Quantity   Component name
1 × old DVD drive for stepper motor extraction
1 × Stepper Motor shield (cheaper than building it myself with 2H-bridges)
1 × stepper/servo
1 × Arduino
1 × a needle :-)
1 × PHOTO-TRANS. SFH309FA-3/4 T1 OSR I’ll give details when I found a working solution :-)
1 × Some IR-LEDs, OP-AMP, some resistors and trimmers, c I’ll give details when I found a working solution :-)