the batter is smooth. Fill a cookie scoop with batter and put batter into one cupcake paper. Repeat process until all of the paper cups are filled. Bake for 20 minutes or until the top of cupcake springs back when touched.

Yield: 12 cupcakes

Step 2:

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I needed a structure to hold the motor and route the wires--also I needed something to fit on the motor shaft and hold the witch's hat.  I made these parts with a MakerBot Replicator--design files here:

Step 3:

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Inside the L shaped tube there is a channel for wires.  At the top end of the L, there is a rectangular hole which holds the motor I am using.

Step 4:

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This is the schematic and parts list for the electronic components.

Step 5:

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Solder wires to the motor.
Awesome! You've got my vote!! :)
It's food with a crunch lol
It is very creative.
iceng2 years ago
Very cool  sweet... .:-)

Our toys are the best engineering.

Hahaha, love the flashing wart on her nose. Excellent!