Kinetic Sculpture Infinity

Hi All,

This is my third design of Kinetic sculpture, you can check my design 1 and 2 here

In this design,

• I have improved by gearbox by adding a few spacers that give stability and reduce noise
• It still is motor-based and lightweight, gathering things should not be too difficult to print and assemble.
• The wheel design is like a jigsaw puzzle easy to print and assemble.
• Wheels are reverse compatible with designs 1 and 2

• 3d Printer ( I have used Ender3)
• STL file
• M4 x 25 mm screws - 4 Nos
• M4 x 40 mm Screw - 1 no ( if you get M4 x50 or above, we need spacer2)
• 70 rpm DC geared Motor (3-6v)
• 5V volts old mobile charger
• 5.5mm male and female power connector
• Super Glue
• Box cutter
• Soldering Iron

• To design a gearbox we must first list what we expect out
• RPM: we want (rotations per minute) rpm to be between 5 to 20
• It cannot be too fast or too slow
• We need to reduce the motor RPM to this value
• Torque: should be able to turn the and bear the load/weight of the wheels
• Needs to spin the gear anti-clock and clockwise at the same time
• Both wheels should align
• Motor selection
• There are many types of geared motors available.
• DC gear motor that I choose is commonly available
• Gear reduction
• To reduce RPM from 70 to 10, We need a gear pair with 7:1
• Motor to have minimum teeth of 10
• Mean equates that one of the gears to be 70 (let's assume the back gear)
• The front gear needs to rotate in sync with the back gear but in the opposite direction
• Added a 20T gear that is connected to the back 70T
• Added another 20T that connected to the previous 20T and the 70T front gear
• So when the motor spins clockwise, the back 70T gear moves anti-clock
• The first 20T spins clockwise, and the second 20T spins anti-clock
• The front 70T gear spins clockwise
• So we have achieved
• 10rpm
• two gears that move in the opposite direction

Sorry bit nerdy explanation

• Download STL files from here
• Print Gears with 20% infill, Layer height 0.2mm
• 10T Gear
• 20T Gear -2 no
• 70T Front Gear
• 70T Back Gear
• front_plate
• back_plate (with support)
• Infinity front wheel
• Infinity back wheel
• arms 5 sets (STL file has 4 arms)

I have added labels for easy identification of each part, If you add a query, leave a message below.

It would take 3-4 days to print it all in continuous batches

• Pass an M4x40MM screw in the center hole of the backplate ( from the back)
• If you have M4x50, then use spacer 2 as shown to reduce its length
• Add 70T back gear, use super glue to stick the gear and the screw
• Let this dry
• now add 70T front gear, 20T gears, Motor, 10T gear, and spacer1
• Using 3 - M4x25mm screws fix the front plate of the gearbox
• I have added a gif file to show how the gearbox is assembled
• Connect the power supply to the motor and test how many RPMs this gearbox gives
• Mine gave 10 rpm. one could play with the voltage level to fine-tune the final rpm

• The front and the back wheel have slots in a specific direction
• So the arms will fit only in a specific way, they fit like a jigsaw puzzle
• If you have difficulties in fixing them together, try to remove the elephant's foot using a box cutter
• Use super glue to fix the wheel and the arms

Elephant's Foot: For the first few layers, the distance between the hot-end and bed is less/smaller than 0.2mm, which causes the print to spread on the bed, creating these layers to be larger than the rest. A good video on elephant's foot from Makers Muse, watch it for more info

• Drill holes on your wall to hang the gearbox
• Connect the power supply
• Place the wheel "back" on the gearbox, no need to glue
• Added the wheel "front" by screwing in clockwise, this will interlock with the m4x50mm screw at the center
• Switch on the power supply and enjoy your new Kinetic Sculpture and get mesmerized by its beauty