Five-Axle Stepper Motor Clock

I designed this clock to be small so it would fit inside a top hat. I am making a steam punk costume with a clock inside the hat and I wanted it to have visible gears. Despite the ubiquity of clocks, there is not a lot of easily accessible information on designing a clock from scratch. So, this design took weeks of research and much trial and error. This model is the result and is entirely my own design.

I did not try to make movement mechanism. Instead, I bought a stepper motor and hardware to run the motor at 1 RPM. This motor drives the second hand axle. If there is any interest, I can post more details on the electronics. However, I basically programmed an ardiuno to run the stepper motor.

The bearings in this clock are standard skateboard bearings. I got the cheapest ones I could find ($10 for 8). They are 22mm on the outside and 8mm on the inside and 7mm thick.

This version is actually a five-axle clock. I improved the design to require less gears. See the clock running in "break-In" mode here: https://youtu.be/JpaEKej01mE. You can see there is a little hitch in the gears caused by the 3D printing process. I am running the clock faster than normal to get those bumps to smooth out.

Print Settings

Printer Brand:

LulzBot

Printer:

TAZ 6

Supports:

Yes

Resolution:

.4

Infill:

25

Notes:

Only a couple pieces need supports. Axles two through six are designed to be printed laying on their side. There are .2 mm of slop built into the gear spacing to reduce friction between the gears.

Post-Printing

I had to use small fine-toothed triangular and round files to smooth out the main axle and the sleeves to ensure they were free spinning. Due to the natural inconsistencies of 3D printing vertical columns. You could probably reduce the amount of post print clean up by reducing the layer height. However, I wanted to print faster with a bigger layer height.

The name of the gear tells you the gear tooth could and which axle it belongs on. For example, A2G30-15 is a Axle 2 gear with a 30-tooth wheel and a 15-tooth pinion. The main axle is not numbered. However, the subsequent numbers start from that axle and are numbered going counterclockwise.