Summary

update 2(2016/11/25) added printable spacers and a motor mount plate for 20mm npm motor
update 1(2015/2/6) : added assembly sequence sheet .

this is a simple clock based on a single geared stepper motor which i found in surplus 10 for a dollar... The motor is basically a 1:30 geared motor working at 12v with a 3mm shaft. The single motor is driven by a attiny2313 and l293dd circuit with the coded written in arduino ide. The single motor moves a gear train which in turn moves the minute ring and hour ring. The attiny pulses the motor every minute to move the minute wheel and the hour wheel.

buy at:

https://www.tindie.com/products/ekaggrat/holo-clock-2/

https://www.youtube.com/watch?v=1EtiEFQ4Aqg

Instructions

print all the parts at minimum 0.2mm layer height

bolts : m3 x 45mm 4
m3 x 25 mm 2
m3 x 22 mm 1
m3 x 10 grub screw for motor gear
m3 nut x 7

for npm motor (optional)
m2 x 10 2
m2 nuts 2

for bj25 / bj20 motor
m3 x 15 self tapping screws 2

pcb spacers / cut from any brass/copper tubing ( printable option also )
4.5 outer dia x 3.5 mm inner dia x 12.mm length 2 pieces
4.5 outer dia x 3.5 mm inner dia x 8.5.mm length 4 pieces
4.5 outer dia x 3.5 mm inner dia x 6.5.mm length 2 pieces

for the stepper you can use any 20mm or 25mm diameter geared more than 1:10 ratio, bipolar or unipolar.