Mechanism

For our project, we needed a mechanism that could open and close the flowers, essentially making them bloom. Our main challenge was ensuring the movement didn’t feel mechanical or rigid. We wanted it to mimic the natural, fluid motion of a real flower blooming, graceful and organic rather than engineered.

Reference

https://www.youtube.com/watch?v=Y1MOaF7WLTI

While exploring options for the flower-blooming mechanism, we considered a variety of approaches, from origami-inspired designs to threaded rod actuation. Ultimately, I chose a worm gear mechanism, as its movement felt the most organic and closely resembled the natural unfolding of petals.

The mechanism should include the following features:

1. Slots or holders for six sets of petals
2. Dedicated space for LED lights
3. Enclosure for both the motor and the PCB
4. Easy attachment mechanism to connect with the pipe
5. An overall form that feels organic, avoiding bulkiness or harsh geometric shapes
6. Dedicated space for limit switch

I began by designing the worm gear mechanism using Fusion 360. The setup features a central worm and six worm wheels arranged around it. To handle the load from all six wheels, we decided to use a NEMA 17 stepper motor for its torque and reliability.

I referred to a YouTube video to construct the worm and a single worm wheel. While the video was sufficient for designing one wheel, replicating it six times around the central worm with precise alignment proved challenging. To solve this, I calculated the total rotation and evenly divided it into six segments, allowing me to position each wheel accurately around the worm.

https://www.youtube.com/watch?v=qRBLpBxkldc

The next challenge was figuring out how to attach the petals to the worm wheels. Initially, I designed support structures for each layer of petals. However, this approach only worked with satin paper, since it holds its shape well and consists of two layers, making it easier to insert the support.

To make the design more versatile, I shifted to adding holes in the wheels for the petals to be inserted directly. This solution turned out to be much more effective and adaptable.

https://a360.co/4lmHtvC

Here’s the first testing of the mechanism.

I also 3D printed smaller sections of the design to test their functionality and they worked as intended.

Printed one module to see if the limit switch works at the required height.

3D printed the holder for the mechanism to see if it fits the PVC pipe.

The next part was to design the hub that holds the motor and PCB and also connects the mechanism to the stem.

This was the first iteration of the model. I also designed a PCB holder that could be glued to the base of the mechanism, with the PCB screwed securely in place.

However, this setup presented two major issues: first, removing the entire hub for programming the board was cumbersome; second, a 4-core connector needed to be fitted to the bottom of the hub and soldered to the wires, which was difficult to access with the initial design.

So, Jogin helped me in redesigning the hub to be in two parts that can be screwed together. This made it easier to open up when needed. We also added a slot inside the hub to hold the PCB, instead of using a separate piece glued to the base.

Here’s the final design.

https://a360.co/3U7QfBv

I designed a dome to help diffuse the light from the LEDs. I also added side holes to allow filaments and small petals to be inserted.

Design File

The first working prototype.

Next, I designed a holder to secure the pipe firmly to the base.