Lesson | Flinger-Drummer | Micro:Bit

Overview

This build works out to be useful in two ways; flinging stuff and drumming on stuff. The overall concept is to increase the inertia of the moving servo by quickly snapping the cable tie to flick the arm. The mechanics of this build is modeled after a foot pedal used in a drum kit.

The flinging aspect is just fun. Fling coins, buttons and ping-pong balls. When using the animation recording feature of the Animate Shield, beats can be recorded an looped including adjusting the speed.

Skills + Goals

Construction

Build the project following assembly instructions

Music

Animate a beat

Carpentry

Basic carpentry principals and hardware

Coding

Learn about using delays in code to control movement timing

Age 10+

Time 60 min

Materials

A 1 x Screwdriver
B 1 x Servo Sock
C 1 x Arm
D 1 x Pulley Disc (Large)
E 1 x Pulley Disc (small)
F 1 x Stick
G 2 x Wood Blocks
H 1 x Cable Tie
I 1 x Angle Bracket
J 14 x #6 x 1/2" Screws
K 2 x #6 x 1" Screws
L 2 x Washers
M1 x Wood Base

Build Steps

Step 1

For this build, we will work from a front long edge in terms of reference for things being mounted This can be either side when starting.

First, mount Servo Sock [A] on the left side of the base [C]. Make sure that the disc [B] facing the front is the one powered by the servo motor. Use 4 of the #6x1/2" screws to mount the Servo Sock centred on the base and in 17mm from the end.

Step 2

Mount a wood block [A] on the right side of the base [B] 16mm from the right side of the board, the important part is the block is not centred on the board but, should be flush with the front face of the Servo Sock. Use 2 of the #6 x 1/2" screws to mount the block.

Step 3

Mount bracket [A] to the wood block using 2 of the #6 x 1/2" screws. The front face of the bracket should be flush with the woodblock and front face of the Servo Sock [C]. The distance from the right side of the base [B] should be 38mm.

Step 4

Pass the cable tie [A] through the end to make a loop that will fit a screw through the hole.

Discs [B] and [C] will mont together to create the pulley/ The slot in the smaller disc [C] will fit the folded end of the cable tie which will be held in place by the #6 x 1/2" screw.

Step 5

Mark a line up from the bottom of the side edge of the wood block [C] at 17mm and then in the centre of the block, this is where the screw will go into the block for the pivot point.

Then using a #6 x 1" screw [A] and 2 of the washers [B] mount the pulley to the wood block using the top hole in the angle bracket.

Step 6

Use a #6 x 1" screw [A] to connect the pulley to the wood block. This will make them rotate together.

Step 7

Attached the wood stick to the Servo Sock disc using 2 of the #6 x 1/2" screws [B]. Then mount the loop in the table tie to the top hole in the stick using another #6 x 1/2" screw [A]

Step 8

Mount the flinger arm [A] to the centre of the wood block using 2 screws [B]

Step 9

*if* planning to use the build for flinging, the bottom row of holes can be used to add a bump stop. The #6 x 1/2" screw [A] only needs to be driven in about halfway so that it hits the bracket.

Step 10

Connect the Servo motor to connection 13 on the animate breakout board. Connect the power to your USB power supply/battery using the USB to DC cable.

If using the Animate Breakout Code
-The arm can be moved using the first knob labeled P0.
-Click the "A" button to record, a 'hit' and loop it back using the record/play buttons. You can also use this method to record a launch sequence animation.

Step 11

Note - If you would like to change the angle of the arm , the 5 holes [A] along the top of the large pulley disc can be used. Simply take out the #6 x 1" screw and change to another position.

The Code

This example uses the "A" button to move the arm into a launch position. The "B" button launches

Code Breakdown

On start we move to the middle position
When the “A” button is pressed we move the servo to the load position
When the “B” button is pressed we launch
Note – You may need to change the servo position numbers or reverse them based on your build.