A few weeks ago i say a youtube video short of a guy making a clock using arduino and gears.. and i thought i want to make one too.. So i remix his original design and make one of my own design using tinkercad.. the clock timing will be controlled by an arduino nano and stepper motor.. the whole clock will be powered by a 5v usb cable..

p/s.. it turns out the youtube guy is really into getting attention.. so here's the link to his original design that i remix from.. https://www.instructables.com/Hollow-Clock-4/

I'm going to also put a window on the base of the clock so you can see the gears turns when its operational..

Difficulty level:

3D printing - Easy
Assembly - Easy
Wiring - Easy
Painting - None

So let's get started..

Supplies

Arduino Nano
28BYJ-48 5V DC Stepper Motor
ULN2003 Easy Driver Board
Mini USB female connector
M3 screw - 40mm, 6mm,
M3 lock nut
connector block
plexiglass or acrylic sheet - 3mm
wires with dupont connectors
M3 brass inserts
neodymium magnets 10x5mm ,

And as always a FDM 3d printer to print all the parts..

Step 1: Modelling Using Tinkercad

The hardest part in modelling the clock was making the gears ratio.. since the calculation for the gear ratio for the hour and minute were already done.. all i had to do was make the gears base on the size i wanted the clock to be.. i opted the size to maximize my 3d printer so i made the clock face 20cm diameter.. and all the other gears will follow the sizing from the face gear..

Made the gear using simple using roof and star geometry to get the number of teeth for the gears.. since tinkercad already have the geometry shape for the arduino nano and the stepper motor.. i can easily design the housing and placement of them into the base of clock..

You can find the 3d printed stl files here: www.fay3dlab.com

Floating needle clock

Step 2: Assembly - Electronics

Wiring the stepper motor board to the arduino nano is fairly straight forward..

IN1 - Digital pin D2
IN2 - Digital pin D3
IN3 - Digital pin D4
IN4 - Digital pin D5

You can test the stepper motor running with test-run-code.ino provided in downloaded folder.. make sure the stepper motor is turning counter clockwise.. if its not.. than change the sequence of the 4 IN pin inverted

IN1 - Digital pin D5
IN2 - Digital pin D4
IN3 - Digital pin D3
IN4 - Digital pin D2

Once all the test is done.. you can upload the clock-code.ino.. which i modified an arduino code from shiura to fit into this project.. thank you mr shiura for sharing your code to be remixed..

Step 3: Assembly - Clock Base

First thing is to add 2 M3 brass insert from the front of the window..
Install the arduino, ULN2003 board and stepper motor in place
Test out the wiring before installing the gears
The minute gear should be a tight fit into the stepper motor peg..

Now we need to prepare the window for the base

Currently you can laser cut the shape and holes for the window or manually cut it like i did.. all you need is:

a printer to print the templete for the window
a mini drill to make 2 holes in the window plexiglass
a plexiglass cutter to cut it to fit into the base.. the measurements is 64mm x 99mm

Now that the window is ready we can assemble the rest of the gears

Insert the middle gear and the hour gear into the window.. close it with the plexiglass and add 2 M3 40mm screw through the 2 holes that we drill

The 2 holes on the plexiglass should align with the 2 holes with brass insert on the base.. screw them into place

Test the motor again to see if the gears are loose to turn freely

P/S: i made the gears slightly loose since we all have different printer with different settings and size tolerence.. so the minute gear is going to be like a few degrees off from the exact time later when we fully assemble the clock..

Step 4: Assembly - Clock Face

First thing we need to do is prepare the magnets that will point the hour needle.. at first i used only one magnet to pull the needle magnet but it wasnt strong enough as when at 3pm-9pm angle the hour needle just drops.. so i had to use 2 magnets on the hour face gear to pull the hour needle.. 2 that will pull both north and south pole of the magnet..

Now the assembly is simple.. add the back base cover that has the clock face

Insert the minute gear with the hour needle into place

And then the hour gear with the magnet.. if you look closely i added a small dent on the hour gear so you'll know where it points

And lastly add the front base cover that will keep the 2 gears in place..

Now all we need to do is test the clock gear and motor.. everytime the motor moves a minute.. the stepper motor driver LED will blink.. you can use that to see if the minute gear moves or not..

Once everything is in working order.. you can glue the micro usb board to the position at the back of the base..

I inserted the micro usb into the female usb board and then align it with the cover.. add a bit of glue and close the cover to align it to the notch i added to the base cover

Step 5: Conclusion

Although it looked easy to design and make.. the hard part was tweaking it to fit and work together.. i had to redesign the magnet hour needle several times until i got the exact distance and length so the pull is strong enough.. the gear positioning was also adjusted bit by bit until it catches each other perfectly without and stall.. i had several stall with the gears.. after several iteration it was caused by loose wire on the stepper motor driver board..

In the end.. it took a week to completely finish the print and testing.. i was hoping it was just a weekend project.. turned into a week's project..

I hope you have fun making the floating clock..