Week 05 - Kinetic structures

Task #05

The task for the fifth week is to create a kinetic structure consisting of atleast three physical parts with mechanical transmission between them. The physical parts (links) can be made by laser cutting and/or 3D printing.

Turntable

I wanted to make something practical I could use for my final project. I am sticking to the idea of ESP32 with camera. However, I would like to place the module inside a case which would be sitting on top of a turntable - platform which could rotate. It would be powered by 28BYJ-48 stepper motor.

To design the turntable with room for the motor, I dowloaded the 28BYJ-48 stepper motor model and imported it into Fusion.

Now I can start modelling. I created a box with mounting points for the motor and a small hole for cables. I also took advantage of SpurGear library to create gears. I will be using two gears with these parameteres:

⚙️ Gear parameters

Module: 2.0
Num Teeth: 10 and 20
Pressure Angle: 20.0
Backlash: 0.50 mm

It is important to set the same module for both gears.

💡Tip: Add gears in Fusion

UTILITIES -> ADD-INS -> Add-Ins -> SpurGear -> Run. Now, when modelling just click Spur Gear in SOLID -> CREATE -> Spur Gear and fill in the parameters.

The bigger gear consists of two parts which will be glued together after the 3D print. I prepared some aligning holes/pins. The top part of this gear will be gliding on top of the box lid. I will put some lubricant between those two parts so it would run smoother. There is also hole in the center for cables.

And this is the final assembly. I mouted the stepper motor and connected it to ULN2003 driver. Iconnected this driver to Arduino Nano and run simple test script. I followed this tutorial, including wiring. I left 0.5 mm space in diameter between the gear shaft and the lid of the box. It fits perfectly and leaves enough room for spinning.

And short demo video.