Lesson | Flower


Build a mechanical flower that opens up when there is light. This flower uses a few interesting mechanical movements including a push-pull cable to convert rotational movement into a linear movement for a flexible stem. Then the movement is converted back to rotational pivot points to open and close the pedals. The use of the binder clips also means that you are free to create your own flower petals.


  • A5 x Clip link
  • B1 x Clip pivot ring
  • C1 x Clip retainer ring
  • D1 x Clip retainer cap
  • E1 x Clip link base
  • F5 x Binder clips
  • G5 x Petals
  • H1 x Stem mount plate
  • I4 x #6 x 1/2" wood screws
  • J2 x 6-32 x 3/4" machine screws with nylon lock nuts
  • K1 x 1/4" water line/hose
  • L1 x Cable tie
  • M1 x Servo Sock (Positionable)
  • N1 x Cable pull disc

Build Steps

Step 1

slide the 5 clip links [A] into the clip link base slots [B].

Step 2

Slide the cable tie through centre [A] of the clip link base

Step 3

Slide the Clip retainer ring [A] and the clip retainer cap [B] over the base to lock the clip links into place. This will also retain the cable tie. Then use the 2 6-32 x 3/4" machine screws and nylon lock nuts [C] to hold the assembly together.

Step 4

Mount the stem (water tube) in the hole on the stem mount plate [C]. The idea is to have the stem press against the face of the servo sock. Start with #6 x 1/2 screw at position [A] to create a pivot point (you will need to drill a hole). Next mount screw [B] in the middle of the slotted hole.

Then before tightening the screw, firmly press the tube against the Servo Sock to hold it in place. When complete the tube should not slide out of the hole in the plate.

Step 5

Push the clip pivot ring onto the tube [A]

Step 6

Add the 5 binder clips onto the clip pivot ring [A]. Next, rotate them so that they are facing out [B]

Step 7

Slide the upper assembly with the cable tie [A] into the tube.

*Note how the one arm of the binder clip hooks into the clip links [B]

Step 8

Position the disc so that the slot for the end of the cable tie is close to the end of the tube [A]. Next, mount the disc with 2 #6 x 1/2" screws.

*Note you might need to hook up the servo and adjust the position which is outlined in the next step.

Step 9

Hook the servo up to the D8 connection [A] on the control board and rotate the first knob CW. Next, adjust the position of the servo horn [B] so that the disc will be at the position pictured. The flower should be fully open at this position.

*NOTE - you may need to trim the length of the cable tie slightly to fit into the slot.

Step 10

Mount the petals into each of the binder clips.

*Note - Have some fun and create your own petals

Step 11

Connect the Servo to D10 on the control board [A]. Next, connect the sensor to the A5 connection next to D10 then to the light sensor making sure that the orange wire lines up with the "S" on the connection

Step 12

You are done, power up the control board, and the flower will open and close based on the light level the sensor is receiving.